Angewandte Chemie International Edition

Cover image for Vol. 53 Issue 43

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.

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.

Read more now


 

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.

Read more now


 

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.

Read more now


 

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.

Read more now


 

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.

Read more now


 

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.

Read more now


 

Natural Product Synthesis

Stereodivergent Total Synthesis of Δ9-Tetrahydrocannabinols

Michael A. Schafroth, Giuseppe Zuccarello, Simon Krautwald, Dr. David Sarlah and Prof. Dr. Erick M. Carreira

Stereodivergent Total Synthesis of Δ9-TetrahydrocannabinolsNo stereoisomer left behind: A concise synthesis of tetrahydrocannabinol (THC) is described that provides rapid and controlled access to any stereoisomer of the product, including the naturally occurring stereoisomers Δ9-trans-THC and Δ9-cis-THC. By application of stereodivergent dual catalysis to the same set of starting materials, all four isomers of THC were obtained in five steps using a uniform synthetic sequence and identical reaction conditions.

Read more now


 

Surface Analysis

Using Surface Segregation To Design Stable Ru-Ir Oxides for the Oxygen Evolution Reaction in Acidic Environments

Dr. Nemanja Danilovic, Dr. Ramachandran Subbaraman, Dr. Kee Chul Chang, Dr. Seo Hyoung Chang, Dr. Yijin Kang, Dr. Joshua Snyder, Dr. Arvydas Paul Paulikas, Dr. Dusan Strmcnik, Prof. Yong Tae Kim, Dr. Deborah Myers, Dr. Vojislav R. Stamenkovic and Dr. Nenad M. Markovic

Using Surface Segregation To Design Stable Ru-Ir Oxides for the Oxygen Evolution Reaction in Acidic EnvironmentsA hive of activity: Tuning the near-surface composition of Ru and Ir elements in a bimetallic oxide by surface segregation results in the formation of a nanosegregated domain (see picture) that balances the stability and activity of surface atoms. A Ru0.5Ir0.5 alloy prepared by this method exhibited a stability four-times higher than the best Ru-Ir oxygen evolution reaction materials, but the same activity.

Read more now


 

DNA nanotechnology

Membrane-Spanning DNA Nanopores with Cytotoxic Effect

Dr. Jonathan R. Burns, Noura Al-Juffali, Dr. Sam M. Janes and Dr. Stefan Howorka

Membrane-Spanning DNA Nanopores with Cytotoxic EffectDNA-based cytotoxic agents: Nanopores composed of folded DNA featuring a hydrophobic belt of ethyl phosphorothioate groups insert into bilayer membranes and kill cancer cells (see picture). The mode by which the pores achieve cell killing is elucidated with confocal microscopy.

Read more now


 

Macrolide Total Synthesis

Chemoenzymatic Synthesis of Spinosyn A

Prof. Dr. Hak Joong Kim, Dr. Sei-hyun Choi, Byung-sun Jeon, Dr. Namho Kim, Prof. Dr. Rongson Pongdee, Dr. Qingquan Wu and Prof. Dr. Hung-wen Liu

Chemoenzymatic Synthesis of Spinosyn AFirst chemistry, then biology: For the total synthesis of spinosyn A, the monocyclic macrolide precursor was constructed by conventional chemical methods. The synthetically challenging structural elements were introduced by the use of eight enzymes in a “one-pot” reaction system. Final chemical forosamylation of 17-pseudoglycone completed the total synthesis.

Read more now


 

Vesicle Formation

Thermally Triggered Frame-Guided Assembly

Dr. Zhiyong Zhao, Chun Chen, Yuanchen Dong, Prof. Dr. Zhongqiang Yang, Prof. Dr. Qing-Hua Fan and Prof. Dr. Dongsheng Liu

Thermally Triggered Frame-Guided AssemblyYou've been framed: By employing the thermally responsive poly(propylene oxide) (PPO) as the leading hydrophobic groups (LHGs) on gold nanoparticles, a frame-guided assembly strategy could be triggered by temperature change. Increasing the temperature above the low critical solution temperature (LCST), the PPO became hydrophobic allowing DNA-b-PPO to assemble around the nanoparticle frame by hydrophobic interactions generating vesicles.

Read more now


 

Germanosilicates

Zeolites with Continuously Tuneable Porosity

Dr. Paul S. Wheatley, Dr. Pavla Chlubná-Eliášová, Dr. Heather Greer, Prof. Wuzong Zhou, Dr. Valerie R. Seymour, Dr. Daniel M. Dawson, Prof. Sharon E. Ashbrook, Dr. Ana B. Pinar, Dr. Lynne B. McCusker, Dr. Maksym Opanasenko, Prof. Jiří Čejka and Prof. Russell E. Morris

Zeolites with Continuously Tuneable PorosityADORable zeolites: A series of zeolites with continuously tuneable porosity was prepared using the assembly–disassembly–organization–reassembly (ADOR) method. The pores of the zeolites that are accessible with this method cover the whole range of useable sizes: from small to extra-large.

Read more now


 

Mass Spectrometry

Direct Mass Spectrometry Analysis of Biofluid Samples Using Slug-Flow Microextraction Nano-Electrospray Ionization

Yue Ren, Morgan N. McLuckey, Jiangjiang Liu and Prof. Zheng Ouyang

Direct Mass Spectrometry Analysis of Biofluid Samples Using Slug-Flow Microextraction Nano-Electrospray IonizationGo with the flow: High sensitivity and quantitation precision have been achieved by using a single-step method based on slug-flow microextraction and nano-electrospray ionization (Nano-ESI) for the MS analysis of organic compounds in only 5 μL of a biofluid. Real-time chemical derivatization allows the analysis of anabolic steroids, and monitoring the enzymatic functions of wet blood is also possible.

Read more now


 

Lithium–Oxygen Batteries

Liquid-Free Lithium–Oxygen Batteries

Moran Balaish, Prof. Emanuel Peled, Prof. Diana Golodnitsky and Prof. Yair Ein-Eli

Liquid-Free Lithium–Oxygen BatteriesA polymer-based system: Rechargeable lithium–oxygen cells based on a solid polymer electrolyte (SPE) were operated at a temperature higher than the melting point of the polymer electrolyte. The proposed SPE-based Li-O2 cells showed a stable cycling, possessing a higher cell discharge voltage and a drastically lower charge voltage.

Read more now


 

Photoelectrochemistry

Forming Buried Junctions to Enhance the Photovoltage Generated by Cuprous Oxide in Aqueous Solutions

Pengcheng Dai, Wei Li, Jin Xie, Yumin He, James Thorne, Dr. Gregory McMahon, Prof. Dr. Jinhua Zhan and Prof. Dr. Dunwei Wang

Forming Buried Junctions to Enhance the Photovoltage Generated by Cuprous Oxide in Aqueous SolutionsThe photovoltage generated by Cu2O in H2O is readily increased by decorating the surface with a thin ZnS layer, which replaces the Cu2O/H2O interface and improves charge separation by Cu2O. The strategy is compatible with stabilizing Cu2O with TiO2 and with various catalysts that promote the hydrogen evolution reaction and may enable the development of dual-absorber water splitting systems with the photocathode as the top layer.

Read more now


 

Combined Catalysis

Synthesis of Indoles Using Visible Light: Photoredox Catalysis for Palladium-Catalyzed C[BOND]H Activation

Dipl.-Chem. Jochen Zoller, M. Sc. David C. Fabry, B. Sc. Meria A. Ronge and Prof. Dr. Magnus Rueping

Synthesis of Indoles Using Visible Light: Photoredox Catalysis for Palladium-Catalyzed C<img src="http://onlinelibrarystatic.wiley.com/undisplayable_characters/00f8ff.gif" alt="[BOND]" />H ActivationCoupling without coinage metals: A combined palladium- and photoredox-catalyzed C[BOND]H olefination serves to synthesize indoles. Using visible light, direct C[BOND]H activation of aromatic enamines leads to a variety of indole derivatives in good yields under mild reaction conditions.

Read more now


 

Ion-Selective Channels

Supramolecular Gating of Ion Transport in Nanochannels

B. V. V. S. Pavan Kumar, Dr. K. Venkata Rao, Prof. S. Sampath, Dr. Subi J. George and Muthusamy Eswaramoorthy

Supramolecular Gating of Ion Transport in NanochannelsThe charge-transfer interactions between dicationic viologen (acceptor) and trianionic pyranine (donor) were exploited to realize charge-reversal in nanochannels. Ion transport was switched from anion selective to ambipolar to cation selective by controlling the extent of viologen bound to the pyranine. Ion transport regulation with respect to pH was achieved by selecting a donor with pH-responsive functional groups.

Read more now


 

NMR Spectroscopy

HyperBIRD: A Sensitivity-Enhanced Approach to Collecting Homonuclear-Decoupled Proton NMR Spectra

Dr. Kevin J. Donovan and Prof. Lucio Frydman

HyperBIRD: A Sensitivity-Enhanced Approach to Collecting Homonuclear-Decoupled Proton NMR SpectraHyperBIRD: An approach to acquire 1H NMR spectra with enhanced sensitivity and resolution is presented. It is based on polarizing ex situ the 13C nuclei, let this polarization spontaneously enhance the C-bonded 1H nuclei, and detect solely the latter using a single-scan BIRD sequence that delivers homo- and heter-decoupled 1H spectra.

Read more now


 

Methylation

Metal-Free Catalyst for the Chemoselective Methylation of Amines Using Carbon Dioxide as a Carbon Source

Dr. Shoubhik Das, Felix D. Bobbink, Prof. Dr. Gabor Laurenczy and Prof. Dr. Paul J. Dyson

Metal-Free Catalyst for the Chemoselective Methylation of Amines Using Carbon Dioxide as a Carbon SourceThe methylation of amines with CO2 as C1 source and Ph2SiH2 as reducing agent was achieved with an N-heterocyclic carbene (NHC) as the catalyst. The catalyst is tolerant toward a variety of functional groups (including esters and ethers, nitro, nitrile, and carbonyl groups, and unsaturated C[BOND]C bonds), uses commercially available reagents, and can be performed on a gram scale.

Read more now


 

Heterogeneous Catalysis

Geometry-Assisted Three-Dimensional Superlocalization Imaging of Single-Molecule Catalysis on Modular Multilayer Nanocatalysts

Dr. Rui Han, Dr. Ji Won Ha, Dr. Chaoxian Xiao, Yuchen Pei, Zhiyuan Qi, Bin Dong, Nicholas L. Bormann, Prof. Dr. Wenyu Huang and Prof. Dr. Ning Fang

Geometry-Assisted Three-Dimensional Superlocalization Imaging of Single-Molecule Catalysis on Modular Multilayer NanocatalystsA multilayer catalyst that consists of a solid silica core, a mesoporous silica shell, and uniformly distributed Pt nanoparticles sandwiched between these layers was synthesized. 3D high-resolution super-localization was then used to image single fluorescent molecules produced at active sites on the core–shell model nanocatalysts.

Read more now


 

Cancer Sensitization

A Small Molecule Inhibits Protein Disulfide Isomerase and Triggers the Chemosensitization of Cancer Cells

Dr. Jürgen Eirich, Dr. Simone Braig, Dr. Liliana Schyschka, Phil Servatius, Judith Hoffmann, Sabrina Hecht, Prof. Dr. Simone Fulda, Prof. Dr. Stefan Zahler, Prof. Dr. Iris Antes, Prof. Dr. Uli Kazmaier, Prof. Dr. Stephan A. Sieber and Prof. Dr. Angelika M. Vollmar

A Small Molecule Inhibits Protein Disulfide Isomerase and Triggers the Chemosensitization of Cancer CellsIn the battle against the chemoresistance of cancer cells a screening approach has identified a novel compound class that sensitizes cancer cells in combination with etoposide. Proteomic target discovery revealed the reversible inhibition of protein disulfide isomerase as the molecular mechanism, which was further supported by cellular imaging studies and docking and biochemical assays in various cancer model systems.

Read more now


 

Asymmetric Catalysis

Catalytic Enantioselective Synthesis of Atropisomeric Biaryls: A Cation-Directed Nucleophilic Aromatic Substitution Reaction

Roly J. Armstrong and Prof. Dr. Martin D. Smith

Catalytic Enantioselective Synthesis of Atropisomeric Biaryls: A Cation-Directed Nucleophilic Aromatic Substitution ReactionAsymm-Desymm: A catalytic asymmetric nucleophilic aromatic substitution reaction which yields axially chiral biaryls in excellent yields with e.r. values of up to 97:3 has been developed. This process uses a chiral counterion to direct the addition of thiophenolate to an achiral dichloropyrimidine by a tandem desymmetrization/kinetic resolution mechanism. The products can be derivatized, thus offering access to unexplored chiral biaryl architectures.

Read more now


 

Single-Molecule Magnets

A Heterometallic FeII–DyIII Single-Molecule Magnet with a Record Anisotropy Barrier

Jun-Liang Liu, Jie-Yi Wu, Yan-Cong Chen, Dr. Valeriu Mereacre, Prof. Dr. Annie K. Powell, Dr. Liviu Ungur, Prof. Dr. Liviu F. Chibotaru, Prof. Dr. Xiao-Ming Chen and Prof. Dr. Ming-Liang Tong

A Heterometallic FeII–DyIII Single-Molecule Magnet with a Record Anisotropy BarrierA record anisotropy barrier of 319 cm−1 was observed for a FeII-DyIII-FeII single-molecule magnet, which possesses two asymmetric and distorted FeII ions and one quasi-D5h DyIII ion. The frozen magnetization of the DyIII ions leads to the slowed relaxation of the FeII ions in the Mössbauer spectrum. Ab initio calculations suggest that tunneling is interrupted effectively thanks to the exchange doublets.

Read more now


 

Photochemistry

[2+2] Photocycloaddition of 3-Alkenyloxy-2-cycloalkenones: Enantioselective Lewis Acid Catalysis and Ring Expansion

M. Sc. Richard Brimioulle and Prof. Dr. Thorsten Bach

[2+2] Photocycloaddition of 3-Alkenyloxy-2-cycloalkenones: Enantioselective Lewis Acid Catalysis and Ring ExpansionRing-a-ring o'roses: An enantioselective, Lewis acid catalyzed [2+2] photocycloaddition (9 examples, 69–94 % yield, up to 94 % ee) leads to tricyclic products, in which the marked bond of the cyclobutane ring can be cleaved to form medium-sized rings as shown in the example above.

Read more now


 

Sodium-Ion Batteries

MoS2 Nanoflowers with Expanded Interlayers as High-Performance Anode for Sodium-Ion Batteries

Zhe Hu, Lixiu Wang, Dr. Kai Zhang, Dr. Jianbin Wang, Prof. Fangyi Cheng, Prof. Zhanliang Tao and Prof. Jun Chen

MoS2 Nanoflowers with Expanded Interlayers as High-Performance Anode for Sodium-Ion BatteriesMore active sites through peeling: MoS2 nanoflowers with expanded interlayers were investigated as high-performance anode material for Na-ion batteries. Excellent discharge capacities and high cycling stability were observed and were directly correlated with the expanded layer space and the decreased layer numbers.

Read more now


 

Photochemistry

Enantioselective Synthesis of a Chiral Coordination Polymer with Circularly Polarized Visible Laser

Dr. Shu-Ting Wu, Zhen-Wen Cai, Qiao-Yan Ye, Chen-Hao Weng, Dr. Xi-He Huang, Dr. Xiao-Lin Hu, Dr. Chang-Cang Huang and Dr. Nai-Feng Zhuang

Enantioselective Synthesis of a Chiral Coordination Polymer with Circularly Polarized Visible LaserWith a twist of light: The enantioselective synthesis of the [{P/M-Cu(succinate)(4,4′-bipyridine)}n]⋅(4 H2O)n coordination polymer was achieved by using a circularly polarized visible laser, and thus provides a strategy for the control of the chirality of chiral coordination polymers. CPL=circularly polarized light.

Read more now


 

Biosensors

A Method for Evaluating the Level of Soluble β-Amyloid(1–40/1–42) in Alzheimer’s Disease Based on the Binding of Gelsolin to β-Amyloid Peptides

Dr. Yanyan Yu, Lin Zhang, Dr. Chenglin Li, Xiaoyu Sun, Dr. Daoquan Tang and Prof. Guoyue Shi

A Method for Evaluating the Level of Soluble β-Amyloid(1–40/1–42) in Alzheimer’s Disease Based on the Binding of Gelsolin to β-Amyloid PeptidesAmyloid assay: A selective gelsolin-based electrochemical probe was designed that can specifically bind the β-amyloid peptides Aβ(1–40/1–42) (yellow and green) to quantify variations in Aβ levels in Alzheimer’s disease (AD). This sensitive method makes use of the amplifying features of AuNPs and was successfully used to evaluate variations in the Aβ content of the cerebrospinal fluid and brain tissues of normal and AD-affected rats.

Read more now


 

Ester Ligation

Formation and Rearrangement of Homoserine Depsipeptides and Depsiproteins in the α-Ketoacid–Hydroxylamine Ligation with 5-Oxaproline

Thomas G. Wucherpfennig, Florian Rohrbacher, Dr. Vijaya R. Pattabiraman and Prof. Dr. Jeffrey W. Bode

Formation and Rearrangement of Homoserine Depsipeptides and Depsiproteins in the α-Ketoacid–Hydroxylamine Ligation with 5-OxaprolineThe primary products of the chemical ligations of α-ketoacids and 5-oxaproline peptides are esters, rather than the previously reported amides (see scheme). The depsipeptide products rapidly rearrange to the amides in basic buffers. The formation of esters sheds light on possible mechanisms for the type II KAHA ligations and opens a new avenue for the chemical synthesis of depsiproteins.

Read more now


 

Antimicrobial Peptides

Insect-Derived Proline-Rich Antimicrobial Peptides Kill Bacteria by Inhibiting Bacterial Protein Translation at the 70 S Ribosome

Andor Krizsan, Dr. Daniela Volke, Stefanie Weinert, Prof.Dr. Norbert Sträter, Dr. Daniel Knappe and Prof.Dr. Ralf Hoffmann

Insect-Derived Proline-Rich Antimicrobial Peptides Kill Bacteria by Inhibiting Bacterial Protein Translation at the 70 S RibosomeLost in translation: Proline-rich antimicrobial peptides (PrAMPs) inhibit bacterial protein translation by binding to the 70S ribosome of Gram-negative bacteria. This represents a novel killing mechanism for gene-encoded antimicrobial peptides. Alanine substitutions in the peptides additionally identified specific basic and hydrophobic residues as major interaction sites, which will enable the design of optimized compounds.

Read more now


 

Natural Product Synthesis

Enantioselective Divergent Syntheses of Several Polyhalogenated Plocamium Monoterpenes and Evaluation of Their Selectivity for Solid Tumors

Carl V. Vogel, Halina Pietraszkiewicz, Omar M. Sabry, Prof. William H. Gerwick, Dr. Frederick A. Valeriote and Prof. Christopher D. Vanderwal

Enantioselective Divergent Syntheses of Several Polyhalogenated Plocamium Monoterpenes and Evaluation of Their Selectivity for Solid TumorsGlyceraldehyde acetonide serves as a chiral glyoxal equivalent and a linchpin for the enantioselective synthesis of several acyclic polyhalogenated monoterpenes from the red algae Plocamium. Several of these compounds demonstrate selective toxicity towards solid-tumor cell lines over leukemia cell lines, as well as low-micromolar cytotoxicity towards the HCT-116 human colon carcinoma cell line.

Read more now


 

Carbon Nanofibers

Carbon Nanofibers Decorated with Molybdenum Disulfide Nanosheets: Synergistic Lithium Storage and Enhanced Electrochemical Performance

Fei Zhou, Dr. Sen Xin, Dr. Hai-Wei Liang, Lu-Ting Song and Prof. Dr. Shu-Hong Yu

Carbon Nanofibers Decorated with Molybdenum Disulfide Nanosheets: Synergistic Lithium Storage and Enhanced Electrochemical PerformanceCarbon nanofibers (CNFs) decorated with molybdenum disulfide sheets are fabricated by a facile hydrothermal process with low-cost, biomass-derived carbonaceous nanofibers as the supports. On reacting with lithium, the nanofibers undergo novel electrochemical processes that are triggered by a synergistic lithium storage effect, leading to enhanced cycling and rate performance of the lithium-ion battery.

Read more now


 

Nanoflakes

Hexagonal Transition-Metal Chalcogenide Nanoflakes with Pronounced Lateral Quantum Confinement

Dr. Pere Miró, Jae Hyo Han, Prof. Dr. Jinwoo Cheon and Prof. Dr. Thomas Heine

Hexagonal Transition-Metal Chalcogenide Nanoflakes with Pronounced Lateral Quantum ConfinementSix-sided flakes: Transition-metal dichalcogenide nanoflakes of composition MX2 (where M=Ti, Zr and Hf; X=S and Se) grow preferentially in equilateral hexagons and exhibit a pronounced lateral quantum confinement. The hexagonal shape arises from the charge location at the edges and vertices and the resulting Coulombic repulsion.

Read more now


 

Electrochromic Supercapacitors

Large-Scale Fabrication of Pseudocapacitive Glass Windows that Combine Electrochromism and Energy Storage

Peihua Yang, Peng Sun, Zhisheng Chai, Prof. Langhuan Huang, Dr. Xiang Cai, Prof. Shaozao Tan, Prof. Jinhui Song and Prof. Wenjie Mai

Large-Scale Fabrication of Pseudocapacitive Glass Windows that Combine Electrochromism and Energy StorageA pseudocapacitive glass window (15×15 cm2) is obtained by the deposition of WO3 on fluorine-doped tin oxide glass. Such smart pseudocapacitive glass windows show great potential in functioning as electrochromic windows and concurrently powering electronic devices, such as mobile phones or laptops.

Read more now


 

Antitumor Agents

A CXCR4-Targeted Site-Specific Antibody–Drug Conjugate

Dr. Sumith A. Kularatne, Dr. Vishal Deshmukh, Dr. Jennifer Ma, Dr. Virginie Tardif, Dr. Reyna K. V. Lim, Holly M. Pugh, Dr. Ying Sun, Anthony Manibusan, Aaron J. Sellers, Dr. Richard S. Barnett, Shailaja Srinagesh, Jane S. Forsyth, Dr. Wolf Hassenpflug, Dr. Feng Tian, Dr. Tsotne Javahishvili, Prof. Brunhilde Felding-Habermann, Prof. Brian R. Lawson, Dr. Stephanie A. Kazane and Prof. Peter G. Schultz

A CXCR4-Targeted Site-Specific Antibody–Drug ConjugateHitting the mark(er): A chemically defined anti-CXCR4–auristatin antibody–drug conjugate (ADC) was produced that selectively targets and eliminates CXCR4+ metastatic cancer cells in vitro and in vivo with no significant overt toxicity. Because the CXCR4 receptor is highly expressed in the majority of metastatic cancers, a CXCR4–auristatin ADC may be useful for the treatment of a variety of metastatic malignancies.

Read more now


 

Radical C[BOND]H Functionalization of Heteroarenes under Electrochemical Control

Dr. Alexander G. O'Brien, Dr. Akinobu Maruyama, Dr. Yasuhide Inokuma, Prof. Makoto Fujita, Prof. Phil S. Baran and Prof. Donna G. Blackmond

Radical C<img src="http://onlinelibrarystatic.wiley.com/undisplayable_characters/00f8ff.gif" alt="[BOND]" />H Functionalization of Heteroarenes under Electrochemical ControlElectrochemical reactions are shown to be effective for the C[BOND]H functionalization of a number of heterocyclic substrates that are recalcitrant to conventional peroxide radical initiation conditions and of interest in medicinal chemistry. Monitoring reaction progress under electrochemical conditions provides mechanistic insight into the C[BOND]H functionalization process.

Read more now


 

Carbon Dioxide

Differential Reduction of CO2 by Molybdenum and Vanadium Nitrogenases

Johannes G. Rebelein, Prof. Dr. Yilin Hu and Prof. Dr. Markus W. Ribbe

Differential Reduction of CO2 by Molybdenum and Vanadium NitrogenasesVanadium nitrogenase can reduce CO2 to CO, CD4, C2D4, and C2D6. Its ability to reduce CO2 to C2 hydrocarbons adds another important reaction to the catalytic spectrum of the vanadium nitrogenase, that is, a reaction that involves C[BOND]C coupling from CO2.

Read more now


 

Pyrrole Synthesis

Insertion of Nitriles into Zirconocene-1-aza-1,3-diene Complexes: Chemoselective Synthesis of N-H and N-Substituted Pyrroles

Shasha Yu, Meijun Xiong, Xin Xie and Prof. Yuanhong Liu

Insertion of Nitriles into Zirconocene-1-aza-1,3-diene Complexes: Chemoselective Synthesis of N-H and N-Substituted PyrrolesExercise control: N-H and N-substituted pyrroles can be prepared through the direct insertion of nitriles into zirconocene-1-aza-1,3-diene complexes and their subsequent acidic aqueous work-up. The outcome of the reaction depends on the relative stability and reactivity of the corresponding enamine–imine tautomers formed through the hydrolysis of the diazazirconacycles.

Read more now


 

Anion Complexation

Anion Complexation and The Hofmeister Effect

Ryan S. Carnegie, Corinne L. D. Gibb and Prof. Bruce C. Gibb

Anion Complexation and The Hofmeister EffectThe strength of association between the hydrophobic, concave binding site of a deep-cavity cavitand and the ClO4 ion is controlled by co-salts in a manner that follows the Hofmeister series. A competitive binding of the co-salt anion to the hydrophobic pocket and its counterion to the external carboxylate groups accounts for the observed changes in ClO4 affinity.

Read more now


 

Fragment-Based Drug Discovery

Exploring Weak Ligand–Protein Interactions by Long-Lived NMR States : Improved Contrast in Fragment-Based Drug Screening

Roberto Buratto, Daniele Mammoli, Dr. Elisabetta Chiarparin, Dr. Glyn Williams and Prof. Geoffrey Bodenhausen

Exploring Weak Ligand–Protein Interactions by Long-Lived NMR States : Improved Contrast in Fragment-Based Drug ScreeningLigands with an affinity for selected proteins can be screened very effectively by exploiting long-lived states (LLS) in NMR spectroscopy. This approach allows ligands with a wide range of affinities (10 nM<KD<12 mM) to be characterized. The LLS method was used to measure the dissociation constants of fragments that bind weakly to the ATP binding domain of heat shock protein Hsp90, a therapeutic target for cancer treatment.

Read more now


 

Natural Products

Forazoline A: Marine-Derived Polyketide with Antifungal In Vivo Efficacy

Thomas P. Wyche, Dr. Jeff S. Piotrowski, Dr. Yanpeng Hou, Doug Braun, Raamesh Deshpande, Sean McIlwain, Irene M. Ong, Chad L. Myers, Dr. Ilia A. Guzei, Dr. William M. Westler, Prof. Dr. David R. Andes and Prof. Dr. Tim S. Bugni

Forazoline A: Marine-Derived Polyketide with Antifungal In Vivo EfficacyA bit of structure: A novel antifungal natural product, forazoline A, was isolated from Actinomadura sp. The structure of forazoline A was elucidated by a combination of NMR spectroscopy, molecular modeling, and synthetic modifications. The compound demonstrated in vivo efficacy in a mouse model of Candida albicans. A chemical genomics approach suggested that forazoline A works through a new mechanism of action.

Read more now


 

Lithium-Ion Batteries

Organic Dicarboxylate Negative Electrode Materials with Remarkably Small Strain for High-Voltage Bipolar Batteries

Dr. Nobuhiro Ogihara, Tomomi Yasuda, Yoshihiro Kishida, Dr. Tetsu Ohsuna, Kaito Miyamoto and Dr. Nobuko Ohba

Organic Dicarboxylate Negative Electrode Materials with Remarkably Small Strain for High-Voltage Bipolar BatteriesCorridors of power: 2,6-Naphthalene dicarboxylate dilithium (Naph(COOLi)2), which has an organic–inorganic layered framework, shows reversible Li intercalation at a flat potential of 0.8 V. The layered framework is maintained during Li intercalation, and its volume change is only 0.33 %. An 8 V bipolar Naph(COOLi)2/LiNi0.5Mn1.5O4 cell with an Al current collector was constructed from only two cells connected in series.

Read more now


 

Organocatalysis

Enantioselective Synthesis of Piperidines through the Formation of Chiral Mixed Phosphoric Acid Acetals: Experimental and Theoretical Studies

Dr. Zhankui Sun, Grace A. Winschel, Prof. Dr. Paul M. Zimmerman and Prof. Dr. Pavel Nagorny

Enantioselective Synthesis of Piperidines through the Formation of Chiral Mixed Phosphoric Acid Acetals: Experimental and Theoretical StudiesA rich seam: An enantioselective chiral phosphoric acid-catalyzed cyclization of unsaturated acetals has been utilized for the synthesis of functionalized chiral piperidines. The chiral enol ether products of these cyclizations undergo subsequent in situ enantioenrichment. A new computational method was utilized to elucidate the mechanism and stereoselectivity of this transformation. Cbz=benzyloxycarbonyl; S=resolution.

Read more now


 

Mussel Adhesive

In Vivo Residue-Specific Dopa-Incorporated Engineered Mussel Bioglue with Enhanced Adhesion and Water Resistance

Byeongseon Yang, Dr. Niraikulam Ayyadurai, Prof. Hyungdon Yun, Prof. Yoo Seong Choi, Dr. Byeong Hee Hwang, Jun Huang, Dr. Qingye Lu, Prof. Hongbo Zeng and Prof. Hyung Joon Cha

In Vivo Residue-Specific Dopa-Incorporated Engineered Mussel Bioglue with Enhanced Adhesion and Water ResistanceEngineered mussel glue with a very high 3,4-dihydroxyphenylalanine (Dopa) content close to that of natural protein was created through in vivo residue-specific Dopa incorporation method in Escherichia coli. This bioglue exhibited strong adhesion and water-resistance, which shows great potential in underwater applications.

Read more now


 

Catalyst Stability

Engineering Catalyst Microenvironments for Metal-Catalyzed Hydrogenation of Biologically Derived Platform Chemicals

Thomas J. Schwartz, Robert L. Johnson, Javier Cardenas, Dr. Adam Okerlund, Prof. Nancy A. Da Silva, Prof. Klaus Schmidt-Rohr and Prof. James A. Dumesic

Engineering Catalyst Microenvironments for Metal-Catalyzed Hydrogenation of Biologically Derived Platform ChemicalsThe surface properties of supported metal hydrogenation catalysts are modified by the formation of microenvironments inside the catalyst pores and surrounding the metal nanoparticles. These microenvironments are derived from poly(vinyl alcohol) (PVA), and they are used to mitigate catalyst deactivation that is due to biogenic impurities.

Read more now


 

18F-Labeling

An Organotrifluoroborate for Broadly Applicable One-Step 18F-Labeling

Zhibo Liu, Maral Pourghiasian, Mark Alex Radtke, Joseph Lau, Dr. Jinhe Pan, Gemma M. Dias, Dr. Donald Yapp, Dr. Kuo-Shyan Lin, Prof. Dr. Francois Bénard and Prof. Dr. David M. Perrin

An Organotrifluoroborate for Broadly Applicable One-Step 18F-LabelingLike a postage stamp that neither alters a letter’s weight nor changes its contents or destination, a new zwitterionic trifluoroborate radiosynthon transforms complex molecules into 18F-tracers that are labeled in a single aqueous-phase step in high yield and at high specific radioactivity without HPLC purification.

Read more now


 

Carbonic Acid

Gas-Phase Preparation of Carbonic Acid and Its Monomethyl Ester

Dr. Hans Peter Reisenauer, M. Sc. J. Philipp Wagner and Prof. Dr. Peter R. Schreiner

Gas-Phase Preparation of Carbonic Acid and Its Monomethyl EsterThe matrix-isolation IR spectrum of carbonic acid generated through gas-phase pyrolysis of Boc2O (Boc=tert-butoxycarbonyl) or (tBuO)2CO unequivocally shows that the long-claimed identity of the gas phase above its α-polymorph is not carbonic acid, but rather the monomethyl ester, which was analogously prepared from MeOC(O)OtBu and identified in the gas phase for the first time.

Read more now


 

Bioconjugation

Dialdehydes Lead to Exceptionally Fast Bioconjugations at Neutral pH by Virtue of a Cyclic Intermediate

Pascal Schmidt, Dr. Linna Zhou, Kiril Tishinov, Kaspar Zimmermann and Prof. Dr. Dennis Gillingham

Dialdehydes Lead to Exceptionally Fast Bioconjugations at Neutral pH by Virtue of a Cyclic IntermediateFor aldehydes, 1+1=500: Dialdehydes react with O-alkylhydroxylamines at rates of 500 M−1 s−1 at neutral pH values in the absence of catalysts. The key to these conjugations is an unusually stable cyclic intermediate, which ultimately undergoes dehydration to yield an oxime. The application of this method in bioconjugations and a mechanistic interpretation are outlined.

Read more now


 

Ruthenium Pincer Complexes

Direct Catalytic Olefination of Alcohols with Sulfones

Dr. Dipankar Srimani, Dr. Gregory Leitus, Yehoshoa Ben-David and Prof. Dr. David Milstein

Direct Catalytic Olefination of Alcohols with SulfonesThe one-step olefination of alcohols with sulfones for the direct synthesis of terminal and internal olefins is catalyzed by ruthenium pincer complexes. Furthermore, performing the reaction with dimethyl sulfone under mild hydrogen pressure provides a one-step method for the replacement of alcohol hydroxy groups by methyl groups.

Read more now


 

Bioorthogonal Chemistry

Super-Resolution Imaging of Plasma Membrane Glycans

Sebastian Letschert, Dr. Antonia Göhler, Christian Franke, Nadja Bertleff-Zieschang, Elisabeth Memmel, Priv.-Doz. Dr. Sören Doose, Prof. Dr. Jürgen Seibel and Prof. Dr. Markus Sauer

Super-Resolution Imaging of Plasma Membrane GlycansGlycan spotting: Click chemistry and super-resolution imaging was used to visualize and quantify ManNAc-, GalNAc-, and O-GlcNAc-modified glycans in the plasma membrane of mammalian cells with single-molecule sensitivity (see image). The data demonstrate that a single cell may easily contain more than ten million glycans, which are homogeneously distributed and do not form clusters or nanodomains.

Read more now


 

Electrocatalysis

Controlling Selectivity in the Chlorine Evolution Reaction over RuO2-Based Catalysts

Kai S. Exner, Josef Anton, Timo Jacob and Herbert Over

Controlling Selectivity in the Chlorine Evolution Reaction over RuO2-Based CatalystsBeing selective: The selectivity in the industrially important Chlor-Alkali process has been elucidated on the microscopic level through a combination of DFT calculations and volcano plots. A single layer of TiO2(110) grown on RuO2(110) increases the selectivity between the chlorine and oxygen evolution reactions (CER and OER, respectively) by several orders of magnitude, while keeping the high activity for CER practically constant.

Read more now


 

SEARCH

SEARCH BY CITATION