Early View

Covers of the Week

Isomerization of Triphenylmethoxyl: The Wieland Free-Radical Rearrangement Revisited a Century Later (p NA)
Gino A. DiLabio, K. U. Ingold, Shuqiong Lin, Grzegorz Litwinienko, Olga Mozenson, Peter Mulder, Thomas T. Tidwell
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201003622

	In 1911, Wieland provided the first demonstration of a radical rearrangement by studying the products obtained in the thermal decomposition of Ph3COOCPh3. In their Communication (DOI:10.1002/anie.201001008), Ingold et al. determine the rate constant for this isomerization both experimentally and by DFT calculations. In contrast to previous photochemically based findings, their results vindicate Wieland\9s observations and thus provide a cautionary tale for photochemists. Photo reprinted courtesy of the Faculty of Chemistry and Pharmacy of the University of Munich.

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Communications

Wieland Rearrangement

Isomerization of Triphenylmethoxyl: The Wieland Free-Radical Rearrangement Revisited a Century Later (p NA)
Gino A. DiLabio, K. U. Ingold, Shuqiong Lin, Grzegorz Litwinienko, Olga Mozenson, Peter Mulder, Thomas T. Tidwell
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201001008

	Old wisdom teaches a new lesson: The rate constant for the isomerization of thermally generated triphenylmethoxyl to Ph2(PhO)C. has been determined both experimentally and by DFT calculations (see scheme), and the results vindicated Wielands 1911 observations and conclusions - in contrast to photochemically based findings.

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Highlights

Methane Monooxygenase

One is Lonely and Three is a Crowd: Two Coppers Are for Methane Oxidation (p NA)
Richard A. Himes, Kevin Barnese, Kenneth D. Karlin
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201003403

	What/where is the active site? The determination of the metal ion content and makeup of the bacterial membrane protein methane monooxygenase (pMMO) has an enigmatic research history, despite protein X-ray structures. A new study appears to settle the issue; the dicopper center facilitates oxidation of methane to methanol. However, the unusual active-site environment leaves many questions for future investigations on the relevant copper-dioxygen chemistry and biochemistry.

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Arylboronates

Expanding the Limits of Organoboron Chemistry: Synthesis of Functionalized Arylboronates (p NA)
Pedro Merino, Tomás Tejero
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201003191

	Form and function: Cross-coupling reactions are fundamental processes for CC bond formation in arene chemistry. But the utility of those reactions is determined by the availability of a suitable number of adequately functionalized substrates. This highlight discusses the preparation of functionalized arylboronates of synthetic utility (see scheme; Fg=functional group).

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Asymmetric Catalysis

Cobalt-Catalyzed Asymmetric Hydrovinylation (p NA)
Dieter Vogt
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201003133

	Back to the first row: A surprisingly simple protocol involving chiral diphosphine complexes of cobalt(II) salts allows the highly enantioselective hydrovinylation of 1,3-dienes in extremely high selectivities and yields.

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Methane Oxidation

Functionalization of Methane in Anaerobic Microorganisms (p NA)
Rudolf K. Thauer
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201002967

	More than one way to skin a cat: Some strictly anaerobic bacteria grow on methane and nitrite, forming CO2 and N2. Recently published experimental evidence suggests the involvement of a NO dismutase and of a particulate methane monooxygenase (pMMO) in the process. Both enzymes are lacking in microorganisms that catalyze anaerobic methane oxidation with sulfate. There are thus at least two pathways that enable anaerobes to use methane as fuel.

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d

A Multi-Faceted Approach to Elucidate the Crystal Structure of D-Ribose: Similarities to Protein Structure Determination (p NA)
Wolfram Saenger
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201002865

	Recalcitrant to crystallization: After 50 years, the crystal structure of open-chain D-ribose has been determined. It can occur as pyranose or furanose, but in the solid sate, only - and -pyranose is found, which contrasts with the -furanose form featured exclusively by nucleosides (for example cytidine; see figure). This difference arises from the structural flexibility of the -furanose ring that easily transforms by pseudorotation from the C2-endo to the C3-endo form in DNA, thus carrying out various functions, whereas pyranose is rigid.

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Sensors

Progress in the Chromogenic Detection of Carbon Monoxide (p NA)
Steven Heylen, Johan A. Martens
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201002569

	Toxic CO concentrations can be detected by a very clear induced color change of the dirhodium complex 1 (see scheme) upon binding of CO, as reported by Esteban et al. Other atmospheric compounds such as H2O, CO2, O2, CH4, SO2, NOx, and volatile organic compounds do not interfere with the CO sensing.

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Communications

Copper Catalysis

Copper-Promoted and Copper-Catalyzed Intermolecular Alkene Diamination (p NA)
Fatima C. Sequeira, Benjamin W. Turnpenny, Sherry R. Chemler
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201003499

	Simply copper: Copper(II)-promoted intra- and intermolecular olefin diaminations bring together two differently functionalized amines into a vicinal relationship. High diastereoselectivity was obtained with chiral alkenes and results of the asymmetric catalysis are promising.

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Supramolecular Chemistry

Head-To-Tail and Heteroleptic Pentanuclear Circular Helicates (p NA)
Kirsty E. Allen, Robert A. Faulkner, Lindsay P. Harding, Craig R. Rice, T. Riis-Johannessen, Melanie L. Voss, Martina Whitehead
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201003342

	Everybody form a circle: Careful design of ligand strands and their reaction with Cu2+ ions leads to the formation of the title helicates. Incorporation of differing numbers of N-donor units within a ligand strand containing a phenyl spacer results in a pentanuclear head-to-tail circular helicate, whereas reaction of two different ligands results in a heteroleptic pentanuclear circular helicate (see picture; green: Cu, red and blue: ligands).

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Asymmetric Catalysis

Isomerization-Induced Asymmetric Coordination Chemistry: From Auxiliary Control to Asymmetric Catalysis (p NA)
Lei Gong, Zhijie Lin, Klaus Harms, Eric Meggers
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201003139

	Asymmetric generator: Chiral (S)-(isopropylsulfinyl)phenol and a more electron-rich methoxy derivative (R=OCH3) are capable of inducing and even catalyzing a chirality-generating trans-cis isomerization of two 2,2-bipyridine ligands in an octahedral coordination sphere of a ruthenium complex.

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Asymmetric Organocatalysis

Metal-Free Direct Asymmetric Aminoxylation of Aldehydes Catalyzed by a Binaphthyl-Based Chiral Amine (p NA)
Taichi Kano, Haruka Mii, Keiji Maruoka
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201002965

	And Im free, metal-free fallin: A metal-free direct asymmetric aminoxylation of aldehydes with the oxoammonium salt 1, generated in situ from TEMPO and benzoyl peroxide (BPO), was found to be catalyzed by a binaphthyl-based secondary amine (S)-2. This method provides a new approach to bench-stable optically active -aminoxy aldehydes as useful chiral building blocks. TMS=trimethylsilyl.

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Asymmetric Synthesis

Organocatalytic Asymmetric Inverse-Electron-Demand Diels-Alder Reaction of Electron-Deficient Dienes and Crotonaldehyde (p NA)
Jun-Long Li, Tai-Ran Kang, Si-Li Zhou, Rui Li, Li Wu, Ying-Chun Chen
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201002912

	Another pathway for enals: The excellent ,-regioselectivity shown in the title reaction under dienamine catalysis efficiently gave highly diastereo- and enantioenriched cyclohexene derivatives with substantial substitution diversity (see scheme; EWG=electron-withdrawing group, TMS=trimethylsilyl).

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Heterocyclic Carbenes

From Bis(N-Alkylimidazole) to Bis(NH-NHC) in Rhenium Carbonyl Complexes (p NA)
Miguel A. Huertos, Julio Pérez, Lucía Riera, Jesús Díaz, Ramón López
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201002879

	Two birds, one stone: A deprotonation-protonation sequence using only one molar equivalent of base and acid transforms two N-alkylimidazole molecules into N-heterocyclic carbene ligands (see scheme; black C, gray H, green F, blue N, red O, cyan Re, yellow S).

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Nanotube Synthesis

One-Step Conversion of Aromatic Hydrocarbon Bay Regions into Unsubstituted Benzene Rings: A Reagent for the Low-Temperature, Metal-Free Growth of Single-Chirality Carbon Nanotubes (p NA)
Eric H. Fort, Lawrence T. Scott
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201002859

	A tube ride: The controlled chemical synthesis of uniform, single-walled carbon nanotubes from short hydrocarbon templates, such as aromatic belts and geodesic nanotube end-caps, by a Diels-Alder cycloaddition/rearomatization strategy requires a potent masked acetylene capable of transforming hydrocarbon bay regions into new unsubstituted benzene rings in a single operation. Nitroethylene has been found to effect such benzannulations (see scheme).

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Gold Catalysis

Gold(I)-Catalyzed Cycloisomerization of Enynes Containing Cyclopropenes (p NA)
Changkun Li, Yi Zeng, Hang Zhang, Jiajie Feng, Yan Zhang, Jianbo Wang
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201002673

	Goldenyne: Gold-catalyzed cycloisomerization reactions of propargyl cyclopropenes afford benzene derivatives in a highly efficient manner. The reaction either proceeds through a mechanism with or without double and triple bond cleavage, depending on the substituents (see scheme).

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Amination

Direct Amination of Secondary Alcohols using Ammonia (p NA)
Dennis Pingen, Christian Müller, Dieter Vogt
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201002583

	Hydrogen shuttle: For the first time secondary alcohols and ammonia are directly converted into primary amines with a selectivity of up to 99 % by using a simple ruthenium/phosphine catalyst (see scheme; R1, R2= alkyl, aryl, alkenyl; M=[Ru3(CO)12]; and L=phosphine ligand).

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Aromaticity

Metal Complexes of Chiral Möbius Aromatic [28]Hexaphyrin(1.1.1.1.1.1): Enantiomeric Separation, Absolute Stereochemistry, and Asymmetric Synthesis (p NA)
Takayuki Tanaka, Tsutomu Sugita, Sumito Tokuji, Shohei Saito, Atsuhiro Osuka
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201002282

	Twist and sort out! Chiral separation of PdII, NiII, and PtII complexes of [28]hexaphyrin(1.1.1.1.1.1) was achieved by HPLC on a chiral stationary phase (see inset for CD trace). The absolute configuration for the PdII complex was determined by X-ray crystallography. Asymmetric metalation of hexaphyrin, achieved with a PdII binap salt, resulted in 23 % ee. This is the first example of asymmetric synthesis of Möbius-twisted molecules.

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NMR Spectroscopy

Solid-State ¹⁷O NMR Spectroscopy of Large Protein-Ligand Complexes (p NA)
Jianfeng Zhu, Eric Ye, Victor Terskikh, Gang Wu
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201002041

	Oxygen, oxygen, everywhere! Poor sensitivity has hindered the development of solid-state 17O NMR spectroscopy as a practical technique for the structural elucidation of protein complexes. However, this has now changed and it has been demonstrated that multinuclear 17O, 27Al, 13C NMR parameters can be used to aid structural refinement for a protein-bound ligand molecule.

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Synthetic Methods

A Direct Entry to Substituted N-Methoxyamines from N-Methoxyamides via N-Oxyiminium Ions (p NA)
Kenji Shirokane, Yusuke Kurosaki, Takaaki Sato, Noritaka Chida
Published Online: Jul 29 2010 3:45AM
DOI: 10.1002/anie.201001127

	Take the direct path: Sequential nucleophilic addition of N-methoxyamides using DIBAL and organometallic reagents provided substituted N-methoxyamines in one pot via five-membered chelated intermediates (see scheme, DIBAL=diisobutylaluminum hydride). The reaction allows functionalization of acyclic amides and macrolactams without a preactivation step, which is generally required for inert amide carbonyl groups.

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Reviews

Applications of DNA

DNA as a Versatile Chemical Component for Catalysis, Encoding, and Stereocontrol (p NA)
Scott K. Silverman
Published Online: Jul 28 2010 9:26AM
DOI: 10.1002/anie.200906345

	Beyond biological DNA: Chemists are exploiting DNA for interesting applications as a catalyst, encoding component, and stereocontrol element. Each of these chemical applications takes advantage of a distinct subset of DNAs properties in ways not known in nature.

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Inside Covers of the Week

Solid-State ¹⁷O NMR Spectroscopy of Large Protein-Ligand Complexes (p NA)
Jianfeng Zhu, Eric Ye, Victor Terskikh, Gang Wu
Published Online: Jul 28 2010 9:26AM
DOI: 10.1002/anie.201004202

	Large biomolecular systems were probed for the first time by solid-state 17O NMR spectroscopy. In their Communication (DOI: 10.1002/anie.201002041), G. Wu and co-workers show that high-quality solid-state 17O NMR spectra can be obtained for large protein-ligand complexes at an ultrahigh magnetic field of 21 T. The sensitivity of solid-state 17O NMR experiments at this field should allow biomolecular systems of up to 300 kDa in size to be tackled.

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Communications

Gold Catalysis

Diastereo- and Enantioselective Gold(I)-Catalyzed Intermolecular Tandem Cyclization/[3+3]Cycloadditions of 2-(1-Alkynyl)-2-alken-1-ones with Nitrones (p NA)
Feng Liu, Deyun Qian, Lei Li, Xiaoli Zhao, Junliang Zhang
Published Online: Jul 28 2010 9:26AM
DOI: 10.1002/anie.201003136

	The mysterious cyclizations of gold: An asymmetric gold(I)-catalyzed formal [3+3] cycloaddition of 2-(1-alkynyl)-2-alken-1-ones with nitrones has been developed. Compound 1 was found to be an effective and reliable chiral catalyst, as well as the commonly used 2, for this gold-catalyzed reaction. Tf=trifluoromethanesulfonyl.

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High-Pressure Chemistry

Pressure-Driven Assembly of Spherical Nanoparticles and Formation of 1D-Nanostructure Arrays (p NA)
Huimeng Wu, Feng Bai, Zaicheng Sun, Raid E. Haddad, Daniel M. Boye, Zhongwu Wang, Hongyou Fan
Published Online: Jul 28 2010 9:26AM
DOI: 10.1002/anie.201001581

	Forced into line: External pressure was used to engineer nanoparticle assembly. Reversible manipulation of the unit-cell dimensions of a 3D ordered nanoparticle array under a hydrostatic pressure field enabled the fine-tuning of the interparticle distance. Under a uniaxial pressure field, nanoparticles were forced to contact and coalesce into nanorods or nanowires and ordered ultrahigh-density arrays (see picture; small arrows denote pressure).

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Macrocycles

Hexameric Palladium(II) Terpyridyl Metallomacrocycles: Assembly with 4,4-Bipyridine and Characterization by TWIM Mass Spectrometry (p NA)
Sujith Perera, Xiaopeng Li, Monica Soler, Anthony Schultz, Chrys Wesdemiotis, Charles N. Moorefield, George R. Newkome
Published Online: Jul 28 2010 9:26AM
DOI: 10.1002/anie.200906198

	TWIM peaks: A macrocycle containing 12 PdII terpyridyl centers was assembled using 4,4-bipyridyl ligands and characterized by NMR and traveling wave ion mobility mass spectrometry (TWIM-MS). The macrocyclic architecture was also examined by tandem mass spectrometry and collisionally activated dissociation (CAD) experiments (see picture; C gray, N blue, Pd orange), and the resulting fragments were monitored by time-of-flight mass analysis.

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Book Reviews

Organic Azides Syntheses and Applications. Edited by Stefan Bräse and Klaus Banert. (p NA)
Gwilherm Evano
Published Online: Jul 28 2010 1:58AM
DOI: 10.1002/anie.201003406

	John Wiley & Sons, Hoboken 2009. 536 pp., hardcover 139.00. - ISBN 978-0470519981

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Communications

Supramolecular Ligands

PhthalaPhos: Chiral Supramolecular Ligands for Enantioselective Rhodium-Catalyzed Hydrogenation Reactions (p NA)
Luca Pignataro, Stefano Carboni, Monica Civera, Raffaele Colombo, Umberto Piarulli, Cesare Gennari
Published Online: Jul 28 2010 1:58AM
DOI: 10.1002/anie.201002958

	Interligand hydrogen bonding of chiral monodentate phosphite ligands bearing H-bond donor and acceptor groups leads to formation of supramolecular bidentate ligands, rhodium complexes of which (see picture) afford excellent enantiomeric excesses in catalyzed hydrogenation of classical benchmark and industrially relevant substrates. cod=1,5-cyclooctadiene.

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Catalysis in Water

CH Bond Functionalization in Water Catalyzed by Carboxylato Ruthenium(II) Systems (p NA)
Percia B. Arockiam, Cédric Fischmeister, Christian Bruneau, Pierre H. Dixneuf
Published Online: Jul 28 2010 1:58AM
DOI: 10.1002/anie.201002870

	In water its better: In-situ-generated [Ru(O2CR)2(arene)] catalysts efficiently perform the direct ortho-arylation of functional arenes with chloroarenes or chloroheterocycles in water (see scheme; KOPiv=potassium pivalate), without the need for a surfactant. The activity of these catalysts is higher in water than in organic solvents.

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Cell-Permeable Probes

Glucose-Mediated Assembly of Phenylboronic Acid Modified CdTe/ZnTe/ZnS Quantum Dots for Intracellular Glucose Probing (p NA)
Weitai Wu, Ting Zhou, Alexandra Berliner, Probal Banerjee, Shuiqin Zhou
Published Online: Jul 28 2010 1:58AM
DOI: 10.1002/anie.201001508

	Effective, if dotty: Quantum-dot (QD) emission was modulated through the reversible covalent bonding of glucose to boronic acids on the surface of the QDs (see picture). The highly selective ratiometric probe was sensitive to glucose in the physiologically important concentration range of 0.4-20.0 mM and was used to determine the amount of glucose within living cells.

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Graphene-Based Sensor

A Graphene Oxide-Organic Dye Ionic Complex with DNA-Sensing and Optical-Limiting Properties (p NA)
Janardhan Balapanuru, Jia-Xiang Yang, Si Xiao, Qiaoliang Bao, Maryam Jahan, Lakshminarayana Polavarapu, Ji Wei, Qing-Hua Xu, Kian Ping Loh
Published Online: Jul 28 2010 1:58AM
DOI: 10.1002/anie.201001004

	A charge-transfer complex between graphene oxide (GO) and pyrene dye PNPB has been synthesized by a simple ion-exchange process. Its highly specific interactions with DNA compared to other biomolecules (see scheme) allows selective and rapid detection of DNA in biological mixtures. It also exhibits broadband optical limiting.

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Enzyme Catalysis

The Enzymatic Asymmetric Conjugate Umpolung Reaction (p NA)
Carola Dresen, Michael Richter, Martina Pohl, Steffen Lüdeke, Michael Müller
Published Online: Jul 28 2010 1:58AM
DOI: 10.1002/anie.201000632

	The Stetter reaction employs synthetically useful umpolung reactivity to provide catalytic access to 1,4-bifunctional molecules. The first enzymatic 1,4-addition is described, with the ThDP-dependent enzyme PigD, which makes the challenging asymmetric intermolecular Stetter reaction accessible.

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Zintl Ions

[Ag(Sn₉Sn₉)]^5-: A Homoleptic Silver Complex of A Dimeric Sn₉ Zintl Anion (p NA)
Jian-Qiang Wang, Bernhard Wahl, Thomas F. Fässler
Published Online: Jul 28 2010 1:58AM
DOI: 10.1002/anie.200907228

	Finally, a dimeric nonastannide Zintl anion: The cluster anion [Ag(Sn9Sn9)]5- (1; see picture; blue Sn, red Ag) is obtained from Zintl anion [Sn9]4- by an oxidative coupling reaction. An X-ray structure determination reveals that the SnSn exo bond is also supported by a silver cation. Moreover, 1 is the first cluster consisting only of silver and tin atoms.

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Highlights

Homogeneous Catalysis

State-of-the-Art Catalysts for Hydrogenation of Carbon Dioxide (p NA)
Christopher Federsel, Ralf Jackstell, Matthias Beller
Published Online: Jul 27 2010 3:42AM
DOI: 10.1002/anie.201000533

	Efficiency is key: Nozaki and co-workers managed to achieve very high turnover numbers for the reduction of carbon dioxide to formic acid using an active Iridium(III)-pincer complex 1. This highlight compares Nozakis work to previously reported state-of-the-art catalysts.

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Communications

Nacre Paper

Supramolecular Control of Stiffness and Strength in Lightweight High-Performance Nacre-Mimetic Paper with Fire-Shielding Properties (p NA)
Andreas Walther, Ingela Bjurhager, Jani-Markus Malho, Janne Ruokolainen, Lars Berglund, Olli Ikkala
Published Online: Jul 27 2010 3:42AM
DOI: 10.1002/anie.201001577

	Taking the heat: Hard/soft core/shell colloidal building blocks allow large-scale self-assembly to form nacre-mimetic paper. The strength and stiffness of this material can be tailored by supramolecular ionic bonds. These lightweight biomimetic materials show excellent and tunable mechanical properties and heat and fire-shielding capabilities.

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Author Profiles

José Barluenga (p NA)

Published Online: Jul 27 2010 3:42AM
DOI: 10.1002/anie.201002717

	If I could be anyone for a day, I would be Christopher Columbus at the time he reached America for the first time. If I were not scientist, I would be a veterinary surgeon.

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Reviews

Carbon Nanostructures

Nanostructured Carbonaceous Materials from Molecular Precursors (p NA)
Tobias N. Hoheisel, Stephen Schrettl, Ruth Szilluweit, Holger Frauenrath
Published Online: Jul 26 2010 10:05AM
DOI: 10.1002/anie.200907180

	Promising solutions in emerging fields such as microelectronics, efficient energy storage, and sustainable chemical technology are provided by carbon nanostructured materials. New methods for their preparation will be required that afford functional carbon materials with controlled surface chemistry, mesoscopic morphology, and carbon microstructure. Recent approaches starting from molecular precursors may open up new avenues in this regard.

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Covers of the Week

Palladium-Catalyzed Coupling of Aldehyde Hydrazones: Practical Synthesis of Triazolopyridines and Related Heterocycles (p NA)
Oliver R. Thiel, Michal M. Achmatowicz, Andreas Reichelt, Robert D. Larsen
Published Online: Jul 26 2010 10:05AM
DOI: 10.1002/anie.201004361

	Pharmaceutically active compounds and their intermediates require selective, efficient, and robust syntheses that utilize green chemistry principles. In their Communication (DOI: 10.1002/anie.20101999) O. R. Thiel, M. M. Achmatowicz and co-workers describe a two-step procedure involving selective palladium-catalyzed carbon-nitrogen bond formation followed by a clean oxidative cyclization that affords access to a variety of bicyclic and tricyclic heteroaromatic scaffolds.

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Communications

Metal Nanocrystals

Size- and Shape-Selective Synthesis of Metal Nanocrystals and Nanowires Using CO as a Reducing Agent (p NA)
Yijin Kang, Xingchen Ye, Christopher B. Murray
Published Online: Jul 26 2010 10:05AM
DOI: 10.1002/anie.201003383

	Putting the pedal to the metal: A facile strategy for the synthesis of metal nanocrystals is demonstrated that employs carbon monoxide as a reducing agent. Highly monodisperse platinum nanocubes, spherical palladium nanocrystals, and ultrathin gold nanowires can be produced within 15 minutes.

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Ligand Design

Electron-Donating and Rigid P-Stereogenic Bisphospholane Ligands for Highly Enantioselective Rhodium-Catalyzed Asymmetric Hydrogenations (p NA)
Xiaowei Zhang, Kexuan Huang, Guohua Hou, Bonan Cao, Xumu Zhang
Published Online: Jul 26 2010 10:05AM
DOI: 10.1002/anie.201002990

	More electron donating, more rigid: A new highly electron-donating P-stereogenic bisphospholane ligand (ZhangPhos) was synthesized in a practical and highly enantioselective manner from a commercially available chiral source. Better or comparable enantioselectivities and reactivities than TangPhos were achieved in rhodium-catalyzed hydrogenation of various functionalized olefins (see scheme; nbd=3,5-norbornadiene).

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Asymmetric Catalysis

Chiral Phosphoric Acid Catalyzed Peroxidation of Imines (p NA)
Wenhua Zheng, Lukasz Wojtas, Jon C. Antilla
Published Online: Jul 26 2010 10:05AM
DOI: 10.1002/anie.201002972

	Something to COO about: The title reaction provides direct access to -amino peroxides with high enantioselectivity (see scheme). The phosphoric acid catalyst is thought to activate both the nucleophile and electrophile through hydrogen-bonding interactions.

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Subcomponent Assembly

Subcomponent Assembly and Transmetalation of Dinuclear Helicates (p NA)
Johannes Dömer, J. Chris Slootweg, Florian Hupka, Koop Lammertsma, F. Ekkehardt Hahn
Published Online: Jul 26 2010 10:05AM
DOI: 10.1002/anie.201002776

	Only available as helicates: Dinuclear zinc and nickel complexes bearing previously inaccessible N,S-N,S ligands have been obtained in subcomponent self-assembly reactions from complexes bearing two 2-thiolatobenzaldehyde ligands and 4,4-diaminodiphenylmethane. Both complexes react with Pd(OAc)2 by transmetalation to give the dinuclear palladium complex (see scheme).

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NMR Signal Enhancement

Continuous ¹H and ¹³C Signal Enhancement in NMR and MRI Using Parahydrogen and Hollow-Fiber Membranes (p NA)
Meike Roth, Petra Kindervater, Hans-Peter Raich, Joachim Bargon, Hans W. Spiess, Kerstin Münnemann
Published Online: Jul 26 2010 10:05AM
DOI: 10.1002/anie.201002725

	Parahydrogen-induced polarization is used for the continuous generation of hyperpolarized molecules. Constant 1H and 13C NMR signal enhancement is demonstrated using a continuous delivery of parahydrogen by hollow fiber membranes (see picture, left), allowing the acquisition of two-dimensional NMR signals requiring multiple acquisitions with constant initial polarization.

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Single-Molecule Magnets

Coupling Dy₃ Triangles Enhances Their Slow Magnetic Relaxation (p NA)
Ian J. Hewitt, Jinkui Tang, N. T. Madhu, Christopher E. Anson, Yanhua Lan, Javier Luzon, Mael Etienne, Roberta Sessoli, Annie K. Powell
Published Online: Jul 26 2010 10:05AM
DOI: 10.1002/anie.201002691

	Twos company: Coupling two Dy3 triangles to give Dy6 (see picture; Dy blue, Cl green, O red) leads to a dramatic enhancement of the barrier height to magnetization reversal. The enhancement has been rationalized by single-crystal magnetometry measurements and ab initio calculations.

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Bowl-Shaped Radicals

A Bowl-Shaped ortho-Semiquinone Radical Anion: Quantitative Evaluation of the Dynamic Behavior of Structural and Electronic Features (p NA)
Akira Ueda, Kanako Ogasawara, Shinsuke Nishida, Tomoaki Ise, Tomohiro Yoshino, Shigeaki Nakazawa, Kazunobu Sato, Takeji Takui, Kazuhiro Nakasuji, Yasushi Morita
Published Online: Jul 26 2010 10:05AM
DOI: 10.1002/anie.201002626

	Dish it up: The first bowl-shaped o-semiquinone radical with a sodium cation (see picture) has been synthesized, and its 3D spin- and charge-delocalized nature and redox properties have been evaluated. The concave-convex dynamic behavior of the ion pair was also investigated in a quantitative manner using ESR and ENDOR/TRIPLE measurements and sophisticated DFT calculations.

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Nanoparticles

Low-Symmetry Iron Oxide Nanocrystals Bound by High-Index Facets (p NA)
Jingzhou Yin, Zhinan Yu, Feng Gao, Jianjun Wang, Huan Pang, Qingyi Lu
Published Online: Jul 26 2010 10:05AM
DOI: 10.1002/anie.201002557

	Just the shape of it: Tetrakaidecahedral (see picture, left) and oblique parallelepiped (right) -Fe2O3 polyhedra with exposed high-index facets were obtained in high yield. Magnetic studies show that these two forms of iron oxide have distinct magnetic properties owing to their different shapes and different exposed high-indexed facets.

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Cyclic Imides

Synthesis of Cyclic Imides from Simple Diols (p NA)
Jian Zhang, Muthaiah Senthilkumar, Subhash Chandra Ghosh, Soon Hyeok Hong
Published Online: Jul 26 2010 10:05AM
DOI: 10.1002/anie.201002136

	Theres something imide so strong: Cyclic imides were synthesized from simple diols with primary amines in a single step using an in-situ-generated ruthenium catalytic system. The atom-economical and operatively simple syntheses of succinimides, phthalimides, and glutarimides, which are important building blocks in natural products and drugs, were demonstrated.

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Synthetic Methods

Palladium-Catalyzed Coupling of Aldehyde-Derived Hydrazones: Practical Synthesis of Triazolopyridines and Related Heterocycles (p NA)
Oliver R. Thiel, Michal M. Achmatowicz, Andreas Reichelt, Robert D. Larsen
Published Online: Jul 26 2010 10:05AM
DOI: 10.1002/anie.201001999

	The palladium-catalyzed intermolecular coupling of aldehyde-derived hydrazones with chloroazines, followed by oxidative cyclization under mild conditions afforded access to a broad variety of bicyclic heterocyclic scaffolds that have potential for use in drug discovery.

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Reactions in Supercritical Water

Towards Understanding the Catalytic Reforming of Biomass in Supercritical Water (p NA)
Stefan Rabe, Maarten Nachtegaal, Thomas Ulrich, Frédéric Vogel
Published Online: Jul 26 2010 10:05AM
DOI: 10.1002/anie.201001160

	A critical point: The function of a working ruthenium catalyst during the reforming of ethanol in supercritical water was studied in situ using X-ray absorption spectroscopy (see picture). The reforming of ethanol over a supported ruthenium catalyst in sub- and supercritical water is suggested to proceed by the same mechanism as steam reforming at low pressures.

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Reviews

Drug Discovery

On the Reach of Chemical Synthesis: Creation of a Mini-Pipeline from an Academic Laboratory (p NA)
Rebecca M. Wilson, Samuel J. Danishefsky
Published Online: Jul 26 2010 5:50AM
DOI: 10.1002/anie.201000775

	Successful journey: This retrospective Review describes investigations into the total synthesis and evaluation of biologically active small molecules (such as iso-fludelone; see structure), as well as the development of a program directed toward the chemical synthesis of therapeutically relevant larger molecules, including the glycoprotein erythropoietin.

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Communications

Metal-Metal Interactions

A Mercury-Antimony Interaction (p NA)
Tzu-Pin Lin, Casey R. Wade, Lisa M. Pérez, François P. Gabbaï
Published Online: Jul 26 2010 5:50AM
DOI: 10.1002/anie.201002995

	Fatal attraction: As a result of a unique iodide push-stibonium pull effect, the dinuclear complex (see picture) displays an unprecedented HgSb interaction. The existence of this interaction was examined experimentally and theoretically.

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Asymmetric Aminoxylation

Chiral Brønsted Acid Catalyzed Enantioselective -Aminoxylation of Enecarbamates (p NA)
Min Lu, Yunpeng Lu, Di Zhu, Xiaofei Zeng, Xinsheng Li, Guofu Zhong
Published Online: Jul 26 2010 5:50AM
DOI: 10.1002/anie.201002640

	The practically simple, highly enantioselective title reaction extends the substrate scope for the -aminoxylation to linear and aromatic ketones, allowing convergent and stereoselective access to valuable -hydroxy ketones, -amino alcohols, and cis-oxazolidinones. An=antrhyl, M.S.=molecular sieves.

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Self-Assembly

Regulation of a Real-Time Self-Healing Process in Organogel Tissues by Molecular Adhesives (p NA)
Pritam Mukhopadhyay, Norifumi Fujita, Akihiko Takada, Takanori Kishida, Michihiro Shirakawa, Seiji Shinkai
Published Online: Jul 26 2010 5:50AM
DOI: 10.1002/anie.201001382

	Say cheeeese! The thixotropic processes that occur in a naphthalenediimide-based organogel can be imaged in real time by TEM and AFM (see picture). The self-assembled 1D fibers disintegrate under mechanical stress and undergo a self-healing process during a resting time to reconstitute the 1D fibers.

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Reviews

Carbon Dioxide Capture

Carbon Dioxide Capture: Prospects for New Materials (p NA)
Deanna M. DAlessandro, Berend Smit, Jeffrey R. Long
Published Online: Jul 22 2010 2:59PM
DOI: 10.1002/anie.201000431

	Getting CO2 under control: This Review highlights the challenges for carbon capture and storage technologies which have been proposed to reduce CO2 emissions from large point sources. The most recent developments in new materials and emerging concepts for CO2 separations by absorption, adsorption, and membranes, amongst other approaches, are discussed, with particular attention on progress in the burgeoning field of metal-organic frameworks (see example).

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Minireviews

BioMOFs

BioMOFs: Metal-Organic Frameworks for Biological and Medical Applications (p NA)
Alistair C. McKinlay, Russell E. Morris, Patricia Horcajada, Gérard Férey, Ruxandra Gref, Patrick Couvreur, Christian Serre
Published Online: Jul 22 2010 2:59PM
DOI: 10.1002/anie.201000048

	New packaging: A tremendous number of drugs have been developed but not applied further owing to poor bioavailability. To solve this problem, stable nontoxic metal-organic frameworks have been developed as drug-delivery vehicles and even as bioactive species in their own right.

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Communications

Mesoporous Materials

A Room-Temperature Reactive-Template Route to Mesoporous ZnGa₂O₄ with Improved Photocatalytic Activity in Reduction of CO₂ (p NA)
Shi Cheng Yan, Shu Xin Ouyang, Jun Gao, Ming Yang, Jian Yong Feng, Xiao Xing Fan, Li Juan Wan, Zhao Sheng Li, Jin Hua Ye, Yong Zhou, Zhi Gang Zou
Published Online: Jul 22 2010 2:59PM
DOI: 10.1002/anie.201003270

	Multimetal mesoporous materials MGa2O4 (M=Zn, Ni, Co) can be synthesized by ion-exchange reactions of colloidal mesoporous NaGaO2 (see scheme with TEM images), which acts as both template and precursor, so that a template-removal process can be dispensed with.

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cine

Selective cine Substitution of 1-Arylethenyl Acetates with Arylboron Reagents and a Diene/Rhodium Catalyst (p NA)
Jung-Yi Yu, Ryosuke Shimizu, Ryoichi Kuwano
Published Online: Jul 22 2010 2:59PM
DOI: 10.1002/anie.201002745

	When the crowd says Bo: A carbon-carbon bond is selectively formed at the position of 1-arylethenyl acetate when the alkenyl substrate is reacted with arylboronic acids in the presence of a cycloocta-1,5-diene/rhodium catalyst. The choice of the ligand is crucial for the unusual cine substitution.

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Niobium Compounds

-Organoniobium Compounds with [NbR₄]^- and NbR₄ Stoichiometries (p NA)
Pablo J. Alonso, Irene Ara, Ana B. Arauzo, M. Angeles García-Monforte, Babil Menjón, Conrado Rillo
Published Online: Jul 22 2010 2:59PM
DOI: 10.1002/anie.201002666

	Securely nested: The first examples of -organoniobium compounds with [NbIIIR4]- and NbIVR4 stoichiometries are reported. The Nb centers within the [Nb(C6Cl5)4]q- units (q=0, 1) are located in triakis tetrahedral environments formed by the combination of inner NbC4 (see picture; gray) and outer NbCl4 (green) tetrahedra.

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Protein Synthesis

Synthesis of the Rheb and K-Ras4B GTPases (p NA)
Yong-Xiang Chen, Sebastian Koch, Katharina Uhlenbrock, Katrin Weise, Debapratim Das, Lothar Gremer, Luc Brunsveld, Alfred Wittinghofer, Roland Winter, Gemma Triola, Herbert Waldmann
Published Online: Jul 22 2010 2:59PM
DOI: 10.1002/anie.201001884

	Now available! Farnesylated and carboxymethylated Rheb (see picture) and K-Ras4B GTPases were synthesized in useful amounts by a combination of expressed protein ligation and solid-phase lipopeptide synthesis. The functionality of the proteins was proven by biochemical, biophysical, and cell-based investigations.

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Asymmetric Amplification

Asymmetric Amplification in Phosphoric Acid Catalyzed Reactions (p NA)
Nan Li, Xiao-Hua Chen, Shi-Ming Zhou, Shi-Wei Luo, Jin Song, Lei Ren, Liu-Zhu Gong
Published Online: Jul 22 2010 2:59PM
DOI: 10.1002/anie.201001723

	An ee amp: Asymmetric amplification in reactions catalyzed by phosphoric acids arose from the formation of less soluble supramolecular structures (see scheme; O red, P yellow, C gray, H white) of the racemic phosphoric acids that participate in hydrogen bonds with the crystalline water molecules. The finding shows that highly enantioselective reactions can be observed by using non-optically pure phosphoric acids.

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Azo Compounds

Copper-Catalyzed Aerobic Oxidative Dehydrogenative Coupling of Anilines Leading to Aromatic Azo Compounds using Dioxygen as an Oxidant (p NA)
Chun Zhang, Ning Jiao
Published Online: Jul 22 2010 2:59PM
DOI: 10.1002/anie.201001651

	In the air tonight: A novel approach to symmetric and unsymmetric aromatic azo compounds from simple anilines catalyzed by inexpensive CuBr has been disclosed. Air (or dioxygen) was used as an oxidant under mild reaction conditions, with H2O as the byproduct, to make this transformation environmentally benign and very easy to handle.

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Vibrational Spectroscopy

Chirality Recognition in Menthol and Neomenthol: Preference for Homoconfigurational Aggregation (p NA)
Merwe Albrecht, Jan Will, Martin A. Suhm
Published Online: Jul 22 2010 2:59PM
DOI: 10.1002/anie.201001565

	Cool chirality: L-Menthol (see ball-and-stick model), a most important fragrance, is characterized in terms of its conformation, selective aggregation, and sublimation. The data indicate a preference for homoconfigured aggregates.

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Copper Monooxygenases

The First Catalytic Tyrosinase Model System Based on a Mononuclear Copper(I) Complex: Kinetics and Mechanism (p NA)
Malte Rolff, Julia Schottenheim, Gerhard Peters, Felix Tuczek
Published Online: Jul 22 2010 2:59PM
DOI: 10.1002/anie.201000973

	Ready steady go! The copper(I) complex 1 not only catalyzes the oxygenation of di-tert-butylphenol (DTBP-H) to di-tert-butylquinone (DTBQ) in a tyrosinase-like fashion, but also allows the reactive cycle to be studied in a stepwise and controlled manner. This feature opens new insights into the individual stages of the tyrosinase reaction, phenol hydroxylation, and release of the product as quinone. The implications for the enzymatic reaction are discussed.

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Metal-Organic Frameworks

Reduction of a Metal-Organic Framework by an Organometallic Complex: Magnetic Properties and Structure of the Inclusion Compound [(⁵-C₅H₅)₂Co]_0.5@MIL-47(V) (p NA)
Mikhail Meilikhov, Kirill Yusenko, Antonio Torrisi, Bettina Jee, Caroline Mellot-Draznieks, Andreas Pöppl, Roland A. Fischer
Published Online: Jul 22 2010 2:59PM
DOI: 10.1002/anie.200907126

	The stoichiometric reduction of the MIL-47(V) framework (see picture; green VO6 octahedra) was performed using cobaltocene as an organometallic reducing agent. The formation of a mixed-valence compound with a V3+/V4+ ratio of 1:1 was confirmed by magnetic susceptibility measurements. Incorporation of cobaltocene into the MIL-47(V) framework can be reversed upon treatment with water.

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Book Reviews

Mirror-Image Asymmetry An Introduction to the Origin and Consequences of Chirality. By James P. Riehl. (p NA)
Josep M. Ribó
Published Online: Jul 22 2010 2:59PM
DOI: 10.1002/anie.201003290

	John Wiley & Sons, Hoboken, 2010. 250 pp., softcover 43.50. - ISBN 978-0470387597

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Communications

Water Splitting

Light-Induced Water Splitting with Hematite: Improved Nanostructure and Iridium Oxide Catalysis (p NA)
S. David Tilley, Maurin Cornuz, Kevin Sivula, Michael Grätzel
Published Online: Jul 21 2010 10:40AM
DOI: 10.1002/anie.201003110

	Revved-up rust! Light-induced water splitting over iron oxide (hematite) has been achieved by using a particle-assisted deposition technique and IrO2-based surface catalysis. Photocurrents in excess of 3 mA cm-2 were obtained at +1.23 V versus the reversible hydrogen electrode under AM 1.5 G 100 mW cm-2 simulated sunlight. These photocurrents are unmatched by any other oxide-based photoanode. FTO=fluorine-doped tin oxide.

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Catalytic Intermediates

Isolation of Catalytic Intermediates in Hydroamination Reactions: Insertion of Internal Alkynes into a Zirconium-Amido Bond (p NA)
David C. Leitch, Courtney S. Turner, Laurel L. Schafer
Published Online: Jul 21 2010 10:40AM
DOI: 10.1002/anie.201001927

	Insert alkyne to continue: Reaction of a bis(ureate) zirconium dimethylamido complex with electron-rich alkynes leads to vinylamine insertion products (see scheme). The insertion of CC unsaturated bonds into MN bonds is proposed as a key step in lanthanide chemistry and, more recently, hydroamination reactions catalyzed by Group 4 metals. For the first time, these elusive intermediates have been isolated and characterized on a catalytically active d0-metal center.

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Isomerization

Tuning the cis/trans Conformer Ratio of Xaa-Pro Amide Bonds by Intramolecular Hydrogen Bonds: The Effect on PPII Helix Stability (p NA)
Michael Kuemin, Yvonne A. Nagel, Sabine Schweizer, Fabien W. Monnard, Christian Ochsenfeld, Helma Wennemers
Published Online: Jul 21 2010 10:40AM
DOI: 10.1002/anie.201001851

	The attraction of H-bonding: Proline derivatives with a C4-endo ring pucker and a preference for the trans amide conformer are introduced as building blocks to tune the cis/trans amide conformer ratio in Xaa-Pro bonds within peptides. Noncovalent interactions such as hydrogen bonding between the substituent at C4 of the proline ring and the amide backbone are key for favoring or disfavoring the trans conformer (see picture).

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Stereoselectivity

Enamine versus Oxazolidinone: What Controls Stereoselectivity in Proline-Catalyzed Asymmetric Aldol Reactions? (p NA)
Akhilesh K. Sharma, Raghavan B. Sunoj
Published Online: Jul 21 2010 10:40AM
DOI: 10.1002/anie.201001588

	Take the right path: Comparison of the oxazolidinone and enamine pathways in enantioselective aldol reactions by using density functional and ab initio transition states reveals that the oxazolidinone route does not provide the correct stereochemical outcome (see picture), whereas the enamine pathway predicts the correct stereoselectivity.

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CO

A Shape-Persistent Organic Molecular Cage with High Selectivity for the Adsorption of CO₂ over N₂ (p NA)
Yinghua Jin, Bret A. Voss, Richard D. Noble, Wei Zhang
Published Online: Jul 21 2010 10:40AM
DOI: 10.1002/anie.201001517

	Carbon capture in an organic cage: A shape-persistent, organic prismatic molecular cage (see structure) was synthesized in one step and high yield from readily accessible starting materials through dynamic covalent chemistry. The resulting cage molecule exhibited high selectivity for the adsorption of CO2 over N2 and thus shows promise as a carbon-capture material.

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NMR Spectroscopy

Scavenging Free Radicals To Preserve Enhancement and Extend Relaxation Times in NMR using Dynamic Nuclear Polarization (p NA)
Pascal Miéville, Puneet Ahuja, Riddhiman Sarkar, Sami Jannin, Paul R. Vasos, Sandrine Gerber-Lemaire, Mor Mishkovsky, Arnaud Comment, Rolf Gruetter, Olivier Ouari, Paul Tordo, Geoffrey Bodenhausen
Published Online: Jul 21 2010 10:40AM
DOI: 10.1002/anie.201000934

	Vitamin C for longer lifetimes: N-oxide radicals that are widely used for dynamic nuclear polarization can be reduced by scavengers such as sodium ascorbate (vitamin C) during the dissolution process, thus diminishing losses of polarization during the transfer and extending transverse and longitudinal relaxation times in NMR spectroscopy (see picture).

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Spin-Labeled RNA

Probing Secondary Structures of Spin-Labeled RNA by Pulsed EPR Spectroscopy (p NA)
Giuseppe Sicoli, Falk Wachowius, Marina Bennati, Claudia Höbartner
Published Online: Jul 21 2010 10:40AM
DOI: 10.1002/anie.201000713

	Tempo, TEMPO! Spin-labeled RNAs are readily prepared by postsynthetic modification of RNA. This approach provides access to paramagnetic oligonucleotides with position-specific probes in cytidine, adenosine, and guanosine nucleobases (CT, AT, GT, respectively). In this way alternative RNA secondary structures can be investigated by distance measurements using pulsed EPR spectroscopy.

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Ultrathin Films

Covalent Layer-by-Layer Assembly and Solvent Memory of Multilayer Films from Homobifunctional Poly(dimethoxysilane) (p NA)
Rohama Gill, Muhammad Mazhar, Olivier Félix, Gero Decher
Published Online: Jul 21 2010 10:40AM
DOI: 10.1002/anie.200907161

	Catching the end groups: A simple procedure was used for the covalent layer-by-layer assembly of homobifunctional H2N-poly(dimethoxysilane)-NH2 on SiO2 surfaces that leads to robust layer-by-layer films of optical quality (see picture; photo on left) despite the use of non-purified commercial starting materials. The films show a solvent memory for swelling and de-swelling when immersed in the corresponding solvent for each polymer.

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Author Profiles

Thomas Braun (p NA)

Published Online: Jul 21 2010 10:40AM
DOI: 10.1002/anie.201004120

	The three qualities that make a good scientist are creativity, persistence, and knowledge. My favorite subject at school was chemistry, but also history.

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Reviews

Drug Delivery

Poly(ethylene glycol) in Drug Delivery: Pros and Cons As Well as Potential Alternatives (p NA)
Katrin Knop, Richard Hoogenboom, Dagmar Fischer, Ulrich S. Schubert
Published Online: Jul 20 2010 11:23AM
DOI: 10.1002/anie.200902672

	All-round talent PEG? Poly(ethylene glycol) (PEG) surrounds us in our everyday lives and, particularly in drug-delivery applications, counts as a gold standard. This omnipresent polymer is explored from different angles - advantages and disadvantages are evaluated together with alternative polymers.

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Highlights

Trityloxy Radical

The Rearrangement of the Trityloxy Radical: Sherlock Holmes Most Recent Case (p NA)
Götz Bucher
Published Online: Jul 20 2010 11:23AM
DOI: 10.1002/anie.201002914

	Reopening the case: One hundred years after Wielands original publication, the rearrangement of the trityloxy radical was studied by K. Ingold et al., who investigated the title reaction with the logical reasoning and intellectual prowess of true detectives.

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RNA Interference

Proof of RNA Interference in Humans after Systemic Delivery of siRNAs (p NA)
Jens Kurreck
Published Online: Jul 20 2010 11:23AM
DOI: 10.1002/anie.201002867

	Great hope is placed in the use of RNA interference in the development of novel therapeutics. Recently, small interfering RNAs (siRNAs) were delivered to tumor cells of melanoma patients by nanoparticles consisting of a cyclodextrin polymer, and polyethylene glycol coupled to adamantane and transferrin (see picture). It was demonstrated that the target mRNA in the patients was degraded by a specific RNA interference mechanism.

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Mechanochemistry

Reconfiguration of Stereoisomers under Sonomechanical Activation (p NA)
Giancarlo Cravotto, Pedro Cintas
Published Online: Jul 20 2010 11:23AM
DOI: 10.1002/anie.201001360

	Lets twist to the music: In an unprecedented reconfiguration of thermally stable atropisomers, mechanical stress induced by ultrasound waves on a polymer-bound substrate (see structure) did effectively cause racemization facilitating enantiomer interconversion.

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Communications

Iterative Synthesis

Asymmetric Conjugate Silyl Transfer in Iterative Catalytic Sequences: Synthesis of the C7-C16 Fragment of (+)-Neopeltolide (p NA)
Eduard Hartmann, Martin Oestreich
Published Online: Jul 20 2010 11:23AM
DOI: 10.1002/anie.201002916

	Matched or mismatched, that is not the question! The anti,anti configuration of the C7-C16 fragment of (+)-neopeltolide is stereoselectively installed in an iterative sequence of catalyst-controlled Si group and Me group transfers, even with mismatched selectivity in the former (Si=Me2PhSi, see scheme; TBS=tert-butyldimethylsilyl).

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Asymmetric Catalysis

Catalytic Asymmetric Bromoamination of Chalcones: Highly Efficient Synthesis of Chiral -Bromo--Amino Ketone Derivatives (p NA)
Yunfei Cai, Xiaohua Liu, Yonghai Hui, Jun Jiang, Wentao Wang, Weiliang Chen, Lili Lin, Xiaoming Feng
Published Online: Jul 20 2010 11:23AM
DOI: 10.1002/anie.201002355

	Stand and deliver: The first highly regio- and enantioselective bromoamination of chalcones has been developed which proceeds via an unusual bromonium-based mechanism to deliver the title compounds. Excellent results were obtained using 0.05 mol % of the C2-symmetric N,N-dioxide/scandium(III) complex under mild conditions (see scheme).

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Push-Pull Chromophores

Homoconjugated Push-Pull and Spiro Systems: Intramolecular Charge-Transfer Interactions and Third-Order Optical Nonlinearities (p NA)
Shin-ichiro Kato, Marten T. Roberts Beels, Philip La Porta, W. Bernd Schweizer, Corinne Boudon, Jean-Paul Gisselbrecht, Ivan Biaggio, François Diederich
Published Online: Jul 20 2010 11:23AM
DOI: 10.1002/anie.201002236

	Homoconjugated push-pull chromophores are obtained by [2+2] cycloaddition of 2,3-dichloro-5,6-dicyano-p-benzoquinone to anilino or ferrocene donor-substituted alkynes, and in one case a spiro compound (see picture: examples with corresponding electron adsorption spectra; C gray, Cl green, N blue, O red). Significant third-order optical nonlinearities could be measured for the first time for homoconjugated push-pull systems.

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Self-Assembled Monolayers

Oligomers and Cyclooligomers of Rigid Phenylene-Ethynylene-Butadiynylenes: Synthesis and Self-Assembled Monolayers (p NA)
Stefan-S. Jester, Natalia Shabelina, Stephan M. Le Blanc, Sigurd Höger
Published Online: Jul 20 2010 11:23AM
DOI: 10.1002/anie.201001625

	Starting from the same bisacetylene, different reaction conditions (palladium or copper catalysis) selectively yielded cyclic or acyclic oligomers with n=2-6 (see picture for n=3) linked by freely rotating corner units. STM images of self-assembled monolayers revealed the difference in the adsorption behavior of the acyclic and cyclic oligomers.

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Natural Product Synthesis

Total Synthesis of (-)-Virginiamycin M₂ (p NA)
Jie Wu, James S. Panek
Published Online: Jul 20 2010 4:00AM
DOI: 10.1002/anie.201002220

	Has a nice ring to it: A concise and modular total synthesis of the naturally occurring antibiotic virginiamycin M2 is described. A Barbier-type cyclization was used to close the 23-membered macrocycle and deliver virginiamycin M2 in 19 steps from a chiral organosilane.

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Superhydrophobic Coatings

Bioinspired Self-Healing Superhydrophobic Coatings (p NA)
Yang Li, Long Li, Junqi Sun
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201001258

	Heal thyself! Self-healing superhydrophobic coatings are fabricated by preserving healing agents of reacted fluoroalkylsilane in layered polymeric coatings that are porous and rigidly flexible. When the top layer of fluoroalkyl chains decomposes or the coatings are scratched, the healing agents migrate to the surface to restore the superhydrophobicity of the coatings (see picture).

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Reviews

Designed to Deliver

Polymeric Multilayer Capsules in Drug Delivery (p NA)
Liesbeth J. De Cock, Stefaan De Koker, Bruno G. De Geest, Johan Grooten, Chris Vervaet, Jean Paul Remon, Gleb B. Sukhorukov, Maria N. Antipina
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.200906266

	Layer-by-layer coating of a sacrificial template followed by dissolution of the template can be used to generate polymeric multilayer capsules. By varying the capsule components and their physicochemical properties, multifunctional microcarriers (red circles) can be designed with high potential for drug delivery.

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Highlights

Phosphorus Mononitride

A Different View of Coordination Chemistry: Bis(carbene) Adducts of (PN) and (PN)⁺ (p NA)
Lothar Weber
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201003479

	The taming of the shrew: If the familiar method of stabilizing small reactive molecules in the coordination sphere of transition metal complexes fails, an inverse approach is recommended: Clasp the elusive particle, (PN), with two nucleophilic singlet carbenes and tame it (see mesomeric limiting structures; Dipp=2,6-diisopropylphenyl).

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Lab-on-a-Chip

Screening in One Sweep using the Slipchip (p NA)
Detlev Belder
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201002059

	Slip sliding away: Chemical processes can be executed on microfluidic chips by simply slipping microstructured plates over each other (see picture), like the movement of a valve. This so-called slipchip device requiring no pumps or valves and was successfully applied to high-throughput nanoliter screening for protein crystallography and immunoassays.

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Communications

Total Synthesis

Total Synthesis of Chloptosin (p NA)
Alexander J. Oelke, David J. France, Tatjana Hofmann, Georg Wuitschik, Steven V. Ley
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201002880

	Two is better that one: A new organocatalytic route for the asymmetric preparation of the embedded piperazic acids and a Stille coupling of an ortho-chloropyrroloindole served as key steps in the total synthesis of the dimeric cyclopeptide chloptosin (see structure).

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Iron Catalysis

Enantioselective Synthesis of Amines: General, Efficient Iron-Catalyzed Asymmetric Transfer Hydrogenation of Imines (p NA)
Shaolin Zhou, Steffen Fleischer, Kathrin Junge, Shoubhik Das, Daniele Addis, Matthias Beller
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201002456

	In the iron age: A readily accessible, active iron catalyst serves in the straightforward, catalytic transfer hydrogenation of imines (see scheme). A series of imines are converted to chiral amines in high yields and very good enantioselectivities. This method should find broad application in the search for bioactive chiral amines.

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Natural Products

Total Synthesis of Peloruside A through Kinetic Lactonization and Relay Ring-Closing Metathesis Cyclization Reactions (p NA)
Thomas R. Hoye, Junha Jeon, Lucas C. Kopel, Troy D. Ryba, Manomi A. Tennakoon, Yini Wang
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201002293

	The other side: A convergent total synthesis of peloruside A (1) is described. The key strategic features are a diastereoselective lactonization to generate a C5-C9 valerolactone from the C2-symmetric ketone 3, and a relay ring-closing metathesis reaction to produce a dehydrovalerolactone 2. A new isomer of 1, the valerolactone isopeloruside A (iso-1), was identified. MOM=methoxymethyl.

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Fluorescent Probes

A Significant Improvement of the Efficacy of Radical Oxidant Probes by the Kinetic Isotope Effect (p NA)
Kousik Kundu, Sarah F. Knight, Seungjun Lee, W. Robert Taylor, Niren Murthy
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201002228

	A breath of fresh air: The rate of aerial oxidation of dihydroethidium and hydrocyanine radical oxidant probes can be selectively reduced by deuteration (see picture). The reaction rate between the deuterated compounds and the superoxide radical was reduced by a much smaller factor because of mechanistic differences between the two reactions. The deuterated probes are more effective than their hydrogen analogues in vitro, in cell culture, and in vivo.

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Natural Product Synthesis

Total Synthesis of Dictyodendrin A and B (p NA)
Kentaro Okano, Hideto Fujiwara, Toshiharu Noji, Tohru Fukuyama, Hidetoshi Tokuyama
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201001966

	In-do-line of fire: A highly efficient total synthesis of the title compounds features a novel benzyne-mediated one-pot indoline formation/cross-coupling sequence for the construction of a highly substituted key indoline intermediate. The peripheral substituents were then introduced onto the intermediate in a modular fashion to complete the total syntheses of dictyodendrin A and B.

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Biomimetic Synthesis

Biomimetic Synthesis of (-)-Pycnanthuquinone C through the Diels-Alder Reaction of a Vinyl Quinone (p NA)
Florian Löbermann, Peter Mayer, Dirk Trauner
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201001862

	Three strikes and youre out! A concise, asymmetric synthesis of pycnanthuquinone C underscores the biosynthetic relevance of Diels-Alder reactions of vinyl quinones. The relative and absolute configuration of the natural product has been elucidated.

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Self-Assembly

The Hierarchical Self-Assembly of Charge Nanocarriers: A Highly Cooperative Process Promoted by Visible Light (p NA)
Emilie Moulin, Fréderic Niess, Mounir Maaloum, Eric Buhler, Irina Nyrkova, Nicolas Giuseppone
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201001833

	Let there be more light: Triarylamine-based building blocks respond to visible-light exposure by the formation of cationic radicals that hierarchically self-assemble into molecular wires, which in turn combine within larger fibers (see picture). The stimuli-responsive supramolecular scaffold, which is created by charge transfer and reversibly broken up by heating, prevents the quenching of holes within the wires.

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Enantioselectivity

Enantioselectivity of Haloalkane Dehalogenases and its Modulation by Surface Loop Engineering (p NA)
Zbynek Prokop, Yukari Sato, Jan Brezovsky, Tomas Mozga, Radka Chaloupkova, Tana Koudelakova, Petr Jerabek, Veronika Stepankova, Ryo Natsume, Jan G. E. van Leeuwen, Dick B. Janssen, Jan Florian, Yuji Nagata, Toshiya Senda, Jiri Damborsky
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201001753

	In the loop: Engineering of the surface loop in haloalkane dehalogenases affects their enantiodiscrimination behavior. The temperature dependence of the enantioselectivity (lnE versus 1/T) of -bromoalkanes by haloalkane dehalogenases is reversed (red data points) by deletion of the surface loop; the selectivity switches back when an additional single-point mutation is made. This behavior is not observed for -bromoesters.

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RNA-Aptamers

Expanding the Concept of Chemically Programmable Antibodies to RNA Aptamers: Chemically Programmed Biotherapeutics (p NA)
Ulrich Wuellner, Julia I. Gavrilyuk, Carlos F. Barbas III
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201001736

	Aptamer-programmed antibodies: An RNA aptamer was covalently attached to antibody 38C2 (see scheme) to provide an aptamer-programmed antibody with significantly higher affinity and improved pharmacokinetic properties compared to the parent aptamer. This strategy may provide a promising new class of immunotherapeutics that derive their specificity from nucleic acids.

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Nanoparticle Catalysts

Gold Nanoparticles Embedded in Mesoporous Carbon Nitride Stabilizer for Highly Efficient Three-Component Coupling Reaction (p NA)
K. K. R. Datta, B. V. Subba Reddy, Katsuhiko Ariga, Ajayan Vinu
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201001699

	Support with triple function: Au nanoparticles with sizes of less than 7 nm were fabricated in the channels of a mesoporous carbon nitride (MCN) support, which acts as a stabilizing, size-controlling, and reducing agent (see picture; Au NPs in green). The embedded, well-dispersed Au nanoparticles are a highly active, selective, and recyclable catalyst for the three-component coupling reaction of benzaldehyde, piperidine, and phenylacetylene for the synthesis of propargylamine.

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Phosphorus Chemistry

Preparation of Ligand-Stabilized [P₄O₄]²⁺ by Controlled Hydrolysis of a Janus Head Type Diphosphorus Trication (p NA)
Jan J. Weigand, Kai-Oliver Feldmann, Antje K. C. Echterhoff, Andreas W. Ehlers, Koop Lammertsma
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201001363

	A door to new opportunities: The stepwise hydrolysis of a diphosphorus trication is an efficient method for the preparation of an unusual ligand-stabilized dication that contains a novel cationic [P4O4]2+ framework. This approach demonstrates the potential of the diphosphorus trication as a source for phosphorus building blocks to be used in the construction of novel cationic ring and cluster systems.

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Conjugated Oligomers

A Modular Synthetic Approach to Conjugated Pentacene Di-, Tri-, and Tetramers (p NA)
Dan Lehnherr, Adrian H. Murray, Robert McDonald, Rik R. Tykwinski
Published Online: Jul 19 2010 9:50AM
DOI: 10.1002/anie.201000555

	Mind the band gap: -conjugated pentacene di-, tri-, and tetramers can be synthesized by using a versatile building block in Hay homocoupling as well as Cadiot-Chodkiewicz cross-coupling reactions. This modular approach allows the evaluation of solubility, stability, and the HOMO-LUMO gap as a function of compound length. Long-range 3D overlap occurs in the iBu3Si-substituted pentacene dimer (see figure; n=2).

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Phosphorus Mononitride

Isolation of a Carbene-Stabilized Phosphorus Mononitride and Its Radical Cation (PN^+.) (p NA)
Rei Kinjo, Bruno Donnadieu, Guy Bertrand
Published Online: Jul 15 2010 6:24AM
DOI: 10.1002/anie.201002889

	Carbenes can do better than metals: Phosphorus mononitride transition-metal complexes have never been isolated, but a PN fragment capped by two bulky, strongly electron-releasing singlet carbenes can be prepared at room temperature (see picture; P red, N blue, C gray). The one-electron oxidation produced the corresponding stable radical cation.

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Host-Guest Systems

Technetium-99 MAS NMR Spectroscopy of a Cationic Framework Material that Traps TcO₄^- Ions (p NA)
Ping Yu, Shuao Wang, Evgeny V. Alekseev, Wulf Depmeier, David T. Hobbs, Thomas E. Albrecht-Schmitt, Brian L. Phillips, William H. Casey
Published Online: Jul 15 2010 6:24AM
DOI: 10.1002/anie.201002646

	No chance for technetium: 99Tc magic-angle spinning (MAS) NMR spectra show that TcO4- ions, which are generated by nuclear fission and can contaminate the environment, can be trapped within the channels and cavities of a cationic framework material (see picture). These spectra are among the first 99Tc MAS NMR spectra reported to date, and show that the TcO4- ions can be efficiently removed from simulated nuclear waste solutions.

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Carbon Capture

Carbon Dioxide Capture by Superbase-Derived Protic Ionic Liquids (p NA)
Congmin Wang, Huimin Luo, De-en Jiang, Haoran Li, Sheng Dai
Published Online: Jul 15 2010 6:24AM
DOI: 10.1002/anie.201002641

	CO2 capture: Protic ionic liquids (PILs) from superbase and fluorinated alcohol, imidazole, pyrrolinone, or phenol were designed to capture CO2 based on the reactivity of their anions to CO2. These PILs are capable of rapid and reversible capture of about one equivalent of CO2, which is superior to those sorption systems based on traditional aprotic ILs.

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Cross-Coupling

A General and Special Catalyst for Suzuki-Miyaura Coupling Processes (p NA)
Wenjun Tang, Andrew G. Capacci, Xudong Wei, Wenjie Li, Andre White, Nitinchandra D. Patel, Jolaine Savoie, Joe J. Gao, Sonia Rodriguez, Bo Qu, Nizar Haddad, Bruce Z. Lu, Dhileepkumar Krishnamurthy, Nathan K. Yee, Chris H. Senanayake
Published Online: Jul 15 2010 6:24AM
DOI: 10.1002/anie.201002404

	Biaryl monophosphorus ligands containing a 2,3-dihydrobenzo[d][1,3]oxaphosphole framework are highly effective for the palladium-catalyzed Suzuki-Miyaura cross-coupling reactions of a wide range of substrates. Ligand 1 has demonstrated excellent performance for coupling reactions of extremely hindered arylboronic acids.

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CH Activation

Platinum and Palladium Complexes Containing Cationic Ligands as Catalysts for Arene H/D Exchange and Oxidation (p NA)
Marion H. Emmert, J. Brannon Gary, Janette M. Villalobos, Melanie S. Sanford
Published Online: Jul 15 2010 6:24AM
DOI: 10.1002/anie.201002351

	Cationic catalysts in HD: Palladium(II) and platinum(II) complexes of pyridinium-substituted bipyridine ligands are highly active and stable catalysts for H/D exchange and oxidation of aromatic CH bonds (TONs up to 3200, TOFs up to 0.1 s-1; see scheme, EWG=electron-withdrawing group, EDG=electron-donating group).

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Molecular Gelators

Sugar-Derived Phase-Selective Molecular Gelators as Model Solidifiers for Oil Spills (p NA)
Swapnil R. Jadhav, Praveen Kumar Vemula, Rakesh Kumar, Srinivasa R. Raghavan, George John
Published Online: Jul 15 2010 6:24AM
DOI: 10.1002/anie.201002095

	Mopping up: Phase-selective gelators were synthesized from sugar alcohols using biocatalysis. The gelators exhibited an unprecedented ability to phase-selectively gel only organic liquids including crude-oil fractions in the presence of water at room temperature. Oil can be recovered from the gelled phase by heating and distillation. Thus this class of materials may be useful in recovering oil from spills.

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Self-Assembled Monolayers

Isophthalic Acid: A Basis for Highly Ordered Monolayers (p NA)
Izabela Cebula, Cai Shen, Manfred Buck
Published Online: Jul 15 2010 6:24AM
DOI: 10.1002/anie.201002082

	Standing on their own two feet: Underpotential deposition of Cu on Au(111) yields a surface onto which 1,3-benzenedicarboxylic acid (IPA) and 1,3,5-benzenetricarboxylic acid (TMA) adsorb in a bipodal configuration. Both molecules form highly crystalline isostructural monolayers, thus demonstrating the potential of the IPA moiety as tecton for self-assembled monolayers. A thin film of a Cu-TMA coordination polymer was grown on a patterned TMA monolayer.

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Water Splitting

Quantum Dot Monolayer-Sensitized ZnO Nanowire-Array Photoelectrodes: True Efficiency for Water Splitting (p NA)
Hao Ming Chen, Chih Kai Chen, Yu-Chuan Chang, Chi-Wen Tsai, Ru-Shi Liu, Shu-Fen Hu, Wen-Sheng Chang, Kuei-Hsien Chen
Published Online: Jul 15 2010 6:24AM
DOI: 10.1002/anie.201001827

	A photoconversion efficiency of 1.83 % was observed for a photodevice based on ZnO nanowires sensitized with CdTe quantum dots (QDs; see picture; FTO=F-doped SnO2), which is more than 200 % greater than that of pristine ZnO nanowires. The presence of CdTe QDs on the surface of ZnO nanowires was confirmed by HRTEM and elemental mapping.

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Anion Interactions

The -Accepting Arene HAT(CN)₆ as a Halide Receptor through Charge-Transfer: Multisite Anion Interactions and Self-Assembly in Solution and the Solid-State (p NA)
Helen T. Chifotides, Brandi L. Schottel, Kim R. Dunbar
Published Online: Jul 15 2010 6:24AM
DOI: 10.1002/anie.201001755

	Sensitive molecular scaffold: The exceptional electron-acceptor strength of HAT(CN)6 renders it an excellent colorimetric halide sensor. It engages in multisite anion interactions, namely, both charge-transfer and anion-, in solution and the solid state. The halide ions are the driving elements for the spontaneous self-assembly of the sandwich-like complexes through 2,2-charge transfer contacts.

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Polyoxometalate Chemistry

Zinc(II) Containing -Keggin Sandwich-Type Silicotungstate: Synthesis in Organic Media and Oxidation Catalysis (p NA)
Yuji Kikukawa, Kazuya Yamaguchi, Noritaka Mizuno
Published Online: Jul 15 2010 6:24AM
DOI: 10.1002/anie.201001468

	Zinc in about a cat. Polyoxometalate 1 reacts with Zn2+ ions in acetone to form a novel sandwich-type POM 2 in almost quantitative yield. The H2O2-based oxidation of secondary alcohols with 2 efficiently proceeds, with an activity and chemoselectivity that is very different from those of tungsten-based catalysts including 1 (see scheme; green Zn).

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Sapphyrin Derivatives

Protonation-Induced Formation of a Stable Singlet Biradicaloid Derived from a Modified Sapphyrin Analogue (p NA)
Masatoshi Ishida, Satoru Karasawa, Hidemitsu Uno, Fumito Tani, Yoshinori Naruta
Published Online: Jul 15 2010 6:24AM
DOI: 10.1002/anie.200907350

	Acid does the trick: A novel 1,10-phenanthroline-embedded sapphyrin analogue 1 (see scheme; R=COOEt, Ar= p-tolyl) bearing meso alkylidenyl double bonds has been synthesized. Interestingly, the protonated form of 1 ([13 H]3+) exhibits singlet biradicaloid character.

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Inside Covers of the Week

The Engineering of an Orally Active Conotoxin for the Treatment of Neuropathic Pain (p NA)
Richard J. Clark, Jonas Jensen, Simon T. Nevin, Brid P. Callaghan, David J. Adams, David J. Craik
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201003933

	Sea snails of the Conus genus produce bioactive peptides in their venoms to capture prey, but chemists can re-engineer these peptides for drug-design purposes. In their Communication (DOI: 10.1002/anie.201000620), D. J. Craik and co-workers describe how the chemical cyclization of a peptide from Conus victoriae was used to produce a stable and orally active drug lead that is a potent analgesic in a rat model of neuropathic pain. Image design: David Wilson.

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Discovery, Structure, and Anticancer Activity of an Iridium Complex of Diselenobenzoquinone (p NA)
Hani Amouri, Jamal Moussa, Anna K. Renfrew, Paul J. Dyson, Marie Noelle Rager, Lise-Marie Chamoreau
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201003932

	The first diselenobenzoquinone has been isolated as the stable complex [Cp*Ir(4-C6H4Se2)]; X-ray analysis confirms the structure. H. Amouri and co-workers also describe the anticancer activity of this complex in their Communication (DOI: 10.1002/anie.201002532): the diseleno complex is cytotoxic, with a comparable activity to cisplatin.

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Communications

Polyoxometalate Frameworks

Modular Inorganic Polyoxometalate Frameworks Showing Emergent Properties: Redox Alloys (p NA)
Johannes Thiel, Chris Ritchie, Haralampos N. Miras, Carsten Streb, Scott G. Mitchell, Thomas Boyd, M. Nieves Corella Ochoa, Mali H. Rosnes, Jim McIver, De-Liang Long, Leroy Cronin
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201002672

	Alloy, alloy: A pure cobalt-based Keggin network linked by W-O-Co interactions is alloyed with a pure manganese-based Keggin network, linked by W-O-Mn interactions. These isostructural alloys are solid solutions of the Co and Mn nets. The alloys are prepared by the stoichiometric mixing of the components of each discrete network, leading to a series of single-crystalline mixed transition-metal frameworks with novel redox properties.

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Nanocarbon Chemistry

Photochemical Addition of Ethers to C₆₀: Synthesis of the Simplest [60]Fullerene/Crown Ether Conjugates (p NA)
Manolis D. Tzirakis, Michael Orfanopoulos
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201002285

	Easy crowning for [60]fullerene: The simplest and hitherto elusive C60/crown ether conjugates have been prepared through an effective free-radical approach. This approach includes the activation of the otherwise unreactive -CH bond in a series of structurally diverse mono- or polyethers and sulfides. This facile method provides an expedient entry into a novel class of fullerene-based materials.

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Enzyme Inhibitors

Identification of Thiazolidinones Spiro-Fused to Indolin-2-ones as Potent and Selective Inhibitors of the Mycobacterium tuberculosis Protein Tyrosine Phosphatase B (p NA)
Viktor V. Vintonyak, Karin Warburg, Holger Kruse, Stefan Grimme, Katja Hübel, Daniel Rauh, Herbert Waldmann
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201002138

	The best of 40 000: Detailed structure-activity-relationship studies revealed key structural elements of indolin-2-on-3-spirothiazolidinones (see example) and their appropriate configuration for strong inhibitory activity against the pathophysiologically relevant title protein.

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Synthetic Methods

Efficient Titanium Catalyst for Enantioselective Cyanation of Aldehydes: Cooperative Catalysis (p NA)
Zhipeng Zhang, Zheng Wang, Ruzhou Zhang, Kuiling Ding
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201002127

	Two-in-one: The integration of two salen/TiO units into one molecule allows the enantioselective cyanation of aldehydes to afford the enantioenriched natural or nonnatural cyanohydrin derivatives with turnover numbers of 1960-172 000 and ee values up to 97 % (see scheme). Some of the cyanohydrin derivatives are key intermediates for the synthesis of chiral pharmaceuticals or agrochemicals.

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CH Activation

Constructing Multiply Substituted Arenes Using Sequential Palladium(II)-Catalyzed CH Olefination (p NA)
Keary M. Engle, Dong-Hui Wang, Jin-Quan Yu
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201002077

	A balancing act: Complementary catalytic systems are described, in which the reactivity/selectivity balance in PdII-catalyzed ortho-CH olefination can be modulated to enable sequential CH functionalization for the rapid preparation of 1,2,3-trisubstituted arenes 1. Additionally, a rare example of iterative CH activation, in which a newly installed functional group directs subsequent CH activation has been demonstrated (2).

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Protein Identification

Orthogonal Alkynyl Amino Acid Reporter for Selective Labeling of Bacterial Proteomes during Infection (p NA)
Markus Grammel, Mingzi M. Zhang, Howard C. Hang
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201002050

	Bacterial proteins in the haystack: The alkynyl amino acid reporter AOA (see scheme) can be used to visualize and identify newly synthesized bacterial proteins during Salmonella infection of mammalian cells via the copper(I)-catalyzed azide-alkyne cycloaddition. This technique opens new opportunities for the system-wide analysis of bacterial pathogens.

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Field-Effect Transistors

High-Performance Langmuir-Blodgett Monolayer Transistors with High Responsivity (p NA)
Yang Cao, Zhongming Wei, Song Liu, Lin Gan, Xuefeng Guo, Wei Xu, Michael L. Steigerwald, Zhongfan Liu, Daoben Zhu
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201001683

	Molecular field-effect transistors with bulk-like carrier mobility (as high as 0.04 cm2 V-1 s-1), high on/off current ratios (over 106), and high responsivity are formed by the integration of Langmuir-Blodgett techniques with sophisticated micro/nanofabrication. The transistors are formed from self-assembled uniform monolayers of copper phthalocyanine (CuPc) semiconductors and single-layer graphene as planar contacts.

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Organocatalysis

Mechanistic Complexity in Organo-SOMO Activation (p NA)
James J. Devery III, Jay C. Conrad, David W. C. MacMillan, Robert A. Flowers II
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201001673

	Wet chemistry: Organo-SOMO activation is an intricate process. The catalyst is deactivated in the absence of H2O and its concentration is maintained with 2 equivalents of H2O. The kinetic role of ceric ammonium nitrate (CAN) is masked by phase transfer and its limited solubility is enhanced by added H2O. Mechanistic studies show that careful addition of H2O to dried reagents greatly enhances reaction. TMS=trimethylsilyl.

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Quinone Methides

Dynamic Cross-Linking Is Retained in Duplex DNA after Multiple Exchange of Strands (p NA)
Huan Wang, Steven E. Rokita
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201001597

	Strands may come and go, but cross-linking is forever: Dynamic combinatorial chemistry can respond to changing environments, a characteristic that is now demonstrated with DNA cross-linking based on reversible alkylation of a quinone methide intermediate (see picture).

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Aromatic Fluorination

Synthesis of Aryl Fluorides on a Solid Support and in Solution Utilizing a Fluorinated Solvent (p NA)
Marion Döbele, Sylvia Vanderheiden, Nicole Jung, Stefan Bräse
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201001507

	F for fast: The perfluorinated solvent C6F14 is the key to a new variant of the Balz-Schiemann reaction for the synthesis of fluorinated arenes. Triazenes are converted to fluoroarenes under mild conditions on a support and in solution phase (see scheme). The method is straightforward and inexpensive, and yields previously difficult-to-prepare fluoroarenes in high purity.

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RNA-Ligand Interactions

Highly Modular Structure and Ligand Binding by Conformational Capture in a Minimalistic Riboswitch (p NA)
Elke Duchardt-Ferner, Julia E. Weigand, Oliver Ohlenschläger, Sina R. Schmidtke, Beatrix Suess, Jens Wöhnert
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201001339

	Be prepared: The structure of an synthetic neomycin riboswitch RNA (N1) is investigated by NMR spectroscopy. A largely disordered free structural ensemble also contains a compact conformation that resembles the ligand-bound state thus suggesting a binding mechanism by conformational capture (see scheme, red=ligand).

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Nonnatural Nucleobases

2-Aminopurine Incorporation Perturbs the Dynamics and Structure of DNA (p NA)
André Dallmann, Lars Dehmel, Torben Peters, Clemens Mügge, Christian Griesinger, Jennifer Tuma, Nikolaus P. Ernsting
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201001312

	Vive la petite différence: 2-Aminopurine (2AP) induces small but detectable perturbations of the DNA helix. More significant are changes in the base-pair dynamics in the vicinity of 2AP. The differences have been characterized in NMR and UV spectroscopic studies on a 13-mer DNA double strand with either adenine (A) or 2AP in a central position.

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Analyzing Works of Art

Revealing the sfumato Technique of Leonardo da Vinci by X-Ray Fluorescence Spectroscopy (p NA)
Laurence de Viguerie, Philippe Walter, Eric Laval, Bruno Mottin, V. Armando Solé
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201001116

	Not just a pretty face: Non-invasive X-ray fluorescence spectroscopy was used to reveal the sfumato paint layer stacking method that was used by Leonardo da Vinci to paint the faces in seven of his paintings. A strong diversity in his technique could clearly be seen with this method.

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Sensors

Chromogenic Detection of Nerve Agent Mimics by Mass Transport Control at the Surface of Bifunctionalized Silica Nanoparticles (p NA)
Estela Climent, Almudena Martí, Santiago Royo, Ramón Martínez-Máñez, M. Dolores Marcos, Félix Sancenón, Juan Soto, Ana M. Costero, Salvador Gil, Margarita Parra
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201001088

	Limited access: Silica nanoparticles functionalized with alcohols and thiols are used for the chromofluorogenic detection of nerve agent mimics. In the absence of the mimics, the thiol groups (yellow circles) react with squaraine dyes (blue diamonds) to result in the bleaching of the solution. In the presence of the mimics, the squaraine-thiol reaction is inhibited (see picture; red triangle=hydroxy, empty triangles=silicate, blue circle=nitrogen).

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Monolayers

Nanotexture Switching of Single-Layer Hexagonal Boron Nitride on Rhodium by Intercalation of Hydrogen Atoms (p NA)
Thomas Brugger, Haifeng Ma, Marcella Iannuzzi, Simon Berner, Adolf Winkler, Jürg Hutter, Jürg Osterwalder, Thomas Greber
Published Online: Jul 14 2010 8:59AM
DOI: 10.1002/anie.201001064

	Playing nano-tectonics: The interaction of atomic hydrogen with a single layer of hexagonal boron nitride on rhodium leads to the removal of the h-BN surface corrugation (see picture; blue region: corrugated, orange region: flat). This change of surface texture arises from the intercalation of hydrogen atoms between the h-BN skin and the metal, and can be restored by annealing to about 600 K to expel the hydrogen atoms.

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Covers of the Week

Cooperative Catalytic Reactions Using Organocatalysts and Transition-Metal Catalysts: Enantioselective Alkylation of Propargylic Alcohols with Aldehydes (p NA)
Masahiro Ikeda, Yoshihiro Miyake, Yoshiaki Nishibayashi
Published Online: Jul 13 2010 3:17PM
DOI: 10.1002/anie.201003623

	A transition-metal catalyst and an organocatalyst work cooperatively to mediate the enantioselective propargylic alkylation reaction. This process is described by Y. Nishibayashi and co-workers in their Communication (DOI: 10.1002/anie.201002591). The authors liken the cooperative action of the catalysts to that of chopsticks.

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Communications

Homogeneous catalysis

Cooperative Catalytic Reactions Using Organocatalysts and Transition-Metal Catalysts: Enantioselective Propargylic Alkylation of Propargylic Alcohols with Aldehydes (p NA)
Masahiro Ikeda, Yoshihiro Miyake, Yoshiaki Nishibayashi
Published Online: Jul 13 2010 3:17PM
DOI: 10.1002/anie.201002591

	Working together: The titled reaction proceeds in the presence of a thiolate-bridged diruthenium complex (2) and a secondary amine (1) to give the corresponding propargylic alkylated products in excellent yields as a mixture of two diastereoisomers, each with high enantioselectivity. The two catalysts activate propargylic alcohols and aldehydes, respectively, and cooperatively promote the enantioselective reaction.

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Oxocarbenium Ions

Stereoselective Synthesis of Tertiary Ethers through Geometric Control of Highly Substituted Oxocarbenium Ions (p NA)
Lei Liu, Paul E. Floreancig
Published Online: Jul 13 2010 3:17PM
DOI: 10.1002/anie.201002281

	Fully substituted, fully controlled! The geometries of 1,1-disubstituted oxocarbenium ions and the conformations of oxocarbenium ions that contain a tertiary stereocenter can be predicted based on simple models. These models have been applied to highly stereoselective syntheses of tetrahydropyran derivatives that contain tertiary ethers (see scheme; RL, RS, and RN represent large, small, and nucleophilic groups, respectively).

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Novel Polymerases

Directed Evolution of DNA Polymerases for Next-Generation Sequencing (p NA)
Aaron M. Leconte, Maha P. Patel, Lauryn E. Sass, Peter McInerney, Mirna Jarosz, Li Kung, Jayson L. Bowers, Philip R. Buzby, J. William Efcavitch, Floyd E. Romesberg
Published Online: Jul 13 2010 3:17PM
DOI: 10.1002/anie.201001607

	Speeding evolution: An activity-based phage display method was used to address the title application. A mutant of Taq DNA polymerase was identified (see scheme) that incorporates the fluorophore-labeled dA, dT, dC, and dG substrates 50 to 400-fold more efficiently into scarred primers in solution and that also demonstrates significantly improved performance under actual sequencing conditions.

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Biomarker detection

Ratiometric Fluorescent Detection of an Anthrax Biomarker at Molecular Printboards (p NA)
M. Deniz Yilmaz, Shu-Han Hsu, David N. Reinhoudt, Aldrik H. Velders, Jurriaan Huskens
Published Online: Jul 13 2010 3:17PM
DOI: 10.1002/anie.201000540

	Sense and sense ability: A novel surface-assisted fluorescent sensing system is developed for the ratiometric detection of the anthrax biomarker dipicolinic acid (DPA, black, see picture) on a molecular printboard. The system affords a nanomolar sensitivity and high selectivity towards DPA.

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Natural Products

A Convergent Route to the Galbulimima Alkaloids (-)-GB 13 and (+)-GB 16 (p NA)
Weiwei Zi, Shouyun Yu, Dawei Ma
Published Online: Jul 13 2010 1:25AM
DOI: 10.1002/anie.201002299

	Alkaloids all round: A 19-step total synthesis of the galbulimima alkaloid (-)-GB 13 starting from commercially available starting material and the first total synthesis of the galbulimima alkaloid (+)-GB 16 have been achieved (see scheme; Boc=tert-butoxycarbonyl).

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Surface Chemistry

Phototunable Diarylethene Microcrystalline Surfaces: Lotus and Petal Effects upon Wetting (p NA)
Kingo Uchida, Naoki Nishikawa, Norikazu Izumi, Seiji Yamazoe, Hiroyuki Mayama, Yuko Kojima, Satoshi Yokojima, Shinichiro Nakamura, Kaoru Tsujii, Masahiro Irie
Published Online: Jul 13 2010 1:25AM
DOI: 10.1002/anie.201000793

	Dont get wet! The UV irradiation of a photochromic diarylethene microcrystalline film and its subsequent temperature treatment leads to the formation of water-repellant surfaces with different microstrucures. Depending on the microstructure, a water droplet will either roll off the surface (lotus effect) or stay pinned to it (petal effect; see picture).

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Natural Product Synthesis

Asymmetric Total Synthesis of Cylindrocyclophanes A and F through Cyclodimerization and a Ramberg-Bäcklund Reaction (p NA)
K. C. Nicolaou, Ya-Ping Sun, Henry Korman, David Sarlah
Published Online: Jul 12 2010 1:59AM
DOI: 10.1002/anie.201003500

	Two make a cycle: A Ramberg-Bäcklund reaction was employed to form the macrocyclic carbon skeleton of the marine natural products cylindrocyclophanes A and F in an asymmetric synthesis through a head-to-tail dimerization approach (see scheme).

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BO Cyclization

Cyclodimerization of an Oxoboryl Complex Induced by trans Ligand Abstraction (p NA)
Holger Braunschweig, Krzysztof Radacki, Achim Schneider
Published Online: Jul 12 2010 1:59AM
DOI: 10.1002/anie.201002300

	After the scattering comes the gathering: Abstracting the bromide ligand from the novel oxoboryl complex trans-[(Cy3P)2BrPt(BO)] has dramatic consequences: instant cyclodimerization takes place, yielding an ionic compound. The cation has an unprecedented bridging dioxodiboretanediyl ligand (see picture).

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Cluster Compounds

Metathesis Reaction of Hydrocarbyl Ligands across the Triruthenium Plane (p NA)
Atsushi Tahara, Mana Kajigaya, Makoto Moriya, Toshiro Takao, Hiroharu Suzuki
Published Online: Jul 12 2010 1:59AM
DOI: 10.1002/anie.201002235

	Trains and boats and planes: The thermolysis of a triruthenium complex having 3-pentylidyne and 3-pentyne ligands on each face of the trimetallic plane exclusively afforded 3-ethylidyne-3-octyne complex. In this reaction, a C3 fragment migrated from one face of the Ru3 plane to the other. This corresponds to the selective redistribution of two C5 molecules into C2 and C8 molecules.

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DNA Structures

DNA and RNA in Anhydrous Media: Duplex, Triplex, and G-Quadruplex Secondary Structures in a Deep Eutectic Solvent (p NA)
Irena Mamajanov, Aaron E. Engelhart, Heather D. Bean, Nicholas V. Hud
Published Online: Jul 12 2010 1:59AM
DOI: 10.1002/anie.201001561

	Hold the water! Deep-eutectic solvents (DESs) are nonvolatile media suitable for a wide range of chemical reactions. The discovery that nucleic acids can form duplex, triplex, and G-quadruplex structures (which in some cases differ from those adopted in aqueous media) in a water-free DES (see picture) opens the enticing possibility that catalytic nucleic acids and enzyme-nucleic acid complexes could also be used in these solvents.

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DNA Analysis

Analysis of Short Tandem Repeats by using SERS Monitoring and Electrochemical Melting (p NA)
Damion K. Corrigan, Nittaya Gale, Tom Brown, Philip N. Bartlett
Published Online: Jul 12 2010 1:59AM
DOI: 10.1002/anie.201001389

	Take-away: Electrochemical melting with SERS detection on nanostructured electrodes was utilized to discriminate between DNA sequences with different numbers of the GATA short tandem repeat sequence (see diagram). The technique has unique advantages for incorporation into a field-operable DNA analysis device.

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Surface Chemistry

Real Space Investigation of Non-adiabatic CO₂ Synthesis (p NA)
Heiko Gawronski, Michael Mehlhorn, Karina Morgenstern
Published Online: Jul 12 2010 1:59AM
DOI: 10.1002/anie.201001262

	Cannonball run: Preparation of CO2 has been achieved with CO and O2 coadsorbed onto a Cu(111) surface by illumination with laser light at 40 fs-400 nm pulses. The hot-adatom mechanism that follows O2 dissociation leads to a cannonball trajectory of the product molecules and thus escape of CO2 from the reactant site to the bare terrace (see figure). It was thus demonstrated that non-adiabatic heterogeneous catalysis may be followed in real space.

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Inside Covers of the Week

Photocatalytic Aerobic Oxidation of Alcohols on TiO₂: The Acceleration Effect of a Brønsted Acid (p NA)
Qi Wang, Miao Zhang, Chuncheng Chen, Wanhong Ma, Jincai Zhao
Published Online: Jul 7 2010 8:38AM
DOI: 10.1002/anie.201003621

	The acceleration effect of a Brønsted acid was identified in the photocatalytic oxidation of alcohols using TiO2. In their Communication (DOI: 10.1002/anie.201001533) J. Zhao and co-workers show that the acid adsorbed onto the catalyst surface promotes the decomposition of the Ti/H2O2 species to regenerate active sites for the oxidation.

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Highlights

Asymmetric Catalysis

Enantioselective Palladium-Catalyzed Direct Alkylation and Olefination Reaction of Simple Arenes (p NA)
Hong Mei Peng, Li-Xin Dai, Shu-Li You
Published Online: Jul 7 2010 8:38AM
DOI: 10.1002/anie.201000799

	Easy as pie: Simple amino acid derivatives and phosphoramidites assist palladium in the enantioselective direct alkylation and olefination of simple arenes (see scheme; Boc=tert-butoxycarbonyl, Tf=trifluoromethanesulfonyl). Under mild reaction conditions, a practical level of enantiomeric excess was obtained.

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Communications

Heterogeneous Catalysis

Photocatalytic Aerobic Oxidation of Alcohols on TiO₂: The Acceleration Effect of a Brønsted Acid (p NA)
Qi Wang, Miao Zhang, Chuncheng Chen, Wanhong Ma, Jincai Zhao
Published Online: Jul 7 2010 8:38AM
DOI: 10.1002/anie.201001533

	Up to speed: Brønsted acids adsorbed onto TiO2 dramatically accelerated the photocatalytic oxidation of alcohols without any loss of selectivity (see scheme). This effect results from the decomposition of the Ti species, having a side-on peroxide, on the TiO2 surface. The decomposition is aided by the Brønsted acid, thereby regenerating the active Ti sites on the surface of the catalyst.

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Drug Delivery

Probing the Kinetics of Short-Distance Drug Release from Nanocarriers to Nanoacceptors (p NA)
Hong Wang, Jun Xu, Jinghao Wang, Tao Chen, Yong Wang, Yan Wen Tan, Haibin Su, Khai Leok Chan, Hongyu Chen
Published Online: Jul 7 2010 8:38AM
DOI: 10.1002/anie.201001065

	Quick release: Polymer-coated gold nanoparticles (AuNPs) are used as nanocarriers and nanoscale acceptors are used to represent proteins and lipid membranes in a model drug-delivery system. The fluorescence of a drug is quenched in the vicinity of the AuNPs but reemerges upon its release (see picture). The critical role of nanoacceptors in facilitating drug release is demonstrated.

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Catanionic Tubules

Catanionic Tubules with Tunable Charge (p NA)
Nicola Manghisi, Claudia Leggio, Aida Jover, Francisco Meijide, Nicolae Viorel Pavel, Victor H. Soto Tellini, José Vázquez Tato, Raffaele G. Agostino, Luciano Galantini
Published Online: Jul 7 2010 8:38AM
DOI: 10.1002/anie.201000951

	Balancing the positives and negatives: A new behavior in the field of catanionic mixtures was observed in solutions of anionic and cationic forms of rigid non-conventional amphiphiles. Dilute aqueous mixtures of anionic and cationic bile salt derivatives form catanionic tubules with charge ranging from negative to positive values depending on the surfactant molar ratio of the mixtures.

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Time-Resolved Spectroscopy

Picosecond Time-Resolved X-Ray Emission Spectroscopy: Ultrafast Spin-State Determination in an Iron Complex (p NA)
György Vankó, Pieter Glatzel, Van-Thai Pham, Rafael Abela, Daniel Grolimund, Camelia N. Borca, Steven L. Johnson, Christopher J. Milne, Christian Bressler
Published Online: Jul 7 2010 8:38AM
DOI: 10.1002/anie.201000844

	Ultrafast spin probe: A short-lived transient species of light-excited [Fe(bpy)3]2+ (bpy=2,2-bipyridine) shows geometry variations that correspond to excitation to a high-spin state, in which the spin momentum of FeII has now been directly determined to be S=2 by spin-sensitive ultrafast X-ray emission spectroscopy.

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Inside Covers of the Week

Monolithic and Flexible Polyimide Film Microreactors for Organic Microchemical Applications Fabricated by Laser Ablation (p NA)
Kyoung-Ik Min, Tae-Ho Lee, Chan Pil Park, Zhi-Yong Wu, Hubert H. Girault, Ilhyong Ryu, Takahide Fukuyama, Yu Mukai, Dong-Pyo Kim
Published Online: Jul 2 2010 11:35AM
DOI: 10.1002/anie.201003239

	A monolithic and flexible polyimide film microreactor with passive mixing patterns is fabricated by laser ablation. In their Communication (DOI: 10.1002/anie.201002004). D. P. Kim and co-workers show the excellent stability of these film microreactors by using them to perform various organic synthesis reactions under harsh conditions. The simple fabrication and the facile adhesive sealing step facilitate mass production of this flexible film microfluidic device.

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Graphene Oxide: A Convenient Carbocatalyst for Facilitating Oxidation and Hydration Reactions (p NA)
Daniel R. Dreyer, Hong-Peng Jia, Christopher W. Bielawski
Published Online: Jul 2 2010 11:35AM
DOI: 10.1002/anie.201003238

	Carbocatalysis - the intersection of carbon and catalysis - is the use of large-area, metal-free carbon to facilitate chemical reactions. In their Communication (DOI: 10.1002/anie.201002160), C. Bielawski and co-workers demonstrate that graphene-based materials may be used as carbocatalysts to facilitate a number of synthetically useful transformations, including the oxidation of alcohols and alkenes into their respective aldehydes and ketones, as well as the hydration of alkynes.

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Communications

Coordination Polymers

Control of Interpenetration for Tuning Structural Flexibility Influences Sorption Properties (p NA)
Sareeya Bureekaew, Hiroshi Sato, Ryotaro Matsuda, Yoshiki Kubota, Raita Hirose, Jungeun Kim, Kenichi Kato, Masaki Takata, Susumu Kitagawa
Published Online: Jul 2 2010 11:35AM
DOI: 10.1002/anie.201002259

	Transforming jungle gyms: Structural flexibility and sorption behavior can be tuned by controlling the degree of interpenetration of 3D porous coordination polymers (PCPs). The architectural connectivity of PCPs, even those that are composed of the same chemical components, has a significant impact on the structural flexibility and sorption behavior, which was confirmed by coincident XRPD/adsorption measurements.

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Carbocatalysis

Graphene Oxide: A Convenient Carbocatalyst for Facilitating Oxidation and Hydration Reactions (p NA)
Daniel R. Dreyer, Hong-Peng Jia, Christopher W. Bielawski
Published Online: Jul 2 2010 11:35AM
DOI: 10.1002/anie.201002160

	Do not pass GO: Graphene oxide (GO) catalyzes the oxidation of various alcohols and alkenes, and the hydration of various alkynes into their respective aldehydes and ketones in good to excellent yields. The reactions proceed under relatively mild conditions and simple filtration was shown to be a convenient and effective method of catalyst recovery.

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Hydrogen Bonding

Dispersion-Driven Hydrogen Bonding: Predicted Hydrogen Bond between Water and Platinum(II) Identified by Neutron Diffraction (p NA)
Silvia Rizzato, Jacqueline Bergès, Sax A. Mason, Alberto Albinati, Jií Kozelka
Published Online: Jul 2 2010 11:35AM
DOI: 10.1002/anie.201001892

	An alternative to classical? In square-planar d8 complexes the metal ion can interact with axial H2O molecules either as a Lewis acid or as a Lewis base. Ab initio calculations predicted that uncharged PtII complexes form a hydrogen-bond-like interaction with H2O, in which PtII acts as a Lewis base. Such a nonclassical OHPt hydrogen bond has now been identified in crystals of trans-[PtCl2(NH3)(N-glycine)]H2O by neutron diffraction.

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Imaging Mass Spectrometry

Discrimination of Human Astrocytoma Subtypes by Lipid Analysis using Desorption Electrospray Ionization Imaging Mass Spectrometry (p NA)
Livia S. Eberlin, Allison L. Dill, Alexandra J. Golby, Keith L. Ligon, Justin M. Wiseman, R. Graham Cooks, Nathalie Y. R. Agar
Published Online: Jul 2 2010 11:35AM
DOI: 10.1002/anie.201001452

	Differentiation of human brain astrocytic tumor grades can be achieved by direct lipid analysis using desorption electrospray ionization mass spectrometry (DESI-MS). Distinctive lipid profiles are associated with degree of malignancy, grades II, III, and IV (see picture).

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Quinone Complexes

Discovery, Structure, and Anticancer Activity of an Iridium Complex of Diselenobenzoquinone (p NA)
Hani Amouri, Jamal Moussa, Anna K. Renfrew, Paul J. Dyson, Marie Noelle Rager, Lise-Marie Chamoreau
Published Online: Jul 2 2010 11:35AM
DOI: 10.1002/anie.201002532

	Caught in the act: The first stable 4-diseleno-p-benzoquinone complex, [Cp*Ir(4-C6H4Se2)], has been isolated. The X-ray molecular structure (see picture; Ir magenta, Se yellow) confirms the coordination of the elusive diselenobenzoquinone intermediate. The anticancer activity of this complex was compared to related oxygen and sulfur analogues; only the diseleno complex was cytotoxic, with a comparable activity to cisplatin.

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Mismatched Base Pairing

Incorporation of Thymine Nucleotides by DNA Polymerases through T-Hg^II-T Base Pairing (p NA)
Hidehito Urata, Eriko Yamaguchi, Tatsuya Funai, Yuriko Matsumura, Shun-ichi Wada
Published Online: Jul 2 2010 11:35AM
DOI: 10.1002/anie.201002142

	A dangerous matchmaker: In the presence of HgII ions, DNA polymerases incorporated thymidine 5-triphosphate (TTP) at the site opposite thymine in a template strand and made a phosphodiester bond to elongate the primer strand. This unusual metal-mediated base pair was recognized by the DNA polymerases, which went on to synthesize the full-length product (see picture).

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Direct Cross-Coupling

Facile Palladium-Catalyzed Arylation of Heterocycles and Nonactivated Arenes with Aryl Chlorides (p NA)
Jan Pschierer, Herbert Plenio
Published Online: Jul 2 2010 11:35AM
DOI: 10.1002/anie.201002045

	Efficient CH/CX activation in water: Arenes or various heterocycles were treated with aryl chlorides and gave the respective biaryl compounds in more than 90 % yield using 0.05-5 mol % of a Pd/phosphine complex in water or water/n-butanol as the reaction solvent (see scheme; Cy=cyclohexyl).

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Total Synthesis

An Enantioselective Total Synthesis of (+)-Peloruside A (p NA)
Meredeth A. McGowan, Christian P. Stevenson, Matthew A. Schiffler, Eric N. Jacobsen
Published Online: Jun 28 2010 2:07PM
DOI: 10.1002/anie.201002177

	Short and sweet: Chiral epoxides, prepared using (salen)cobalt-catalyzed ring-opening reactions, and a chromium catalyst controlled hetero-Diels-Alder reaction were used to set most of the stereocenters in the total synthesis of the microtubule-stabilizing agent peloruside A. The overall highly convergent route required only 20 steps in the longest linear sequence. MOM=methoxymethyl, TBS=tert-butyldimethylsilyl.

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Minireviews

Pummerer Chemistry

Beyond the Pummerer Reaction: Recent Developments in Thionium Ion Chemistry (p NA)
Laura H. S. Smith, Susannah C. Coote, Helen F. Sneddon, David J. Procter
Published Online: Jun 25 2010 9:56AM
DOI: 10.1002/anie.201000517

	Thionium ions have assumed great importance as electrophiles in organic chemistry in recent years. From classical Pummerer reactions to extended and connective variants, these versatile reactive intermediates have found applications in the synthesis of a wide range of compounds including alkaloids, nucleoside derivatives, and heterocycles.

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Communications

RNA Modification

The AlkB Domain of Mammalian ABH8 Catalyzes Hydroxylation of 5-Methoxycarbonylmethyluridine at the Wobble Position of tRNA (p NA)
Ye Fu, Qing Dai, Wen Zhang, Jin Ren, Tao Pan, Chuan He
Published Online: Jun 25 2010 9:56AM
DOI: 10.1002/anie.201001242

	Family ties: The AlkB family of nonheme iron, -ketoglutarate (KG)-dependent dioxygenases is involved in biological processes such as DNA/RNA repair and obesity. The AlkB domain of ABH8 is shown to catalyze the hydroxylation of a modified uridine (mcm5U) into (S)-mchm5U at the wobble position of the anticodon stem-loop in tRNA (see scheme), thereby suggesting that this protein is a tRNA hypermodification enzyme.

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Microreactors

Monolithic and Flexible Polyimide Film Microreactors for Organic Microchemical Applications Fabricated by Laser Ablation (p NA)
Kyoung-Ik Min, Tae-Ho Lee, Chan Pil Park, Zhi-Yong Wu, Hubert H. Girault, Ilhyong Ryu, Takahide Fukuyama, Yu Mukai, Dong-Pyo Kim
Published Online: Jun 23 2010 12:56PM
DOI: 10.1002/anie.201002004

	Keeping limber: A monolithic and flexible polyimide film microreactor is introduced for organic reactions and syntheses. Unlike glass microreactors, it is easy to fabricate, yet it is inert to solvents and acids under harsh conditions, unlike other polymer microreactors.

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Organoberyllium Chemistry

Bis(1,3-trimethylsilylallyl)beryllium (p NA)
Stephen C. Chmely, Timothy P. Hanusa, William W. Brennessel
Published Online: Jun 23 2010 12:56PM
DOI: 10.1002/anie.201001866

	Shape-shifter: The beryllium allyl complex [Be{1,3-(SiMe3)2C3H3}2(Et2O)] (see picture) has been synthesized and its X-ray structure determined. Although the allyl ligands are -bonded, the molecule is fluxional in solution, and it engages in a Schlenk equilibrium with BeCl2. DFT calculations suggest that in the absence of a coordinated base, both - and -bound forms would be potential energy minima.

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Actinide Chemistry

[An(H₂O)₉](CF₃SO₃)₃ (An=U-Cm, Cf): Exploring Their Stability, Structural Chemistry, and Magnetic Behavior by Experiment and Theory (p NA)
Christos Apostolidis, Bernd Schimmelpfennig, Nicola Magnani, Patric Lindqvist-Reis, Olaf Walter, Richard Sykora, Alfred Morgenstern, Eric Colineau, Roberto Caciuffo, Reinhardt Klenze, Richard G. Haire, Jean Rebizant, Frank Bruchertseifer, Thomas Fanghänel
Published Online: Jun 23 2010 12:56PM
DOI: 10.1002/anie.201001077

	Lanthanide-like: X-ray diffraction and density functional theory studies show that [An(H2O)9]3+ ions of the actinides U3+-Cf3+ in crystals of their triflate salts have the same structure and electrostatic bonding as their lanthanide counterparts La3+-Eu3+. Moreover, the nine-coordinate geometry is essentially preserved in solution for the lighter elements (see picture).

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Inside Covers of the Week

Reaction of Singlet Dioxygen with Phosphine-Borane Derivatives: From Transient Phosphine Peroxides to Crystalline Peroxoboronates (p NA)
Susana Porcel, Ghenwa Bouhadir, Nathalie Saffon, Laurent Maron, Didier Bourissou
Published Online: Jun 22 2010 7:59AM
DOI: 10.1002/anie.201003227

	Ambiphilic phosphine-boronates readily split singlet dioxygen under mild conditions. As described by D. Bourissou and co-workers in their Communication (DOI: 10.1002/anie.201000520), the initially formed phosphine peroxides spontaneously rearrange into stable crystalline peroxoboronates. Artwork: Christian Pradel.

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Reviews

Reactions in Microdroplets

Microdroplets in Microfluidics: An Evolving Platform for Discoveries in Chemistry and Biology (p NA)
Ashleigh B. Theberge, Fabienne Courtois, Yolanda Schaerli, Martin Fischlechner, Chris Abell, Florian Hollfelder, Wilhelm T. S. Huck
Published Online: Jun 22 2010 1:28AM
DOI: 10.1002/anie.200906653

	More than a drop in the ocean: Microdroplets in microfluidics has become a fast moving research area that is rapidly being established as a powerful tool for performing complex chemical and biological experiments (see picture). This Review assesses the technological challenges as well as the huge benefits compartmentalization, monodispersity, single-molecule sensitivity, and high throughput can bring to biology and chemistry.

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Communications

Surface Structure Elucidation

Real-Space Observation of Surface Termination of a Complex Metal Oxide Catalyst (p NA)
Wei Zhang, Annette Trunschke, Robert Schlögl, Dangsheng Su
Published Online: Jun 22 2010 1:28AM
DOI: 10.1002/anie.201000910

	Looking good: High-resolution TEM can be used to determine the surface structure of a metal oxide catalyst in real space. The picture shows HR-TEM images of one catalyst particle along 001 direction far from Scherzer focus. The perimeter of the particle is highlighted by the fractured structural units.

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Singlet Dioxygen Fixation

Reaction of Singlet Dioxygen with Phosphine-Borane Derivatives: From Transient Phosphine Peroxides to Crystalline Peroxoboronates (p NA)
Susana Porcel, Ghenwa Bouhadir, Nathalie Saffon, Laurent Maron, Didier Bourissou
Published Online: Jun 22 2010 1:28AM
DOI: 10.1002/anie.201000520

	Singlet dioxygen is readily split by phosphine-boronates under mild conditions. The initially formed phosphine peroxides spontaneously rearrange by BO migration. The resulting peroxoboronates have been structurally characterized, and their ability to undergo oxygen transfer reactions substantiated.

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Inside Covers of the Week

Innovative Inorganic-Organic Nanohybrid Materials: Coupling Quantum Dots to Carbon Nanotubes (p NA)
Christian Schulz-Drost, Vito Sgobba, Christina Gerhards, Susanne Leubner, Rafael M. Krick Calderon, Andrés Ruland, Dirk M. Guldi
Published Online: Jun 22 2010 1:28AM
DOI: 10.1002/anie.201003293

	Photoactive inorganic-organic nanohybrids were constructed from CdTe quantum dots (QDs) and single-walled carbon nanotubes (SWNTs). In their Communication (DOI: 10.1002/anie.200906891), D. M. Guldi and co-workers report that the introduction of surface stabilizers to QDs facilitates both the covalent attachment of a pyrene group and the anchoring onto the SWNTs. Complementary luminescence and ultrafast transient absorption analyses indicate the formation of a charge-separated state; this paves the way for the successful integration into photovoltaic devices.

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Controlled Reducibility of a Metal-Organic Framework with Coordinatively Unsaturated Sites for Preferential Gas Sorption (p NA)
Ji Woong Yoon, You-Kyong Seo, Young Kyu Hwang, Jong-San Chang, Hervé Leclerc, Stefan Wuttke, Philippe Bazin, Alexandre Vimont, Marco Daturi, Emily Bloch, Philip L. Llewellyn, Christian Serre, Patricia Horcajada, Jean-Marc Grenèche, Alirio E. Rodrigues, Gérard Férey
Published Online: Jun 22 2010 1:28AM
DOI: 10.1002/anie.201003292

	The controlled reducibility of coordinatively unsaturated iron sites in MIL-100(Fe), [Fe3O(H2O)2F0.81(OH)0.19{C6H3(CO2)3}2]14.5 H2O, is described by J.-S. Chang and co-workers in their Communication (DOI: 10.1002/anie.201001230). Thermal activation of MIL-100(Fe) generates coordinatively unsaturated sites with mixed-valence FeII/FeIII, leading to preferential sorption selectivity towards unsaturated gas molecules such as propylene.

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Covers of the Week

Expanding the Scope of Metal-Free Catalytic Hydrogenation through Frustrated Lewis Pair Design (p NA)
Gábor Ers, Hasan Mehdi, Imre Pápai, Tibor András Rokob, Péter Király, Gábor Tárkányi, Tibor Soós
Published Online: Jun 22 2010 1:28AM
DOI: 10.1002/anie.201003339

	The evolution of deep and shallow flowers is a response to a race with pollinating organisms that determines the length and form of the bill of hummingbirds. Likewise, the selection of the Lewis basic component for a frustrated Lewis pair is dictated by the steric congestion around the boron center of the Lewis acid. In their Communication (DOI: 10.1002/anie.201001518), T. Soós and co-workers show that this selection phenomenon can be exploited as a design concept for metal-free hydrogenation catalysts.

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[An(H₂O)₉](CF₃SO₃)₃ (An=U-Cm, Cf): Exploring Their Stability, Structural Chemistry, and Magnetic Behavior by Experiment and Theory (p NA)
Christos Apostolidis, Bernd Schimmelpfennig, Nicola Magnani, Patric Lindqvist-Reis, Olaf Walter, Richard Sykora, Alfred Morgenstern, Eric Colineau, Roberto Caciuffo, Reinhardt Klenze, Richard G. Haire, Jean Rebizant, Frank Bruchertseifer, Thomas Fanghänel
Published Online: Jun 22 2010 1:28AM
DOI: 10.1002/anie.201003226

	Easily prepared and highly soluble actinide(III) salts are of great interest as precursors for actinide complex chemistry. In their Communication (DOI: 10.1002/anie.201001077) P. Lindqvist-Reis and co-workers report how [An(H2O)9]3+(CF3SO3)3 (An=U-Cm, Cf) species can be obtained directly from aqueous solution, a remarkable result for the UIII and NpIII salts given their extremely oxidation-sensitive nature. They also discuss the use of these salts as models for hydrated An3+ ions in solution.

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Communications

Gas Sorption

Controlled Reducibility of a Metal-Organic Framework with Coordinatively Unsaturated Sites for Preferential Gas Sorption (p NA)
Ji Woong Yoon, You-Kyong Seo, Young Kyu Hwang, Jong-San Chang, Hervé Leclerc, Stefan Wuttke, Philippe Bazin, Alexandre Vimont, Marco Daturi, Emily Bloch, Philip L. Llewellyn, Christian Serre, Patricia Horcajada, Jean-Marc Grenèche, Alirio E. Rodrigues, Gérard Férey
Published Online: Jun 16 2010 1:38AM
DOI: 10.1002/anie.201001230

	Gas grabber: Reduction of the porous metal-organic framework MIL-100(Fe) (see picture; X-: OH- or F-; red: O of trimesate ligands) to form coordinatively unsaturated sites at iron(II) (depicted as a violet circle) is essential for selective gas purification or the selective removal of unsaturated gas impurities.

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Hydrogen Activation

Expanding the Scope of Metal-Free Catalytic Hydrogenation through Frustrated Lewis Pair Design (p NA)
Gábor Ers, Hasan Mehdi, Imre Pápai, Tibor András Rokob, Péter Király, Gábor Tárkányi, Tibor Soós
Published Online: Jun 14 2010 6:04AM
DOI: 10.1002/anie.201001518

	No metal causes frustration: Based on a conceptual framework, novel frustrated Lewis acid-base catalyst systems with orthogonal reactivity have been developed. Aside from enhanced functional-group tolerance, unique chemoselectivity can be achieved in catalytic metal-free hydrogenations (see scheme).

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Photoactive Devices

Innovative Inorganic-Organic Nanohybrid Materials: Coupling Quantum Dots to Carbon Nanotubes (p NA)
Christian Schulz-Drost, Vito Sgobba, Christina Gerhards, Susanne Leubner, Rafael M. Krick Calderon, Andrés Ruland, Dirk M. Guldi
Published Online: Jun 10 2010 1:33AM
DOI: 10.1002/anie.200906891

	Inorganic meets organic: Covalent bonds (peptide condensation) and noncovalent interactions (- stacking) have been employed en route toward versatile donor-acceptor inorganic-organic nanohybrids, QD-pyrene/SWNT. A charge-transfer event within the hybrid transforms the excitonic state of the quantum dot into a charge-transfer state that has a lifetime of several nanoseconds.

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Pain Relief Drugs

The Engineering of an Orally Active Conotoxin for the Treatment of Neuropathic Pain (p NA)
Richard J. Clark, Jonas Jensen, Simon T. Nevin, Brid P. Callaghan, David J. Adams, David J. Craik
Published Online: Jun 8 2010 2:49AM
DOI: 10.1002/anie.201000620

	From killers to curers: Peptides from cone snail venoms are potential therapeutic agents for the treatment of neuropathic pain. Unfortunately, these peptides suffer from the disadvantage of short biological half-lives and poor activity when taken orally. A new orally active conotoxin was developed to solve these problems.

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Highlights

Phthalide Synthesis

Catalytic Intramolecular Ketone Hydroacylation: Enantioselective Synthesis of Phthalides (p NA)
Michael C. Willis
Published Online: May 20 2010 12:17PM
DOI: 10.1002/anie.201000159

	Controlling carbonyl groups: Identification of the correct ligand/counterion combination was essential to allow the efficient and selective rhodium-catalyzed conversion of a series of ketobenzaldehydes into the corresponding phthalides using the title reaction (see scheme; cod=cycloocta-l,5-diene).

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Covers of the Week

A Recyclable Nanoparticle-Supported Palladium Catalyst for the Hydroxycarbonylation of Aryl Halides in Water (p NA)
Sebastian Wittmann, Alexander Schätz, Robert N. Grass, Wendelin J. Stark, Oliver Reiser
Published Online: Feb 19 2010 12:15PM
DOI: 10.1002/anie.200000369

	Temperature-dependent reversible immobilization of Pd catalysts on carbon-coated, magnetic Co nanoparticles is facilited by pyrene-modified N-heterocyclic carbene ligands. O. Reiser et al. show in their Communication (DOI: 10.1002/anie.20096166) how this approach allows the efficient palladium-catalyzed carboxlyation of aryl halides in water at 100 °C: In each of 16 cycles the catalyst is recovered by immobilization on the nanoparticles after cooling to room temperature. The nanoparticles are then separated from the mixture by magnetic decantation.

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