Angewandte Chemie International Edition

Cover image for Vol. 53 Issue 48

Editor: Peter Gölitz, Deputy Editors: Neville Compton, Haymo Ross

Online ISSN: 1521-3773

Associated Title(s): Angewandte Chemie, Chemistry - A European Journal, Chemistry – An Asian Journal, ChemistryOpen, ChemPlusChem, Zeitschrift für Chemie

Upcoming Hot Papers

Hot Papers are chosen by the Editors for their importance in a rapidly evolving field of high current interest. Many of the "Very Important Papers" (VIPs) would certainly qualify to be included here, but such a duplication is avoided.

Medicinal Chemistry

Design and Synthesis of High-Affinity Dimeric Inhibitors Targeting the Interactions between Gephyrin and Inhibitory Neurotransmitter Receptors

Dr. Hans Michael Maric, Vikram Babu Kasaragod, Dr. Linda Haugaard-Kedström, Dr. Torben Johann Hausrat, Prof. Dr. Matthias Kneussel, Prof. Dr. Hermann Schindelin and Prof. Dr. Kristian Strømgaard

Design and Synthesis of High-Affinity Dimeric Inhibitors Targeting the Interactions between Gephyrin and Inhibitory Neurotransmitter ReceptorsDouble-teaming: Dimeric peptide ligands were developed that target gephyrin, the central scaffolding protein for inhibitory neurotransmitter receptors in the brain, with unprecedented high affinity. Dimerization also substantially improved the serum stability, thus providing compounds with great promise for further studies of gephyrin–receptor interactions. The X-ray structure shows one of these peptides in complex with two monomers of the gephyrin E domain.

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Asymmetric Dearomatization

Asymmetric Dearomatization of β-Naphthols through an Amination Reaction Catalyzed by a Chiral Phosphoric Acid

Shou-Guo Wang, Dr. Qin Yin, Dr. Chun-Xiang Zhuo and Prof. Dr. Shu-Li You

Asymmetric Dearomatization of β-Naphthols through an Amination Reaction Catalyzed by a Chiral Phosphoric AcidUseful skeletons: An electrophilic amination reaction catalyzed by chiral phosphoric acid is the basis for a highly efficient asymmetric dearomatization of naphthols. This protocol provides functionalized β-naphthalenone compounds with a chiral quaternary carbon center in excellent yields and enantioselectivity. These motifs are found in various biologically active natural products and therapeutic reagents.

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Photocatalysis

Metal-Free Carbonylations by Photoredox Catalysis

Ing. Michal Majek and Prof. Dr. Axel Jacobi von Wangelin

Metal-Free Carbonylations by Photoredox CatalysisA metal-free and base-free carbonylation has been developed which affords primary, secondary, and tertiary alkyl benzoates under irradiation with visible light in the presence of eosin Y as a photocatalyst. The mechanism has been studied by spectroscopic, theoretical, and preparative methods, and appears to involve intermediate aryl and aroyl radical species as well as a light-driven one-electron redox cycle without any sacrificial redox partner.

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Dynamic Heterogeneity

Ionic Liquids: Not only Structurally but also Dynamically Heterogeneous

Zhuan-Ping Zheng, Prof. Wen-Hui Fan, Soham Roy, Dr. Kamila Mazur, Andreas Nazet, Prof. Richard Buchner, Prof. Mischa Bonn and Dr. Johannes Hunger

Ionic Liquids: Not only Structurally but also Dynamically HeterogeneousSize doesn′t matter: The equilibration of the ionic ammonium group in protic ionic liquids after an ultrafast temperature jump depends on the anion but not on the size of the hydrophobic side chain. This equilibration of the ionic domains is approximately two times slower than restructuring within the hydrophobic alkyl domains, which demonstrates the dynamic heterogeneity in ionic liquids.

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Liquid Crystals

A Twist-Bend Nematic Phase Driven by Hydrogen Bonding

Suzanne M. Jansze, Dr. Alfonso Martínez-Felipe, Prof. John M. D. Storey, Dr. Antonius T. M. Marcelis and Prof. Corrie T. Imrie

A Twist-Bend Nematic Phase Driven by Hydrogen BondingIntriguing interplay: When the benzoic acid units in 4-[6-(4′-cyanobiphenyl-4-yl)hexyloxy]benzoic acid dimerize by hydrogen bonding (see picture), promesogenic liquid crystal trimers form. These supramolecular complexes show an enantiotropic nematic phase, which on cooling transforms into the twist-bend nematic phase in which the bent, achiral complexes spontaneously form helical structures.

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Gas Separation

Porous Liquids: A Promising Class of Media for Gas Separation

Dr. Jinshui Zhang, Dr. Song-Hai Chai, Dr. Zhen-An Qiao, Dr. Shannon M. Mahurin, Dr. Jihua Chen, Dr. Youxing Fang, Dr. Shun Wan, Kimberly Nelson, Dr. Pengfei Zhang and Prof. Sheng Dai

Porous Liquids: A Promising Class of Media for Gas SeparationPerforated liquids: Functionalizing hollow silica spheres with suitable polymer species can produce a porous liquid containing empty silica cavities. Taking advantage of their liquid-like polymeric matrixes as the separation medium and the empty cavities as the gas transport pathway they can function as a promising candidates for gas separation.

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Cobalt-Catalyzed C[BOND]H Cyanation of Arenes and Heteroarenes

M. Sc. Jie Li and Prof. Dr. Lutz Ackermann

Cobalt-Catalyzed C<img src="http://onlinelibrarystatic.wiley.com/undisplayable_characters/00f8ff.gif" alt="[BOND]" />H Cyanation of Arenes and HeteroarenesAs directed: The title reactions were accomplished with in situ generated cobalt(III) carboxylate complexes for highly efficient C[BOND]H activations. The direct cyanation proved viable with removable directing groups and displayed a broad substrate scope and mild reaction conditions.

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Amyloids

Atomic-Resolution Three-Dimensional Structure of Amyloid β Fibrils Bearing the Osaka Mutation

Dr. Anne K. Schütz, Dr. Toni Vagt, Dr. Matthias Huber, Dr. Oxana Y. Ovchinnikova, Riccardo Cadalbert, Dr. Joseph Wall, Prof. Dr. Peter Güntert, Dr. Anja Böckmann, Prof. Dr. Rudi Glockshuber and Prof. Dr. Beat H. Meier

Atomic-Resolution Three-Dimensional Structure of Amyloid β Fibrils Bearing the Osaka MutationA fold not observed before: The atomic-resolution fibril structure of the Aβ1-40 peptide with the Osaka mutation (E22Δ), which is associated with early-onset Alzheimer's disease, differs substantially from all previously proposed models. In this complex structure the deletion mutation is found in a β turn.

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Enzyme Inhibition

Benzoxazolone Carboxamides: Potent and Systemically Active Inhibitors of Intracellular Acid Ceramidase

Dr. Daniela Pizzirani, Dr. Anders Bach, Dr. Natalia Realini, Dr. Andrea Armirotti, Dr. Luisa Mengatto, Dr. Inga Bauer, Dr. Stefania Girotto, Dr. Chiara Pagliuca, Dr. Marco De Vivo, Dr. Maria Summa, Dr. Alison Ribeiro and Prof. Daniele Piomelli

Benzoxazolone Carboxamides: Potent and Systemically Active Inhibitors of Intracellular Acid CeramidaseA key regulator of the sphingolipid metabolism is acid ceramidase (AC), which offers a molecular target in disorders such as cancer and inflammation, in which sphingolipid signaling might be dysfunctional. The shown compound is metabolically stable, inhibits AC activity both in vitro and in vivo, and can thus be used as a potent chemical probe to investigate the roles of ceramides in physiology and pathology.

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Host–Guest Systems

Construction of Matryoshka-Type Structures from Supercharged Protein Nanocages

Dr. Tobias Beck, Stephan Tetter, Matthias Künzle and Prof. Dr. Donald Hilvert

Construction of Matryoshka-Type Structures from Supercharged Protein NanocagesCages within cages: By exploiting electrostatic interactions between two supercharged protein containers, namely supercharged lumazine synthase (red) and supercharged ferritin (blue) loaded with iron-oxide nanoparticles (black), nested Matryoshka-type structures were assembled. These cage-within-cage structures consist of two layers of protein surrounding iron oxide nanoparticles in a manner reminiscent of Russian dolls.

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Boron Redox Chemistry

Boron as a Powerful Reductant: Synthesis of a Stable Boron-Centered Radical-Anion Radical-Cation Pair

Dr. Philipp Bissinger, Prof. Dr. Holger Braunschweig, Dr. Alexander Damme, Dr. Christian Hörl, Dr. Ivo Krummenacher and Dr. Thomas Kupfer

Boron as a Powerful Reductant: Synthesis of a Stable Boron-Centered Radical-Anion Radical-Cation PairThe tailor-made diborene IiPr⋅(iPr)B[DOUBLE BOND]B(iPr)⋅IiPr features an extremely electron-rich B–B double bond making it one of the most powerful neutral organic reductants known to date (E1/2=−1.95 V). Its reducing power was successfully exploited in the synthesis of a very rare boron-centered radical-anion radical-cation pair by one-electron reduction of a borole, MesBC4Ph4. IiPr=1,3-diisopropylimidazol-2-ylidene.

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Sustainable Chemistry

Green-Solvent-Processed Molecular Solar Cells

Xiaofen Chen, Dr. Xiaofeng Liu, Mark A. Burgers, Dr. Ye Huang and Prof. Dr. Guillermo C. Bazan

Green-Solvent-Processed Molecular Solar CellsMolecular solar cells with high efficiencies can be fabricated from the green solvent 2-MeTHF. The light-harvesting semiconducting layer comprises a molecular donor with intermediate dimensions and a soluble fullerene derivative. No specific structural modifications are required on the semiconductors in order to use sustainable resources. PCE=power conversion efficiency.

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Carbon Materials

Graphitic Carbon Nitride Nanoribbons: Graphene-Assisted Formation and Synergic Function for Highly Efficient Hydrogen Evolution

Yang Zhao, Fei Zhao, Xiaopeng Wang, Chenyu Xu, Zhipan Zhang, Prof. Gaoquan Shi and Prof. Liangti Qu

Graphitic Carbon Nitride Nanoribbons: Graphene-Assisted Formation and Synergic Function for Highly Efficient Hydrogen EvolutionA non-metallic electrocatalyst: A three-dimensional architecture of in situ formed 1D graphitic carbon nitride nanoribbons on two-dimensional graphene sheets has been prepared (see picture). The compound is a highly efficient electrocatalyst for the hydrogen evolution and shows a low overpotential and an extremely large exchange current density, which is even larger than that of metal catalysts.

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Ligand-Controlled Regiodivergent Nickel-Catalyzed Annulation of Pyridones

Dr. Pavel A. Donets and Prof. Dr. Nicolai Cramer

Ligand-Controlled Regiodivergent Nickel-Catalyzed Annulation of PyridonesNickeled and dimed: Nickel(0)-catalyzed C[BOND]H functionalization of 2-pyridones and subsequent ligand-controlled regioselective cyclization affords 1,6-annulated 2-pyridones. Cyclooctadiene (L1) selectively leads to exo cyclization, whereas the addition of a bulky N-heterocyclic carbene ligand (L2) switches to the endo mode. The method was applied in the synthesis of the lupin alkaloid (±)-cytisine. LA=Lewis acid.

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Salt Nanocrystals

Electron-Driven Self-Assembly of Salt Nanocrystals in Liquid Helium

Dr. Matthias Daxner, Prof. Stephan Denifl, Prof. Paul Scheier and Prof. Andrew M. Ellis

Electron-Driven Self-Assembly of Salt Nanocrystals in Liquid HeliumSalting droplets: Electrons are used to initiate reaction between SF6 and sodium clusters inside helium nanodroplets. The resulting NaF products self-assemble into crystalline salt structures.

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Flow Chemistry

Rapid and Efficient Copper-Catalyzed Finkelstein Reaction of (Hetero)Aromatics under Continuous-Flow Conditions

Dr. Mao Chen, Saki Ichikawa and Prof. Dr. Stephen L. Buchwald

Rapid and Efficient Copper-Catalyzed Finkelstein Reaction of (Hetero)Aromatics under Continuous-Flow ConditionsSynthesis in flow: A flow system has been developed that enables a rapid halogen exchange in the copper-catalyzed Finkelstein reaction of (hetero)aromatics. A broad scope of iodo compounds was prepared in good to excellent yields. Furthermore, two multistep continuous-flow processes including either a halogen exchange/amidation or a halogen exchange/Mg–I exchange/nucleophilic addition sequence were established.

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Palladium Catalysis

Aerobic Palladium-Catalyzed Dioxygenation of Alkenes Enabled by Catalytic Nitrite

Zachary K. Wickens, Dr. Pablo E. Guzmán and Prof. Dr. Robert H. Grubbs

Aerobic Palladium-Catalyzed Dioxygenation of Alkenes Enabled by Catalytic NitriteCatalytic amounts of nitrite were found to enable the carbon–oxygen bond-forming reductive elimination from unstable alkyl palladium intermediates. Dioxygenated products could be obtained from alkenes in high yields, employing molecular oxygen as the terminal oxidant. Insight into the C–O bond forming reductive elimination was obtained using 18O-labeling experiments.

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Small-Molecule Trapping

Frustrated Lewis Pair Activation of an N-Sulfinylamine: A Source of Sulfur Monoxide

Lauren E. Longobardi, Vanessa Wolter and Prof. Dr. Douglas W. Stephan

Frustrated Lewis Pair Activation of an N-Sulfinylamine: A Source of Sulfur MonoxideSO good: Inter- and intramolecular P/B frustrated Lewis pairs are shown to react with an N-sulfinylamine to form PNSOB linkages. These species can be regarded as phosphinimine–borane-stabilized sulfur monoxide complexes, and they indeed act as sources of SO, effecting the oxidation of PPh3 and delivering SO to [RhCl(PPh3)3] and N-heterocyclic carbenes.

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Continuous Processing

A Systems Approach towards an Intelligent and Self-Controlling Platform for Integrated Continuous Reaction Sequences

Richard J. Ingham, Dr. Claudio Battilocchio, Daniel E. Fitzpatrick, Dr. Eric Sliwinski, Dr. Joel M. Hawkins and Prof. Steven V. Ley

A Systems Approach towards an Intelligent and Self-Controlling Platform for Integrated Continuous Reaction SequencesSmart control: A new conceptual framework for the integration of multiple flow chemistry operations and downstream processing methods is described. Real-time data sharing between devices enables the construction of complex bench-top machine-assisted synthesis platforms. The concept is applied to the synthesis of 2-aminoadamantane-2-carboxylic acid, incorporating three chemistry steps and three workup steps into a single system.

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Low-Coordinate Metal Centers

Two-Coordinate Iron(I) Complex [Fe{N(SiMe3)2}2]: Synthesis, Properties, and Redox Activity

Dr. C. Gunnar Werncke, Philip C. Bunting, Dr. Carine Duhayon, Prof. Jeffrey R. Long, Dr. Sébastien Bontemps and Dr. Sylviane Sabo-Etienne

Two-Coordinate Iron(I) Complex [Fe{N(SiMe3)2}2]−: Synthesis, Properties, and Redox ActivityI, II, III, Iron: The linear two-coordinate iron(I) complex [Fe{N(SiMe3)2}2] is isolated in high yield through the reduction of either [Fe{N(SiMe3)2}2] or [Fe{N(SiMe3)2}2(PCy3)]. One- and two-electron oxidation by reaction with I2 affords the corresponding iodo iron(II) and diiodo iron(III) complexes.

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Sonocrystallization

Sonocrystallization Yields Monoclinic Paracetamol with Significantly Improved Compaction Behavior

Dr. Dejan-Krešimir Bučar, Dr. James A. Elliott, Dr. Mark D. Eddleston, Dr. Jeremy K. Cockcroft and Prof. William Jones

Sonocrystallization Yields Monoclinic Paracetamol with Significantly Improved Compaction BehaviorCompact discs: Experimental compaction and finite element analysis have shown that the poor compaction properties of paracetamol can be improved through sonocrystallization. The superior tabletability is attributed to the enhanced capacity of the solid to plastically deform and the increased cohesive interactions between its particles.

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Catalyst Design

Molybdenum Phosphosulfide: An Active, Acid-Stable, Earth-Abundant Catalyst for the Hydrogen Evolution Reaction

Dr. Jakob Kibsgaard and Prof. Thomas F. Jaramillo

Molybdenum Phosphosulfide: An Active, Acid-Stable, Earth-Abundant Catalyst for the Hydrogen Evolution ReactionIntroducing sulfur into the surface of molybdenum phosphide produces a molybdenum phosphosulfide catalyst with outstanding activity and stability for the hydrogen evolution reaction (HER) in acidic environments. Synergistic effects between sulfur and phosphorus produce an electrode that is more active than those based on either the pure sulfide or the pure phosphide.

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Energy Storage Devices

Flexible and Stretchable Lithium-Ion Batteries and Supercapacitors Based on Electrically Conducting Carbon Nanotube Fiber Springs

Ye Zhang, Wenyu Bai, Dr. Xunliang Cheng, Jing Ren, Dr. Wei Weng, Peining Chen, Xin Fang, Zhitao Zhang and Prof. Huisheng Peng

Flexible and Stretchable Lithium-Ion Batteries and Supercapacitors Based on Electrically Conducting Carbon Nanotube Fiber SpringsMy flexible friend: Springlike electrodes with remarkable electrochemical properties have been used to create flexible and stretchable fiber-shaped supercapacitors and lithium-ion batteries. The electrodes, which are made from twisted aligned multiwalled carbon nanotubes (see picture), can be stretched by over 300 %, and the devices show stable performance under bending and stretching deformations.

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Click Chemistry

“Photoclick” Postsynthetic Modification of DNA

Dipl.-Chem. Stefanie Arndt and Prof. Dr. Hans-Achim Wagenknecht

“Photoclick” Postsynthetic Modification of DNAA light click away: The diaryltetrazole group at the 5-position of 2′-deoxyuridine allows the photoinduced postsynthetic modification with maleimide-functionalized sulfo-Cy3 dye.

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Asymmetric Synthesis

Copper-Catalyzed Asymmetric Synthesis of Tertiary α-Hydroxy Phosphonic Acid Derivatives with In Situ Generated Nitrosocarbonyl Compounds as the Oxygen Source

Dr. Biplab Maji and Prof. Dr. Hisashi Yamamoto

Copper-Catalyzed Asymmetric Synthesis of Tertiary α-Hydroxy Phosphonic Acid Derivatives with In Situ Generated Nitrosocarbonyl Compounds as the Oxygen SourceGo for oxygen: The copper-catalyzed direct α-oxidation of racemic β-ketophosphonates using nitrosocarbonyl compounds as an electrophilic oxygen source is a new method for the asymmetric synthesis of biogenic tertiary α-hydroxy phosphonic acid derivatives. Highly efficient asymmetric hydroxylations could thus be achieved at room temperature under mild conditions.

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Nonlinear Optical Materials

Synthesis, Structure, and Frequency-Doubling Effect of Calcium Cyanurate

Dr. Markus Kalmutzki, Dr. Markus Ströbele, Dipl.-Chem. Frank Wackenhut, Prof. Dr. Alfred J. Meixner and Prof. Dr. H.-Jürgen Meyer

Synthesis, Structure, and Frequency-Doubling Effect of Calcium CyanurateThe alkaline-earth cyanurate Ca3(O3C3N3)2 (CCY) was produced in a solid-state metathesis reaction through the cyclotrimerization of cyanate ions. The crystal structure of CCY is closely related to the structure of β-BBO. Crystalline CCY promises to be amongst the most efficient frequency doubling materials.

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Hydroboration

Hydroboration of Arynes with N-Heterocyclic Carbene Boranes

Dr. Tsuyoshi Taniguchi and Prof. Dr. Dennis P. Curran

Hydroboration of Arynes with N-Heterocyclic Carbene BoranesA new partnership with a future: N-Heterocyclic carbene (NHC) boranes coupled with arynes in a hydroboration reaction to produce various B-aryl-substituted NHC-boranes (see scheme), which are stable and have many potential uses. The proposed hydride-transfer character of the mechanism was supported by the ortho regioselectivity observed for the hydroboration of arynes with an electron-withdrawing substituent.

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Phospholipid Membranes

In Situ Vesicle Formation by Native Chemical Ligation

Dr. Roberto J. Brea, Christian M. Cole and Prof. Neal K. Devaraj

In Situ Vesicle Formation by Native Chemical LigationSpontaneous growth: Native chemical ligation (NCL) can be used to prepare phospholipids spontaneously at neutral pH from thioesters. The lipids self-assemble in situ to form vesicles up to several micrometers in diameter. Thanks to the chemoselectivity of NCL, this method of membrane formation in situ is compatible with biological materials.

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Antimicrobial Peptides

Combining Topology and Sequence Design for the Discovery of Potent Antimicrobial Peptide Dendrimers against Multidrug-Resistant Pseudomonas aeruginosa

Michaela Stach, Thissa N. Siriwardena, Dr. Thilo Köhler, Prof. Dr. Christian van Delden, Priv.-Doz. Dr. Tamis Darbre and Prof. Dr. Jean-Louis Reymond

Combining Topology and Sequence Design for the Discovery of Potent Antimicrobial Peptide Dendrimers against Multidrug-Resistant Pseudomonas aeruginosaMultidrug-resistant bacteria, such as Pseudomonas aeruginosa and Acinetobacter baumannii, are a major public health threat. By combining topology and amino acid sequence design, new antimicrobial peptide dendrimers with high activity against these pathogens were found, which represents a new and general approach for the discovery of antimicrobial agents.

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Practical and Highly Selective C[BOND]H Functionalization of Structurally Diverse Ethers

Miao Wan, Zhilin Meng, Prof. Hongxiang Lou and Prof. Lei Liu

Practical and Highly Selective C<img src="http://onlinelibrarystatic.wiley.com/undisplayable_characters/00f8ff.gif" alt="[BOND]" />H Functionalization of Structurally Diverse EthersA practical trityl ion mediated C[BOND]H functionalization of ethers has been disclosed. The reaction proceeds at ambient temperature with high chemoselectivity and good functional-group tolerance. The protocol displays excellent regio- and diastereoselectivities for unsymmetric ethers, thus stereoselectively yielding highly functionalized trans-disubstituted tetrahydrofuran, tetrahydropyran, dihydropyran, and isochroman moieties.

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Protein Folding

Capturing the Mechanical Unfolding Pathway of a Large Protein with Coiled-Coil Probes

Qing Li, Zackary N. Scholl and Prof. Piotr E. Marszalek

Capturing the Mechanical Unfolding Pathway of a Large Protein with Coiled-Coil ProbesAn antiparallel coiled coil (CC) mechanical probe that can be used to assess the unfolding mechanism of a protein is developed. When a protein is studied by single-molecule force spectroscopy, the probe enables the assignment of force peaks to structural elements when the unfolding process passes through the location of the CC probe without significant disturbance of the host protein structure.

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Anti-Corrosion Coatings

Polyoxometalate Ionic Liquids as Self-Repairing Acid-Resistant Corrosion Protection

M. Sc. Sven Herrmann, M. Sc. Monika Kostrzewa, Prof. Dr. Andreas Wierschem and Prof. Dr. Carsten Streb

Polyoxometalate Ionic Liquids as Self-Repairing Acid-Resistant Corrosion ProtectionThis corrosion: Hydrophobic polyoxometalate-based ionic liquids (POM-ILs) are used as temporary acid-resistant coatings for copper metal. Complete protection against acid vapors and liquid acids is observed and the POM-IL coating can withstand mechanical damage by a self-repairing mechanism. The compounds are easily removed and recovered for subsequent usage.

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Lithium Batteries

Excellent Stability of a Lithium-Ion-Conducting Solid Electrolyte upon Reversible Li+/H+ Exchange in Aqueous Solutions

Dr. Cheng Ma, Dr. Ezhiylmurugan Rangasamy, Dr. Chengdu Liang, Prof. Jeffrey Sakamoto, Dr. Karren L. More and Dr. Miaofang Chi

Excellent Stability of a Lithium-Ion-Conducting Solid Electrolyte upon Reversible Li+/H+ Exchange in Aqueous SolutionsIn sharp contrast to other garnets, the cubic Li7La3Zr2O12 preserved its structure upon Li+/H+ exchange in aqueous solutions. Subsequent immersion in a 2 M LiOH solution gave reverse Li+/H+ exchange, and the structure remained unchanged. Thus cubic Li7La3Zr2O12 has the desired properties to be the solid electrolyte in aqueous lithium batteries.

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Enzymatic Route to Cyclic Peptides

An Efficient Method for the In Vitro Production of Azol(in)e-Based Cyclic Peptides

Dr. Wael E. Houssen, Andrew F. Bent, Dr. Andrew R. McEwan, Nathalie Pieiller, Dr. Jioji Tabudravu, Dr. Jesko Koehnke, Greg Mann, Rosemary I. Adaba, Dr. Louise Thomas, Dr. Usama W. Hawas, Dr. Huanting Liu, Dr. Ulrich Schwarz-Linek, Prof. Margaret C. M. Smith, Prof. James H. Naismith and Prof. Marcel Jaspars

An Efficient Method for the In Vitro Production of Azol(in)e-Based Cyclic PeptidesHeterocycle-containing cyclic peptides are promising scaffolds for the pharmaceutical industry, but their chemical synthesis is very challenging. A new universal method has been devised to prepare these compounds using a set of engineered marine-derived enzymes and substrates.

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Natural Product Synthesis

Total Synthesis of the Tetracyclic Antimalarial Alkaloid (±)-Myrioneurinol

Anthony J. Nocket and Prof. Dr. Steven M. Weinreb

Total Synthesis of the Tetracyclic Antimalarial Alkaloid (±)-MyrioneurinolMalaria’s worst nightmare: A total synthesis of the tetracyclic antimalarial Myrioneuron alkaloid (±)-myrioneurinol features three highly diastereoselective reactions as the key steps: an intramolecular Michael addition of a lactam titanium enolate to an α,β-unsaturated ester, a conjugate addition of a malonate enolate to a nitrosoalkene, and an intramolecular aza-Sakurai reaction.

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Total Synthesis

A Cascade Strategy Enables a Total Synthesis of (−)-Gephyrotoxin

Shuyu Chu, Dr. Stephen Wallace and Prof. Dr. Martin D. Smith

A Cascade Strategy Enables a Total Synthesis of (−)-GephyrotoxinThe concise synthesis of (−)-gephyrotoxin from L-pyroglutaminol involves a diastereoselective intramolecular enamine/Michael cascade reaction that forms two rings and two stereocenters and generates a stable tricyclic iminium cation. A hydroxy-directed reduction of this intermediate plays a key role in establishing the required cis-configured decahydroquinoline ring system.

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Oxygen Storage

Metal–Organic Frameworks for Oxygen Storage

Dr. Jared B. DeCoste, Dr. Mitchell H. Weston, Patrick E. Fuller, Trenton M. Tovar, Gregory W. Peterson, Dr. M. Douglas LeVan and Dr. Omar K. Farha

Metal–Organic Frameworks for Oxygen StorageMOFs store oxygen too: Two metal–organic frameworks with open metal sites store oxygen at capacities far greater than that of an empty cylinder and are comparable to the state-of-the-art oxygen storage materials. Self-assembled materials allow for rational design of materials for adsorption of specific gases.

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Carbon Clusters

The Structure and Stability of Magic Carbon Clusters Observed in Graphene Chemical Vapor Deposition Growth on Ru(0001) and Rh(111) Surfaces

Dr. Junfeng Gao and Prof. Feng Ding

The Structure and Stability of Magic Carbon Clusters Observed in Graphene Chemical Vapor Deposition Growth on Ru(0001) and Rh(111) SurfacesNucleation of graphene: A new carbon cluster, composed of a C21 core and three dangling carbon atoms, is found to be exceptionally stable (see picture). This cluster is the most probable carbon cluster observed during the growth of graphene on Ru(0001) and Rh(111) surfaces by chemical vapor deposition.

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Hydrogen Production

A Molecular Copper Catalyst for Electrochemical Water Reduction with a Large Hydrogen-Generation Rate Constant in Aqueous Solution

Peili Zhang, Prof. Mei Wang, Yong Yang, Tianyi Yao and Prof. Licheng Sun

A Molecular Copper Catalyst for Electrochemical Water Reduction with a Large Hydrogen-Generation Rate Constant in Aqueous SolutionAcidic electrolysis: An ionic copper amine-pyridine complex displayed a hydrogen-generation rate constant (kobs) of over 10000 s−1 in pH 2.5 buffer solutions. A turnover frequency of 7000 h−1 cm−2 and a Faradaic efficiency of 96 % were measured in an extended controlled potential electrolysis experiment at −0.90 V versus the standard hydrogen electrode over two hours using a glassy carbon electrode.

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Bacteria Identification

Identification of Bacteria in Water by a Fluorescent Array

Wenwen Chen, Prof. Qizhai Li, Wenshu Zheng, Fang Hu, Prof. Guanxin Zhang, Prof. Zhuo Wang, Prof. Deqing Zhang and Prof. Xingyu Jiang

Identification of Bacteria in Water by a Fluorescent ArrayWhat's this bug? Probes with special fluorescent characteristics are used to fabricate an array (F-array) for bacteria identification with the assistance of statistical methods. Eight kinds of bacteria are discriminated successfully; even normal bacteria and multidrug-resistant bacteria can be distinguished. The method is easy to perform, fast, and effective.

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Enzymatic Mechanisms

Direct Evidence for a Peroxide Intermediate and a Reactive Enzyme–Substrate–Dioxygen Configuration in a Cofactor-free Oxidase

Dr. Soi Bui, Dr. David von Stetten, Dr. Pablo G. Jambrina, Prof. Thierry Prangé, Dr. Nathalie Colloc'h, Dr. Daniele de Sanctis, Dr. Antoine Royant, Dr. Edina Rosta and Dr. Roberto A. Steiner

Direct Evidence for a Peroxide Intermediate and a Reactive Enzyme–Substrate–Dioxygen Configuration in a Cofactor-free OxidasePeroxide intermediate: X-ray crystallography supported by in crystallo Raman spectroscopy and QM/MM methods reveals that the archetypical cofactor-free uricase catalyzes urate degradation via a C5(S)-peroxide intermediate. X-rays break the peroxide C5[BOND]OO(H) carbon–oxygen bond releasing dioxygen in situ, affording exquisite insight into the reactants′ configuration leading to the peroxo intermediate.

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Asymmetric Synthesis

Organocatalytic and Scalable Synthesis of the Anti-Influenza Drugs Zanamivir, Laninamivir, and CS-8958

Dr. Junshan Tian, Jiankang Zhong, Yunsheng Li and Prof. Dr. Dawei Ma

Organocatalytic and Scalable Synthesis of the Anti-Influenza Drugs Zanamivir, Laninamivir, and CS-8958A strategy to combat the flu: The anti-influenza drugs zanamivir and laninamivir (see structures) were synthesized in only 13 steps from inexpensive D-araboascorbic acid by the use of an organocatalytic Michael addition and a metal-catalyzed anti-selective Henry reaction as key transformations. This cost-effective, straightforward, and efficient approach enabled the synthesis of more than 3.5 g of zanamivir.

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Rhodium Catalysis

A Complete Switch of the Directional Selectivity in the Annulation of 2-Hydroxybenzaldehydes with Alkynes

Dr. Huiying Zeng and Prof. Dr. Chao-Jun Li

A Complete Switch of the Directional Selectivity in the Annulation of 2-Hydroxybenzaldehydes with AlkynesRodeo rhodium: Different natural product skeletons can be obtained from the same simple starting materials by using different catalytic systems. The gold-catalyzed annulation of terminal alkynes and salicylaldehydes yielded isoflavanones, whereas the rhodium-catalyzed version led to coumarin skeletons.

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Biosensors

Photocaged DNAzymes as a General Method for Sensing Metal Ions in Living Cells

Kevin Hwang, Peiwen Wu, Taejin Kim, Lei Lei, Shiliang Tian, Prof. Yingxiao Wang and Prof. Yi Lu

Photocaged DNAzymes as a General Method for Sensing Metal Ions in Living CellsThe attachment of a photolabile protecting group (PG) to a DNAzyme allows its delivery into cells, where irradiation with light restores its activity, thus allowing temporal control over the sensing of metal ions. F=fluorophore, Q=quencher.

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