Angewandte Chemie International Edition

Cover image for Vol. 54 Issue 32

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.

Carbohydrate Immunology

Chemical Synthesis Elucidates the Immunological Importance of a Pyruvate Modification in the Capsular Polysaccharide of Streptococcus pneumoniae Serotype 4

Dr. Claney L. Pereira, Andreas Geissner, Dr. Chakkumkal Anish and Prof. Dr. Peter H. Seeberger

Chemical Synthesis Elucidates the Immunological Importance of a Pyruvate Modification in the Capsular Polysaccharide of Streptococcus pneumoniae Serotype 4Unusually Protective. In the search for a glycan epitope for protection against Streptococcus pneumoniae serotype 4, total synthesis of the repeating unit (see structure) enabled the identification of pyruvate as a crucial determinant of immunogenicity. This lays the foundation for the development of a new antibacterial vaccine candidate against Streptococcus pneumoniae serotype 4.

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Light-Emitting Diodes

Waterproof Alkyl Phosphate Coated Fluoride Phosphors for Optoelectronic Materials

Dr. Hoang-Duy Nguyen, Dr. Chun Che Lin and Prof. Dr. Ru-Shi Liu

Waterproof Alkyl Phosphate Coated Fluoride Phosphors for Optoelectronic MaterialsThe moisture instability of fluoride phosphors has limited their application in optoelectronic devices. Their waterproof properties can be improved by a hydrophobic coating layer, such as an alkyl phosphate. The luminous efficacy of warm white-light-emitting diodes (WLEDs) based on such coated phosphors is remarkably stable even under high-humidity and high-temperature conditions.

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Perovskites

Rattling in the Quadruple Perovskite CuCu3V4O12

Dr. Yasuhide Akizuki, Dr. Ikuya Yamada, Dr. Koji Fujita, Kazuya Taga, Dr. Takateru Kawakami, Dr. Masaichiro Mizumaki and Prof. Katsuhisa Tanaka

Rattling in the Quadruple Perovskite CuCu3V4O12Oversize me: CuCu3V4O12 is synthesized using a high-pressure technique. This compound adopts the cubic A-site ordered perovskite-type structure (space group Imequation image) with a valence distribution of Cu2+Cu2+3V4+4O12. It has oversized icosahedral cages in which loosely bound A-site Cu2+ ions rattle with a characteristic temperature (Einstein temperature) of ΘE≈55 K. This is the first demonstration of rattling in perovskites.

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Organic Reductants

Pushing the Limits of Neutral Organic Electron Donors: A Tetra(iminophosphorano)-Substituted Bispyridinylidene

Samuel S. Hanson, Dr. Eswararao Doni, Kyle T. Traboulsee, Dr. Graeme Coulthard, Prof. Dr. John A. Murphy and Prof. Dr. C. Adam Dyker

Pushing the Limits of Neutral Organic Electron Donors: A Tetra(iminophosphorano)-Substituted BispyridinylideneUnlocking max potential: The four strongly π-donating iminophosphorano substituents of compound 1 impart an impressive redox potential of −1.70 V versus saturated calomel electrode (SCE) for the 12+/1 redox couple, and make 1 the first organic donor able to reduce malononitriles and diakylarenesulfonamides without photoexcitation.

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Imaging Probes

A Small-Molecule Probe for Selective Profiling and Imaging of Monoamine Oxidase B Activities in Models of Parkinson’s Disease

Dr. Lin Li, Dr. Cheng-Wu Zhang, Dr. Jingyan Ge, Linghui Qian, Bing-Han Chai, Prof. Dr. Qing Zhu, Prof. Dr. Jun-Seok Lee, Prof. Dr. Kah-Leong Lim and Prof. Dr. Shao Q. Yao

A Small-Molecule Probe for Selective Profiling and Imaging of Monoamine Oxidase B Activities in Models of Parkinson’s DiseaseSeeing is believing: A dual-purpose small-molecule activity-based probe (M2) was developed for imaging the activity of monoamine oxidase B (MAO-B). In situ proteome profiling and live-cell bioimaging of endogenous MAO-B activities from a variety of biological samples, including Parkinson’s disease models, can thus be carried out simultaneously.

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Hydrogen Storage System

Rechargeable Hydrogen Storage System Based on the Dehydrogenative Coupling of Ethylenediamine with Ethanol

Dr. Peng Hu, Yehoshoa Ben-David and Prof. Dr. David Milstein

Rechargeable Hydrogen Storage System Based on the Dehydrogenative Coupling of Ethylenediamine with EthanolIn support of the hydrogen economy: An efficient and simple homogeneous hydrogen carrier system was developed based on the dehydrogenative coupling of ethylenediamine with ethanol to form diacetylethylenediamine. The same ruthenium pincer catalyst is used for both hydrogen loading and unloading reactions.

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Biosynthesis

A Single Enzyme Transforms a Carboxylic Acid into a Nitrile through an Amide Intermediate

Micah T. Nelp and Prof. Vahe Bandarian

A Single Enzyme Transforms a Carboxylic Acid into a Nitrile through an Amide IntermediateDouble duty: In bacterial and archeal biosynthesis of 7-deazpurines, a single enzyme, ToyM, catalyzes the two-step conversion of the carboxylic acid 7-carboxy-7-deazaguanine (CDG) into the corresponding nitrile, 7-cyano-7-deazaguanine (preQ0). The mechanism of this unusual direct transformation proceeds via the adenylation of CDG. This activates it to form the amide intermediate 7-amido-7-deazaguanine (ADG), which is in turn activated to form the nitrile.

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Epoxidation Catalysis

Direct Epoxidation of Propylene over Stabilized Cu+ Surface Sites on Titanium-Modified Cu2O

Dr. Xiaofang Yang, Dr. Shyam Kattel, Ke Xiong, Dr. Kumudu Mudiyanselage, Dr. Sergei Rykov, Dr. Sanjaya D. Senanayake, Dr. José A. Rodriguez, Dr. Ping Liu, Dr. Dario J. Stacchiola and Prof. Dr. Jingguang G. Chen

Direct Epoxidation of Propylene over Stabilized Cu+ Surface Sites on Titanium-Modified Cu2OTi-ed up: Cu+ active sites on a Cu2O surface can be stabilized with TiOx by forming a mixed oxide, TiCuOx. The basicity of the surface-bound oxygen atoms thus decreases which inhibits combustion and promotes the formation of an oxametallacycle intermediate with propylene leading to higher selectivity for propylene epoxidation.

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Biosensors

An Activity-Based Probe for Studying Crosslinking in Live Bacteria

Dr. Samir Gautam, Dr. Taehan Kim, Dr. Takuji Shoda, Dr. Sounok Sen, Deeksha Deep, Ragini Luthra, Maria Teresa Ferreira, Prof. Dr. Mariana G. Pinho and Prof. Dr. David A. Spiegel

An Activity-Based Probe for Studying Crosslinking in Live BacteriaLinked in: A nontoxic fluorescent probe that mimics the peptidoglycan stem peptide can be used to install fluorophores at sites of crosslinking within the bacterial cell wall (see picture). The probe is specific for penicillin-binding protein 4 (PBP4) in Staphylococcus aureus, and thus allows visualization and relative quantification of PBP4-mediated crosslinking in this important human pathogen.

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Iminoborane

Encapsulating Inorganic Acetylene, HBNH, Using Flanking Coordinative Interactions

Anindya K. Swarnakar, Dr. Christian Hering-Junghans, Koichi Nagata, Dr. Michael J. Ferguson, Dr. Robert McDonald, Prof. Dr. Norihiro Tokitoh and Prof. Dr. Eric Rivard

Encapsulating Inorganic Acetylene, HBNH, Using Flanking Coordinative InteractionsLightning in a bottle: An adduct of the elusive parent “inorganic acetylene” HBNH was prepared from a main-group azide by means of a general process consisting of N2 loss and 1,2-hydrogen migration. The mechanism of this reaction was examined by calculations and isotope-labeling studies.

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Chemical Bonding

The Nature of Bonding between Argon and Mixed Gold–Silver Trimers

Armin Shayeghi, Prof. Dr. Roy L. Johnston, Dr. David M. Rayner, Prof. Dr. Rolf Schäfer and Dr. André Fielicke

The Nature of Bonding between Argon and Mixed Gold–Silver TrimersRelatively different: The evolution of noble-metal–noble-gas bonds in cationic argon complexes of mixed gold–silver trimers is studied considering the dependence on the composition of the clusters. The bond nature in the closed-shell molecules is probed by FIR-MPD spectroscopy supported by DFT calculations, reflecting the relativistic differences between gold and silver.

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Structure Elucidation

One Electron Makes Differences: From Heme {FeNO}7 to {FeNO}8

Bin Hu and Prof. Jianfeng Li

One Electron Makes Differences: From Heme {FeNO}7 to {FeNO}8Bioinorganic chemistry: The first X-ray single-crystal structure of a {FeNO}8 porphyrin complex [Co(Cp)2][Fe(TFPPBr8)(NO)] and the structure of the {FeNO}7 precursor [Fe(TFPPBr8)(NO)] are reported. [Fe(TFPPBr8)(NO)] shows a much more bent Fe[BOND]N[BOND]O angle (122.4(3)°) and longer Fe[BOND]NO and N[BOND]O bond distances than the nitrosyl iron(II) analogs (see picture).

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Aromaticity

Synthesis of a Tetrabenzotetraaza[8]circulene by a “Fold-In” Oxidative Fusion Reaction

Dr. Fengkun Chen, Yong Seok Hong, Dr. Soji Shimizu, Prof. Dr. Dongho Kim, Prof. Dr. Takayuki Tanaka and Prof. Dr. Atsuhiro Osuka

Synthesis of a Tetrabenzotetraaza[8]circulene by a “Fold-In” Oxidative Fusion ReactionA perfectly planar structure with a central cyclooctatetraene (COT) core that shows little alternation in the bond lengths is the main feature of tetrabenzotetraaza[8]circulene. This heterocirculene shows aromatic-like characteristics, such as a sharp absorption spectrum, a high fluorescence quantum yield, and a degenerate HOMO, thus suggesting the predominant contribution of an [8]radialene-like electronic system.

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Hybrid Polymers

Poly(p-phenylenediethynylene phosphane): A Phosphorus-Containing Macromolecule that Displays Blue Fluorescence Upon Oxidation

Benjamin W. Rawe and Prof. Dr. Derek P. Gates

Poly(p-phenylenediethynylene phosphane): A Phosphorus-Containing Macromolecule that Displays Blue Fluorescence Upon OxidationP-polymer brings light: A new phosphorus-containing macromolecule, PPYP, has been synthesized that features phosphorus atoms incorporated between phenylene alkynyl groups. PPYP selectively exhibits blue fluorescence (see picture) when oxidized at phosphorus and, therefore, is of potential interest for sensor applications.

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Carbene versus Carbenoid

Copper and Silver Carbene Complexes without Heteroatom-Stabilization: Structure, Spectroscopy, and Relativistic Effects

M. Sc. Matthias W. Hussong, Dipl.-Chem. Wilhelm T. Hoffmeister, Dr. Frank Rominger and Prof. Dr. Bernd F. Straub

Copper and Silver Carbene Complexes without Heteroatom-Stabilization: Structure, Spectroscopy, and Relativistic EffectsRelatively labile relatives: Isostructural Group 11 element carbene complexes have been prepared and characterized. Thermolability, deshielded carbene NMR spectroscopy signals, and bathochromic light absorption of the copper and silver complexes reflect their increased carbenoid character compared to the gold analogue, whose remarkable stability is explained by strong relativistic effects on gold′s valence shell.

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Nanotubes

General Formation of MxCo3−xS4 (M=Ni, Mn, Zn) Hollow Tubular Structures for Hybrid Supercapacitors

Dr. Yu Ming Chen, Dr. Zhen Li and Prof. Xiong Wen (David) Lou

General Formation of MxCo3−xS4 (M=Ni, Mn, Zn) Hollow Tubular Structures for Hybrid SupercapacitorsHollow tubular structures of MxCo3−xS4 (M=Ni, Mn, Zn) can be synthesized with controllable composition by using a simple soft polymeric template (polyacrylonitrile; PAN). The as-prepared mixed-metal sulfide nanotubes exhibit unprecedented electrochemical performance as electrode materials for hybrid supercapacitors.

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Cross-Coupling

Iron-Catalyzed Cross-Coupling of Alkenyl Acetates

M.Sc. Dominik Gärtner, Dr. André Luiz Stein, Dr. Sabine Grupe, Dr. Johannes Arp and Prof. Dr. Axel Jacobi von Wangelin

Iron-Catalyzed Cross-Coupling of Alkenyl AcetatesIron clad: Acetates are underutilized electrophiles in metal-catalyzed cross-coupling reactions because of the strong alkenyl C[BOND]O bond and their propensity to engage in unwanted reactions. Combination of a ligand-free low-valent Fe catalyst with nucleophilic organomagnesium reagents, low temperature, and short reaction times results in highly selective cross-couplings with alkenyl acetates.

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CO2-Based Materials

Construction of Versatile and Functional Nanostructures Derived from CO2-based Polycarbonates

Yanyan Wang, Jingwei Fan and Prof. Donald J. Darensbourg

Construction of Versatile and Functional Nanostructures Derived from CO2-based PolycarbonatesA two step, one-pot synthesis of an amphiphilic triblock polycarbonate from CO2 and propylene oxide is described. The poly(propylene carbonate) diols produced in the first step serve as macroinitiators in the subsequent allyl glycidyl ether/CO2 coupling reaction leading to self-assembled triblock PC nanoparticles following postmodification by thiol–ene click chemistry.

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Methanol Economy

Bioinduced Room-Temperature Methanol Reforming

M.Sc. Leo E. Heim, Dipl.-Chem. Daniel Thiel, Christian Gedig, Priv.-Doz. Dr. Jan Deska and Priv.-Doz. Dr. Martin H. G. Prechtl

Bioinduced Room-Temperature Methanol ReformingImitating natures approach for nucleophile-activated formaldehyde dehydrogenation: Air-stable ruthenium complexes are catalysts for the dehydrogenation of formaldehyde hydrate as well as for the transfer hydrogenation to unsaturated organic substrates. In combination with an oxidase-mediated activation of methanol, an artificial methylotrophic in vitro metabolism provides hydrogen gas in a room-temperature methanol-reforming pathway.

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Drug Delivery

Single-Vehicular Delivery of Antagomir and Small Molecules to Inhibit miR-122 Function in Hepatocellular Carcinoma Cells by using “Smart” Mesoporous Silica Nanoparticles

Dr. Changmin Yu, Linghui Qian, Dr. Mahesh Uttamchandani, Dr. Lin Li and Prof. Dr. Shao Q. Yao

Single-Vehicular Delivery of Antagomir and Small Molecules to Inhibit miR-122 Function in Hepatocellular Carcinoma Cells by using “Smart” Mesoporous Silica NanoparticlesDouble inhibition: A smart drug-delivery system, constructed by using antagomir-capped mesoporous silica nanoparticles (MSNs), is capable of simultaneous target-triggered release of an antagomir and a hydrophobic small molecule microRNA inhibitor in Huh7 cells to achieve combination inhibition of endogenous miR-122.

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Silicon Compounds

From Silylone to an Isolable Monomeric Silicon Disulfide Complex

Dr. Yun Xiong, Dr. Shenglai Yao, Dr. Robert Müller, Prof. Dr. Martin Kaupp and Prof. Dr. Matthias Driess

From Silylone to an Isolable Monomeric Silicon Disulfide ComplexFamily catching: The elusive monomeric silicon disulfide SiS2 could be stabilized in the chelating pocket of a bis-N-heterocyclic carbene (bis-NHC) donor, resulting in the first silicon disulfide complex 1. Compound 1 reacts with GaCl3 to form the corresponding (bis-NHC)Si([DOUBLE BOND]S)S[RIGHTWARDS ARROW]GaCl3 adduct 3 which is also accessible from the unprecedented silylone[RIGHTWARDS ARROW]GaCl3 adduct 4.

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Lithium-Ion Batteries

A New Perspective on Li–SO2 Batteries for Rechargeable Systems

Hee-Dae Lim, Hyeokjun Park, Hyungsub Kim, Jinsoo Kim, Byungju Lee, Youngjoon Bae, Hyeokjo Gwon and Prof. Kisuk Kang

A New Perspective on Li–SO2 Batteries for Rechargeable SystemsEnergy storage: Although Li–SO2 batteries have been used as primary batteries to date, the feasibility of a rechargeable Li–SO2 battery is demonstrated based on the reversible formation and decomposition of the solid product Li2S2O4 (see picture). The observed energy efficiency of the Li–SO2 system is significantly better than that of the Li–O2 system.

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Functional Nanostructures

A Universal Approach to Ultrasmall Magneto-Fluorescent Nanohybrids

Artur Feld, Jan-Philip Merkl, Dr. Hauke Kloust, Dr. Sandra Flessau, Dr. Christian Schmidtke, Christopher Wolter, Dr. Johannes Ostermann, Michael Kampferbeck, Robin Eggers, Prof. Dr. Alf Mews, Dr. Theo Schotten and Prof. Dr. Horst Weller

A Universal Approach to Ultrasmall Magneto-Fluorescent NanohybridsMatching unlikely pairs: In a two-step procedure, iron oxide nanocrystals were initially encapsulated in a polystyrene (PS) shell and subsequently used as beads for a controlled assembly of elongated quantum dots/quantum rods (QDQRs) The fluorescence of the QDQRs and magnetism of iron oxide were perfectly preserved in the resulting nanohybrids.

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DNA Structures

Post-Assembly Stabilization of Rationally Designed DNA Crystals

Jiemin Zhao, Arun Richard Chandrasekaran, Qian Li, Xiang Li, Ruojie Sha, Prof. Nadrian C. Seeman and Prof. Chengde Mao

Post-Assembly Stabilization of Rationally Designed DNA CrystalsAdded stability: Owing to weak inter-unit cohesion, self-assembled DNA crystals tend to be fragile. Such nanostructures can be effectively stabilized by the addition of a molecule that binds to the cohesive sites and stabilizes the inter-unit interactions. Whereas the original DNA crystals are only stable in solutions of high ionic strength (e.g., ≥1.2 M (NH4)2SO4), the stabilized crystals are stable at much lower ionic strengths.

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Heteroacenes

Fused Thiophene-Pyrrole-Containing Ring Systems up to a Heterodecacene

Christoph Wetzel, Eduard Brier, Astrid Vogt, Dr. Amaresh Mishra, Dr. Elena Mena-Osteritz and Prof. Dr. Peter Bäuerle

Fused Thiophene-Pyrrole-Containing Ring Systems up to a HeterodecaceneA bunch of fives: A new family of fused thiophene-pyrrole-containing S,N-heteroacenes with extended π-conjugation was synthesized (S yellow, N blue, C gray, H white). The characterization of optical and redox properties showed valuable structure–property relationships.

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Polypharmacology

Fragment-Based Discovery of a Dual pan-RET/VEGFR2 Kinase Inhibitor Optimized for Single-Agent Polypharmacology

Brendan Frett, Francesca Carlomagno, Maria Luisa Moccia, Annalisa Brescia, Giorgia Federico, Valentina De Falco, Brittany Admire, Zhongzhu Chen, Wenqing Qi, Massimo Santoro and Hong-yu Li

Fragment-Based Discovery of a Dual pan-RET/VEGFR2 Kinase Inhibitor Optimized for Single-Agent PolypharmacologyDual inhibition: A kinase-directed fragment-based screen identified a novel active pharmacophore for the RET tyrosine kinase (RET=rearranged during transfection). In a medicinal chemistry/polypharmacology approach, Pz-1 was found to be a dual pan-RET/VEGFR2 inhibitor and able to simultaneously treat the parenchyma (RET) and stroma (VEGFR2) of RET-driven tumors in cell and xenograft models.

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Metal–Metal Bonds

A Mixed-Valence Tri-Zinc Complex, [LZnZnZnL] (L=Bulky Amide), Bearing a Linear Chain of Two-Coordinate Zinc Atoms

Jamie Hicks, Emma J. Underhill, Dr. Christos E. Kefalidis, Prof. Laurent Maron and Prof. Cameron Jones

A Mixed-Valence Tri-Zinc Complex, [LZnZnZnL] (L=Bulky Amide), Bearing a Linear Chain of Two-Coordinate Zinc AtomsForm an orderly queue! Reduction of an extremely bulky amido (L*) zinc bromide complex, [L*ZnBr] with a magnesium(I) dimer yields the formally zinc(0) complex, [L*ZnMg(MesNacnac)], which contains the first example of an unsupported Zn[BOND]Mg bond. Its subsequent reaction with ZnBr2 affords the unprecedented mixed-valence, linear tri-zinc complex, [L*ZnIZn0ZnIL*] (see picture).

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Synthetic Methods

Enantioselective α-Alkylation of Aldehydes by Photoredox Organocatalysis: Rapid Access to Pharmacophore Fragments from β-Cyanoaldehydes

Eric R. Welin, Dr. Alexander A. Warkentin, Dr. Jay C. Conrad and Prof. Dr. David W. C. MacMillan

Enantioselective α-Alkylation of Aldehydes by Photoredox Organocatalysis: Rapid Access to Pharmacophore Fragments from β-CyanoaldehydesA combination of photoredox catalysis and enamine catalysis has enabled the development of an enantioselective cyanoalkylation of aldehydes. This synergistic catalysis protocol makes possible the coupling of two highly versatile yet orthogonal functionalities.

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Pincer Complexes

Reversible α-Hydrogen and α-Alkyl Elimination in PC(sp3)P Pincer Complexes of Iridium

Dr. Klara J. Jonasson, Dr. Alexey V. Polukeev, Dr. Rocío Marcos, Prof. Mårten S. G. Ahlquist and Prof. Ola F. Wendt

Reversible α-Hydrogen and α-Alkyl Elimination in PC(sp3)P Pincer Complexes of IridiumAn iridium pincer complex undergoes reversible α-alkyl elimination. Under certain conditions, this fundamentally new process for C(sp3)[BOND]C(sp3) bond cleavage has a low barrier that is comparable with that of well known α-hydrogen elimination reactions. Kinetic studies, activation parameters, and DFT calculations are also discussed.

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Nitrogen Fixation

Metal-Mediated Production of Isocyanates, R3EN[DOUBLE BOND]C[DOUBLE BOND]O from Dinitrogen, Carbon Dioxide, and R3ECl

Andrew J. Keane, Wesley S. Farrell, Brendan L. Yonke, Peter Y. Zavalij and Prof. Lawrence R. Sita

Metal-Mediated Production of Isocyanates, R3EN<img src="http://onlinelibrarystatic.wiley.com/undisplayable_characters/00f8fe.gif" alt="[DOUBLE BOND]" />C<img src="http://onlinelibrarystatic.wiley.com/undisplayable_characters/00f8fe.gif" alt="[DOUBLE BOND]" />O from Dinitrogen, Carbon Dioxide, and R3EClTandem fixation: A highly efficient and versatile chemical cycle has been developed for the production of isocyanates through the molecular fixation of N2, CO2, and R3ECl (E=C, Si and Ge). Key steps include a simultaneous nitrene-group transfer and oxygen-atom transfer.

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Non-ribosomal Peptides

Structure Elucidation and Activity of Kolossin A, the D-/L-Pentadecapeptide Product of a Giant Nonribosomal Peptide Synthetase

Prof. Dr. Helge B. Bode, Dr. Alexander O. Brachmann, Dr. Kirtikumar B. Jadhav, Dr. Lydia Seyfarth, Dipl.-Chem. Christina Dauth, Dr. Sebastian W. Fuchs, Dr. Marcel Kaiser, Dr. Nick R. Waterfield, Dipl.-Phys. Holger Sack, Prof. Dr. Stefan H. Heinemann and Prof. Dr. Hans-Dieter Arndt

Structure Elucidation and Activity of Kolossin A, the <span class="smallCaps">D</span>-/<span class="smallCaps">L</span>-Pentadecapeptide Product of a Giant Nonribosomal Peptide SynthetaseSleeping giant: A 1.8 MDa nonribosomal peptide synthetase (NRPS) was identified in the entomopathogenic bacterium Photorhabdus luminescens and its production was activated. Its 15-mer D-/ L-peptide product kolossin A was structurally characterized by combining genomic analysis of the silent gene cluster, molecular biology, LC–MS, and total synthesis. A stereoisomer of kolossin A was found to be active against the pathogen that causes African sleeping sickness.

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Nanoparticle Morphology

Sequential Anion and Cation Exchange Reactions for Complete Material Transformations of Nanoparticles with Morphological Retention

James M. Hodges, Karel Kletetschka, Julie L. Fenton, Carlos G. Read and Prof. Raymond E. Schaak

Sequential Anion and Cation Exchange Reactions for Complete Material Transformations of Nanoparticles with Morphological RetentionComplete transformation: Metal oxide nanocrystals can be transformed into chalcogenides of different metals using sequential anion and cation exchange reactions. The products retain the morphology of the starting material, but contain entirely different elemental components. Morphology and composition control in colloidal nanocrystal synthesis are thus fully decoupled.

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Plasmonics

Black Gold: Plasmonic Colloidosomes with Broadband Absorption Self-Assembled from Monodispersed Gold Nanospheres by Using a Reverse Emulsion System

Dilong Liu, Dr. Fei Zhou, Cuncheng Li, Tao Zhang, Honghua Zhang, Prof. Weiping Cai and Prof. Yue Li

Black Gold: Plasmonic Colloidosomes with Broadband Absorption Self-Assembled from Monodispersed Gold Nanospheres by Using a Reverse Emulsion SystemBlack colloidosomes: 3D hollow plasmonic colloidosomes (see picture) composed of hexagonal close-packed gold nanospheres were self-assembled by a new reverse water-in-1-butanol emulsion system. These gold colloidosomes display a strong plasmonic coupling effect with broadband light absorption, show black color intrinsically, and are therefore denoted as black gold.

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Colloidal Crystals

Photonic Crystals with a Reversibly Inducible and Erasable Defect State Using External Stimuli

Mao Chen, Yapeng Zhang, Siyu Jia, Lin Zhou, Prof. Dr. Ying Guan and Prof. Dr. Yongjun Zhang

Photonic Crystals with a Reversibly Inducible and Erasable Defect State Using External StimuliArtificial defects: Doped microgel colloidal crystals were facilely assembled from two microgels with the same size. A defect state in the crystals could be reversibly induced and erased by external stimuli (see picture).

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Near-Infrared Luminescence

The Radiative Lifetime in Near-IR-Luminescent Ytterbium Cryptates: The Key to Extremely High Quantum Yields

M. Sc. Christine Doffek and Prof. Dr. Michael Seitz

The Radiative Lifetime in Near-IR-Luminescent Ytterbium Cryptates: The Key to Extremely High Quantum YieldsGenerating a warm glow indeed: By a combination of conventional optimization strategies with a new approach, near-IR-emissive ytterbium cryptates with unprecedented photoluminescence quantum yields of up to 12 % have been realized. The key to these successful luminophores is the judicious chemical design that makes the metal-centered emissive transition much more competitive with respect to quenching processes.

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Homogeneous Catalysis

An Aluminum Hydride That Functions like a Transition-Metal Catalyst

Prof. Zhi Yang, Dr. Mingdong Zhong, Dr. Xiaoli Ma, Dr. Susmita De, M. Sc. Chakkittakandiyil Anusha, Dr. Pattiyil Parameswaran and Prof. Herbert W. Roesky

An Aluminum Hydride That Functions like a Transition-Metal CatalystCanned catalysis: The aluminum hydride [LAlH(OTf)] has an excellent catalytic activity both in the hydroboration and the addition of trimethylsilyl cyanide (TMSCN) to aldehydes and ketones. The compound was synthesized by the reaction of [LAlH2] (L=HC(CMeNAr)2, Ar=2,6-iPr2C6H3) with MeOTf (Tf=SO2CF3). Theoretical calculations show that the catalyst initially acts as a hydride donor to the carbonyl group. HBPin=pinacolborane.

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CO Reduction

Reductive Cleavage of Carbon Monoxide by a Disilenide

Dr. Moumita Majumdar, Dipl.-Chem. Isabell Omlor, MSc Cem B. Yildiz, Prof. Dr. Akin Azizoglu, Dr. Volker Huch and Prof. Dr. David Scheschkewitz

Reductive Cleavage of Carbon Monoxide by a DisilenideHidden powers: Lithium disilenide reductively cleaves the strongest bond in chemistry, the C[TRIPLE BOND]O bond of carbon monoxide, at room temperature. A key step in the Fischer–Tropsch process is reiterated by an anionic molecular main-group system with Si[DOUBLE BOND]Si bonds. The mechanism is elucidated by DFT calculations and model reactions with Group 6 hexacarbonyls.

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Iridium Catalysis

The Retro-Hydroformylation Reaction

Dr. Shuhei Kusumoto, Toshiumi Tatsuki and Prof. Dr. Kyoko Nozaki

The Retro-Hydroformylation ReactionThe reverse reaction of hydroformylation, a so-called retro-hydroformylation, has been developed. In the presence of an iridium catalyst, alkenes were obtained from aliphatic aldehydes in up to 91 % yield along with the quantitative evolution of synthesis gas. Mechanistic studies suggest that this reaction indeed proceeds by a retro-hydroformylation mechanism.

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Antiproliferation

Small-Molecule-Mediated Degradation of the Androgen Receptor Through Hydrophobic Tagging

Dr. Jeffrey L. Gustafson, Dr. Taavi K. Neklesa, Carly S. Cox, Dr. Anke G. Roth, Dr. Dennis L. Buckley, Dr. Hyun Seop Tae, Dr. Thomas B. Sundberg, D. Blake Stagg, Dr. John Hines, Prof. Donald P. McDonnell, Dr. John D. Norris and Prof. Craig M. Crews

Small-Molecule-Mediated Degradation of the Androgen Receptor Through Hydrophobic TaggingMaking the problem go away: Most prostate tumor growth is driven by the action of the androgen receptor (AR). Resistance to current chemotherapies for prostate cancer can occur when the androgen receptor is either overexpressed or mutated. Coupling of an AR agonist to an adamantyl “hydrophobic tag” resulted in a molecule that induces AR degradation, even in drug-resistant prostate tumor cells.

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Nanobioanalysis

Real-time Monitoring of Discrete Synaptic Release Events and Excitatory Potentials within Self-reconstructed Neuro-muscular Junctions

Yu-Tao Li, Shu-Hui Zhang, Xue-Ying Wang, Xin-Wei Zhang, Dr. Alexander I. Oleinick, Prof. Dr. Irina Svir, Prof. Dr. Christian Amatore and Prof. Dr. Wei-Hua Huang

Real-time Monitoring of Discrete Synaptic Release Events and Excitatory Potentials within Self-reconstructed Neuro-muscular JunctionsA microfluidic chip was developed taking advantage of a carbon fiber nanoelectrodes (CFNE) and a robust platform for real-time monitoring of single intra-synaptic vesicular release events and of the subsequent generation of postsynaptic membrane excitatory potential (EJP) signals. By using this chip, the first in situ measurements of synaptic transmission in neuro-muscular mimics are reported.

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