Angewandte Chemie International Edition

Cover image for Vol. 53 Issue 17

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, 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.

Synthetic Methods

Organocatalytic Atroposelective Aldol Condensation: Synthesis of Axially Chiral Biaryls by Arene Formation

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Achim Link, Christof Sparr*

Head-turning! An organocatalytic atroposelective aldol condensation to tri-ortho-substituted biaryls is described. Key to the process is an efficient transfer of the stereochemical information of a secondary amine catalyst into the axis of chirality of binaphthyl products. The reaction proceeds analogous to the aromatic polyketide biosynthesis and is distinct in its initiation by virtue of dienamine formation. This method allows for the synthesis of axially chiral biaryls with remarkable atropo[shy]selectivity of up to e.r. 99:1.

Coming soon.


 

C(sp3)–H Activation

Palladium-Catalyzed C(sp3)–H Activation: A Facile Method for the Synthesis of 3,4-Dihydroquinolinone Derivatives

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Jia-Xuan Yan, Hu Li, Xiang-Wei Liu, Jiang-Ling Shi, Xin Wang, Zhang-Jie Shi*

3,4-Dihydroquinolinones were synthesized by the palladium-catalyzed, oxidative-addition-initiated activation and arylation of inert C(sp3)–H bonds. Pd(OAc)2 and P(o-tol)3 were used as the catalyst and ligand, respectively, to improve the efficiency of the reaction. A further advantage of this reaction is that it could be performed in air.

Published online, DOI: 10.1002/anie.201402562 – Read now


 

Mixed-Oxide Catalysts

Stabilization of Catalytically Active Cu+ Surface Sites on Titanium–Copper Mixed-Oxide Films

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Ashleigh E. Baber, Xiaofang Yang, Hyun You Kim, Kumudu Mudiyanselage, Markus Soldemo, Jonas Weissenrieder, Sanjaya D. Senanayake, Abdullah Al-Mahboob, Jerzy T. Sadowski, Jaime Evans, José A. Rodriguez, Ping Liu, Friedrich M. Hoffmann, Jingguang G. Chen, Darío J. Stacchiola*

Positively active: Copper oxide based structures were the first that could catalyze the oxidation of CO at room temperature. Their deactivation, however, is facile, because the required Cu+ state cannot be preserved under the reaction conditions. The addition of the right amount of titanium leads to mixed CuTiOx films that are thermally and chemically stable and more active CO oxidation catalysts than pure copper oxide materials.

Published online, DOI: 10.1002/anie.201402435 – Read now


 

Polyvalent Inhibitors

Design of Monodisperse and Well-Defined Polypeptide-Based Polyvalent Inhibitors of Anthrax Toxin

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Sanket Patke, Mohan Boggara, Ronak Maheshwari, Sunit K. Srivastava, Manish Arha, Marc Douaisi, Jacob T. Martin, Ian B. Harvey, Matthew Brier, Tania Rosen, Jeremy Mogridge, Ravi S. Kane*

Quantity and spacing: A protein-engineering approach was designed to develop monodisperse polyvalent molecules based on tandem-repeat polypeptide scaffolds. This approach allowed for precise control over ligand spacing and valency of the polyvalent molecules. This approach was applied to develop potent inhibitors of anthrax lethal toxin.

Published online, DOI: 10.1002/anie.201400870 – Read now


 

Solid-Phase Synthesis

Flow-Through Synthesis on Teflon-Patterned Paper To Produce Peptide Arrays for Cell-Based Assays

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Frédérique Deiss, Wadim L. Matochko, Natasha Govindasamy, Edith Y. Lin, Ratmir Derda*

On the same page: The patterned deposition of Teflon on paper creates barriers resistant to organic solvents. The solvents confined by the pattern flow through the paper at a controlled flow-rate, which permits the flow-through synthesis of 96 peptides in parallel on one sheet of paper. The resulting peptide arrays can be used to perform cell-based assays and discover 3D materials that support cell adhesion and growth.

Published online, DOI: 10.1002/anie.201402037 – Read now


 

Porous Cage Catenanes

A Shape-Persistent Quadruply Interlocked Giant Cage Catenane with Two Distinct Pores in the Solid State

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Gang Zhang, Oliver Presly, Fraser White, Iris M. Oppel, Michael Mastalerz*

Two is better than one: During the crystallization of a giant shape-persistent organic cage compound, a dimeric catenated structure is formed by a 96-fold condensation reaction of 40 molecular subunits. The crystals of the molecular catenane contain one intrinsic mesopore (2.0 nm) and one extrinsic micropore (1.3 nm).

Published online, DOI: 10.1002/anie.201400285 – Read now


 

Water Oxidation

A Molecular Approach to Self-Supported Cobalt-Substituted ZnO Materials as Remarkably Stable Electrocatalysts for Water Oxidation

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Johannes Pfrommer, Michael Lublow, Anahita Azarpira, Caren Göbel, Marcel Lücke, Alexander Steigert, Martin Pogrzeba, Prashanth W. Menezes, Anna Fischer*, Thomas Schedel-Niedrig*, Matthias Driess*

To be self-made: A cobalt-substituted zinc oxide (Co:ZnO) precatalyst was synthesized by low-temperature solvolysis of molecular heterobimetallic Co4−xZnxO4 (x=1–3) precursors. Electrophoretic deposition onto fluorinated tin oxide (FTO) electrodes leads, after oxidative conditioning, to an amorphous self-supported water-oxidation electrocatalyst that performs at very low overpotentials and with high current density for several hours.

Coming soon.


 

Protein Aggregation

Co-existence of Two Different α-Synuclein Oligomers with Different Core Structures Determined by Hydrogen/Deuterium Exchange Mass Spectrometry

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Wojciech Paslawski, Simon Mysling, Karen Thomsen, Thomas J. D. Jørgensen*, Daniel E. Otzen*

On-pathway or off-pathway? α-Synuclein oligomers are widely accepted to be cytotoxic species in Parkinson´s disease. There is debate as to whether they are intermediate species of fibril formation or the distinct end product of aggregation. Data indicate that both are correct and two different types of α-synuclein oligomers are formed: one that can be elongated by monomers and form fibrils and a second that stacks together to form more amorphous structures.

Published online, DOI: 10.1002/anie.201400491 – Read now


 

Organic–Inorganic Hybrid Materials

Engineering Multifunctional Capsules through the Assembly of Metal–Phenolic Networks

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Junling Guo, Yuan Ping, Hirotaka Ejima, Karen Alt, Mirko Meissner, Joseph J. Richardson, Yan Yan, Karlheinz Peter, Dominik von Elverfeldt, Christoph E. Hagemeyer, Frank Caruso*

Multifunctional capsules: A common plant phenolic compound, tannic acid, can be used to coordinate a variety of metals through a one-step assembly process, thereby yielding a broad library of metal–phenolic network (MPN; see picture) capsules. The properties of the MPN capsules are determined by the coordinated metals.

Published online, DOI: 10.1002/anie.201311136 – Read now


 

Fluorescent Dyes

Geminate Recombination as a Photoprotection Mechanism for Fluorescent Dyes

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Phil Holzmeister, Andreas Gietl, Philip Tinnefeld*

Single-molecule spectroscopy reveals a new mechanism for diffusion-limited photoprotection. Geminate recombination after reduction of organic dyes by thiols enhances photostabilization by avoiding the buildup of photobleaching intermediates such as photo-oxidized states. Stable and long-lasting fluorescence can be achieved in combination with ROXS buffers.

Published online, DOI: 10.1002/anie.201310300 – Read now


 

Nanoporous Graphene

High-Quality Three-Dimensional Nanoporous Graphene

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Yoshikazu Ito, Yoichi Tanabe, H.-J. Qiu, Katsuaki Sugawara, Satoshi Heguri, Ngoc Han Tu, Khuong Kim Huynh, Takeshi Fujita, Takashi Takahashi, Katsumi Tanigaki, Mingwei Chen*

A nickel for your graphene: The title material was synthesized by chemical vapor deposition using nanoporous nickel. The 3D nanoporous graphene preserves 2D electronic properties, such as high electron mobility and massless Dirac fermions.

Published online, DOI: 10.1002/anie.201402662 – Read now


 

Asymmetric Catalysis

Construction of Quaternary Stereogenic Carbon Centers through Copper-Catalyzed Enantioselective Allylic Cross-Coupling with Alkylboranes

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Kentaro Hojoh, Yoshinori Shido, Hirohisa Ohmiya*, Masaya Sawamura*

The SN2'-type: A combination of a chiral CuI/L* catalyst system and EtOK enabled the enantioselective SN2'-type allylic cross-coupling between alkylboranes and γ,γ-disubstituted primary allyl chlorides. The reaction generates quaternary carbon stereogenic centers bearing three sp3-alkyl groups and a vinyl group. A reaction pathway involving addition/elimination of a neutral alkylcopper(I) species is proposed.

Published online, DOI: 10.1002/anie.201402386 – Read now


 

Solar Cells

Constructing 3D Branched Nanowire Coated Macroporous Metal Oxide Electrodes with Homogeneous or Heterogeneous Compositions for Efficient Solar Cells

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Wu-Qiang Wu, Yang-Fan Xu, Hua-Shang Rao, Hao-Lin Feng, Cheng-Yong Su, Dai-Bin Kuang*

Wired for light: A versatile method allows the preparation of nanowire-coated macroporous material based homo- or heterogeneous metal oxide composite electrodes (TiO2–TiO2, SnO2–TiO2, and Zn2SnO4–TiO2). Dye-sensitized solar cells based on macroporous TiO2/TiO2 nanowire homogeneous electrode show an impressive conversion efficiency as high as 9.51 %, which is much higher than those of pure macroporous material based photoelectrodes used up to date.

Published online, DOI: 10.1002/anie.201402371 – Read now


 

Oligomer Growth

Controlled Electropolymerization of Ruthenium(II) Vinylbipyridyl Complexes in Mesoporous Nanoparticle Films of TiO2

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Zhen Fang, Shahar Keinan, Leila Alibabaei, Hanlin Luo, Akitaka Ito, Thomas J. Meyer*

Growth on the surface: Ruthenium(II) vinylpolypyridyl assemblies within the cavities of mesoporous nanoparticle TiO2 films have been grown from the surface by stepwise, electrochemically controlled radical polymerization. This polymerization was monitored by cyclic voltammetry as well as UV/Vis and X-ray photoelectron spectroscopy.

Published online, DOI: 10.1002/anie.201402309 – Read now


 

Alkene Difunctionalization

Arylphosphonylation and Arylazidation of Activated Alkenes

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Wangqing Kong, Estíbaliz Merino, Cristina Nevado*

Radical difunctionalization: The addition of heteroatom-centered radicals to the double bond of arylsulfonyl acrylamides furnishes alkyl radical intermediates. A reaction cascade is then triggered so that α-aryl-β-heterofunctionalized amides with a quaternary stereocenter are obtained by the simultaneous formation of C–C and C–P/C–N bonds across the double bond. Heterofunctionalized oxindoles can also be synthesized.

Published online, DOI: 10.1002/anie.201311241 – Read now


 

C–S Bond Formation

Gold-Catalyzed Intermolecular C–S Bond Formation: Efficient Synthesis of α-Substituted Vinyl Sulfones

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Yumeng Xi, Boliang Dong, Edward J. McClain, Qiaoyi Wang, Tesia L. Gregg, Novruz G. Akhmedov, Jeffrey L. Petersen, Xiaodong Shi*

Less basic, less hindered: The gold-catalyzed intermolecular Markovnikov addition of sulfinic acids to terminal alkynes has been achieved through the use of a bimetallic gold/gallium catalyst system. Various α-substituted vinyl sulfones were efficiently synthesized. A one-pot synthesis that starts from the bench-stable sodium sulfinates was also developed (DCE=1,2-dichloroethane).

Published online, DOI: 10.1002/anie.201310142 – Read now


 

N-Heterocyclic Carbenes

Fusing N-Heterocyclic Carbenes with Carborane Anions

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Ahmad El-Hellani, Vincent Lavallo*

Three in one: A novel family of polyanionic N-heterocyclic carbene–lithium adducts are reported, that feature two N-bonded weakly coordinating carborane anions. Judicious choice of base allows the selective deprotonation of an anionic imidazolium to form either a normal C2 or an abnormal C5 imidazolylidene. When treated with nBuLi the monoanionic imidazolium produces a doubly deprotonated trianionic C2,C5 dilithium complex.

Published online, DOI: 10.1002/anie.201402445 – Read now


 

Gene Expression

Bidirectional Regulation of mRNA Translation in Mammalian Cells by Using PUF Domains

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Jicong Cao, Manish Arha, Chaitanya Sudrik, David V. Schaffer*, Ravi S. Kane*

One way or another: A genetically encoded system based on the RNA binding domain of PUF proteins was developed for the posttranscriptional regulation of gene expression. The PUF domain was used to tether a translational activation domain (eIF4E) to enhance translation. Alternatively, the PUF domain alone could be used to repress translation. The expression of a reporter could be varied by over 17-fold by using PUF-based activators and repressors.

Published online, DOI: 10.1002/anie.201402095 – Read now


 

Gold Carbenoids

Structure of a Reactive Gold Carbenoid

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Günter Seidel, Alois Fürstner*

Call me "carbenoid": No signs of significant Au–C double-bond character, but many indications for charge density at carbon distinguish the structure of an only modestly "stabilized" gold carbenoid in the solid state. Because this species is capable of cyclopropanating a styrene derivative under mild conditions, its structural features are relevant for mechanistic discussions of π-acid catalysis in general.

Published online, DOI: 10.1002/anie.201402080 – Read now


 

Solid State Reactivity

Single Crystals Popping Under UV Light: A Photosalient Effect Triggered by a [2+2] Cycloaddition Reaction

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Raghavender Medishetty, Ahmad Husain, Zhaozhi Bai, Tomče Runčevski, Robert E. Dinnebier, Panče Naumov*, Jagadese J. Vittal*

Dancing crystals under UV light: The single crystals of three metal complexes burst under UV light like popcorn. The results demonstrate that solid-state [2+2] photocycloaddition reactions can be utilized for conversion of light into mechanical motion.

Published online, DOI: 10.1002/anie.201402040 – Read now


 

C–H Functionalization

Late-Stage Functionalization of Biologically Active Heterocycles Through Photoredox Catalysis

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Daniel A. DiRocco*, Kevin Dykstra, Shane Krska, Petr Vachal, Donald V. Conway, Matthew Tudge

Search and find: A method has been developed for the direct methyl-, ethyl-, and cyclopropylation of biologically active heterocycles using visible-light photoredox catalysis. High-throughput experimentation was used to discover the best catalyst. The simple protocol, mild reaction conditions, and unique tolerability make this method a valuable tool for drug discovery.

Published online, DOI: 10.1002/anie.201402023 – Read now


 

Photochemical Perfluoroalkylation

Metal-Free Photochemical Aromatic Perfluoroalkylation of α-Cyano Arylacetates

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Manuel Nappi, Giulia Bergonzini, Paolo Melchiorre*

Shining light: An operationally simple protocol for the direct aromatic perfluoroalkylation and trifluoromethylation of α-cyano arylacetates requires the irradiation by visible light at ambient temperature. This metal-free reaction is driven by the photochemical activity of electron donor–acceptor (EDA) complexes, formed in situ by the interaction of transiently generated enolates and perfluoroalkyl iodides.

Published online, DOI: 10.1002/anie.201402008 – Read now


 

Amide Synthesis

Amide Synthesis by Nucleophilic Attack of Vinyl Azides

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Feng-Lian Zhang, Yi-Feng Wang, Geoffroy Hervé Lonca, Xu Zhu, Shunsuke Chiba*

Nitrilium intermediate: A new method for amide synthesis employs vinyl azides as enamine-type nucleophiles towards carbon electrophiles in the presence of BF3·OEt2. After nucleophilic attack of the vinyl azide, a substituent of the resulting iminodiazonium ion intermediate A migrates to form nitrilium ion B, which is hydrolyzed to afford the corresponding amide.

Published online, DOI: 10.1002/anie.201400938 – Read now


 

H2S Splitting

An Integrated Photoelectrochemical–Chemical Loop for Solar-Driven Overall Splitting of Hydrogen Sulfide

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Xu Zong, Jingfeng Han, Brian Seger, Hongjun Chen, Gaoqing (Max) Lu, Can Li*, Lianzhou Wang*

Trash to Treasure: A photochemical–chemical loop for the overall H2S splitting was developed by integrating photoelectrochemical H2 production and H2S chemical absorption redox reactions with the link of a redox couple (Fe2+/Fe3+ or I/I3). Using functionalized silicon as photoelectrode, simultaneous extraction of H2 and elemental sulfur from H2S was successfully achieved (see picture).

Published online, DOI: 10.1002/anie.201400571 – Read now


 

Oligonucleotides

A New Pathway of DNA G-Quadruplex Formation

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Slavko Čeru, Primož Šket, Iztok Prislan, Jurij Lah*, Janez Plavec*

A new folding intermediate of Oxytricha nova telomeric Oxy-1.5 G-quadruplex was characterized in aqueous solution, where all guanine bases are involved in GG N1-carbonyl symmetric base pairs. G-rich DNA sequences can self-assemble into specific pre-organized DNA structures that are predisposed to fold into G-quadruplexes in the presence of cations such as potassium ions (see picture).

Published online, DOI: 10.1002/anie.201400531 – Read now


 

Block Copolymer Nanoparticles

A Facile Synthesis of Dynamic, Shape-Changing Polymer Particles

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Daniel Klinger, Cynthia Wang, Luke A. Connal, Debra J. Audus, Se Gyu Jang, Stephan Kraemer, Kato L. Killops, Glenn H. Fredrickson, Edward J. Kramer, Craig J. Hawker*

Let surfactants do the work: Controlling the shape and morphology of polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) particles through the use of tailored, mixed surfactant systems allows for the facile and selective preparation of ellipsoidal nanoparticles. Cross-linking of the axially stacked P2VP lamellae domains allows the pH responsiveness of the 2VP moieties to be exploited with generation of unique shape- and structure-responsive particles.

Published online, DOI: 10.1002/anie.201400183 – Read now


 

Catalytic Oxidation

A Trinuclear Pd3O2 Intermediate in Aerobic Oxidation Catalysis

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Andrew J. Ingram, Diego Solis-Ibarra, Richard N. Zare*, Robert M. Waymouth*

Catalytic ménage à trois: A catalytically active trinuclear Pd3O2 complex was identified during Pd-mediated aerobic oxidation of alcohols. Synthesis, structural characterization, and catalytic studies of the trinuclear compound show that it is a product of oxygen activation by reduced palladium species and is a competent intermediate in the catalytic aerobic oxidation of alcohols. These results illuminate a new pathway for O2 reduction by Pd complexes.

Published online, DOI: 10.1002/anie.201400134 – Read now


 

Reconfigurable Materials

Selective Janus Particle Assembly at Tipping Points of Thermally-Switched Wetting

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Changqian Yu, Jie Zhang, Steve Granick*

Thermal wetting reversibly joins patchy colloidal particles into clusters and crystals. This is demonstrated with Janus particles made of gold (A) half-coated silica (B) spheres immersed in a mixture of water and 2,6-lutidine such that the relative strength of gold–gold bonding through hydrophobic interaction and silica–silica bonding through wetting-induced attraction is reversibly switched by temperature changes of only 1–2 °C.

Published online, DOI: 10.1002/anie.201310465 – Read now


 

Antimicrobial Polymers

Antimicrobial Poly(2-methyloxazoline)s with Bioswitchable Activity through Satellite Group Modification

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Christian Krumm, Simon Harmuth, Montasser Hijazi, Britta Neugebauer, Anne-Larissa Kampmann, Helma Geltenpoth, Albert Sickmann, Joerg C. Tiller*

Biocides are widely used for preventing the spread of microbial infections and the fouling of materials. Since their application can build up microbial resistance and cause unpredictable long-term environmental problems, new biocidal agents are required. In a novel approach an antimicrobial polymer is deactivated by hydrolysis of an ester group through the action of a lipase. The crucial feature is the mutual interaction of the two endgroups of the polymer.

Published online, DOI: 10.1002/anie.201311150 – Read now No. 15/2014.


 

Chemical Protein Synthesis

Total Chemical Synthesis of the Enzyme Sortase AΔN59 with Full Catalytic Activity

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Fang-Kun Deng, Liang Zhang, Ya-Ting Wang, Olaf Schneewind, Stephen B. H. Kent*

Just like the original: A fully convergent total synthesis of the enzyme sortase A from four unprotected peptide segments was established by using modern chemical ligation methods. The synthetic protein was of high purity, had correct mass, and had showed enzymatic activity in a typical transpeptidation assay.

Published online, DOI: 10.1002/anie.201310900 – Read now


 

Hole Transport

A Simple 3,4-Ethylenedioxythiophene Based Hole-Transporting Material for Perovskite Solar Cells

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Hairong Li, Kunwu Fu, Anders Hagfeldt, Michael Grätzel, Subodh G. Mhaisalkar*, Andrew C. Grimsdale*

Heterocycle power! A power-conversion efficiency of 13.8 % under AM 1.5G illumination was achieved in a perovskite-based solar cell with a new hole-transporting material based on 3,4-ethylenedioxythiophene (H101). This is the first heterocycle-containing material with >10 % efficiency in such devices, and has great potential to replace the more expensive spiro-OMeTAD, given its much simpler and less expensive synthesis.

Published online, DOI: 10.1002/anie.201310877 – Read now


 

Bifunctional Nanopeapods

Peapod-Type Nanocomposites through the In Situ Growth of Gold Nanoparticles within Preformed Hexaniobate Nanoscrolls

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Shiva Adireddy, Cecilia E. Carbo, Taha Rostamzadeh, Jose M. Vargas, Leonard Spinu, John B. Wiley*

Like peas in a pod: A facile in situ method for Au nanoparticle (NP) growth in nanoscrolls is applied to the formation of plasmonic Au@hexaniobate and bifunctional plasmonic-magnetic Au-Fe3O4@hexaniobate nanopeapods (NPPs). Using a solvothermal treatment, rigid multiwalled hexaniobate nanoscrolls and partially filled Fe3O4@hexaniobate NPPs were formed and used as templates for the Au NPs.

Published online, DOI: 10.1002/anie.201310834 – Read now


 

Biomineralization

Functionalizing Single Crystals: Incorporation of Nanoparticles Inside Gel-Grown Calcite Crystals

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Yujing Liu, Wentao Yuan, Ye Shi, Xiaoqiang Chen, Yong Wang, Hongzheng Chen, Hanying Li*

Functionalization of crystals: Biogenic single crystals incorporate biomacromolecules and form single-crystal composites. The abnormal composite structure led to the idea to obtain synthetic crystals with nonintrinsic properties by modifing their internal structure. Intrinsically colorless and diamagnetic calcite single crystals are turned into colored and paramagnetic solids through incorporation of gold and ferroferric oxide nanoparticles.

Published online, DOI: 10.1002/anie.201310712 – Read now


 

Photopatterning

Direct UV-Induced Functionalization of Surface Hydroxy Groups by Thiol–Ol Chemistry

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Linxian Li, Junsheng Li, Xin Du, Alexander Welle, Michael Grunze, Oliver Trapp, Pavel A. Levkin*

When thiols meet alcohols. A method based on thiol–alcohol chemistry is used for the direct photochemical modification and patterning of hydroxy-functionalized surfaces with different thiol-containing functional molecules (see picture).

Published online, DOI: 10.1002/anie.201310692 – Read now No. 15/2014.


 

Heterocycle Synthesis

Rhodium Enalcarbenoids: Direct Synthesis of Indoles by Rhodium(II)-Catalyzed [4+2] Benzannulation of Pyrroles

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Sudam Ganpat Dawande, Vinaykumar Kanchupalli, Jagadeesh Kalepu, Haribabu Chennamsetti, Bapurao Sudam Lad, Sreenivas Katukojvala*

Fat cat: A new class of enaldiazo compounds resulted in the first transition-metal-catalyzed [4+2] benzannulation of pyrroles to deliver indoles. The benzannulation is proposed to involve an unprecedented diacceptor rhodium enalcarbenoid. The reaction was used in the highly efficient synthesis of the natural product leiocarpone and a potent adipocyte fatty-acid binding protein inhibitor.

Published online, DOI: 10.1002/anie.201400161 – Read now


 

Redox Catalysis

A Brønsted Acid Catalyzed Redox Arylation

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Bo Peng, Xueliang Huang, Lan-Gui Xie, Nuno Maulide*

Playing a neutral game: A Brønsted acid catalyzed redox-neutral arylation of ynamides with aryl sulfoxides is described. A broad range of ynamides were converted into the corresponding α-arylated oxazolidinones in good to excellent yields under mild conditions and in an atom-economic fashion. Tf=trifluoromethylsulfonyl.

Published online, DOI: 10.1002/anie.201310865 – Read now


 

Prussian Blue Nanoparticles

Nanosized Heterostructures of Au@Prussian Blue Analogues: Towards Multifunctionality at the Nanoscale

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Guillaume Maurin-Pasturel, Jérôme Long, Yannick Guari*, Franck Godiard, Marc-Georg Willinger, Christian Guerin, Joulia Larionova

Prussian gold: A method for the synthesis of single- and double-layer core–shell heterostructures that are based on a well-defined gold core and shells of Prussian blue analogues has been developed. These materials feature magneto-optical properties and may be considered as multifunctional nanoobjects.

Published online, DOI: 10.1002/anie.201310443 – Read now No. 15/2014.


 

Sodium Batteries

All Organic Sodium-Ion Batteries with Na4C8H2O6

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Shiwen Wang, Lijiang Wang, Zhiqiang Zhu, Zhe Hu, Qing Zhao, Jun Chen*

More salt, please: Organic tetrasodium salts of 2,5-dihydroxyterephthalic acid (Na4DHTPA) can reversibly react with two Na+ ions at 1.6–2.8 V and 0.1–1.8 V, respectively. This material can be used to build a symmetrical all-organic rocking-chair cell with an average voltage of 1.8 V and an energy density of about 65 Wh kg−1.

Published online, DOI: 10.1002/anie.201400032 – Read now


 

Amino Acid Chemistry

The Formation and Self-Assembly of Long Prebiotic Oligomers Produced by the Condensation of Unactivated Amino Acids on Oxide Surfaces

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Gianmario Martra*, Chiara Deiana, Yuriy Sakhno, Ilvis Barberis, Marco Fabbiani, Marco Pazzi, Marco Vincenti

Prebiotic peptides: The catalytic formation from unactivated glycine vapor of poly-Gly up to 16 units long on a surface of SiO2 or TiO2 and the subsequent self-assembly of the polypeptides into closely packed aggregates upon contact with water has been observed. Both aspects can provide useful insights into the general problem of the surface reactivity of amino acids, and in particular, the prebiotic formation of biopolymers and their subsequent self-organization.

Published online, DOI: 10.1002/anie.201311089 – Read now


 

Gold Catalysis

Cyclization of Gold Acetylides: Synthesis of Vinyl Sulfonates via Gold Vinylidene Complexes

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Janina Bucher, Thomas Wurm, Kumara Swamy Nalivela, Matthias Rudolph, Frank Rominger, A. Stephen K. Hashmi*

Gold vinylidene intermediates are generated by the cyclization of gold acetylides that carry a sulfonate leaving group. This result demonstrates for the first time that the formation of these species is not restricted to a dual activation mode. The cyclization products obtained herein contain a vinyl sulfonate moiety, which makes them useful building blocks for cross-coupling reactions.

Published online, DOI: 10.1002/anie.201310280 – Read now No. 15/2014.


 

Protein Aggregation

Interaction with the Surrounding Water Plays a Key Role in Determining the Aggregation Propensity of Proteins

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Song-Ho Chong, Sihyun Ham*

Water, water, everywhere: Understanding the causes of protein aggregation is a central issue for understanding and preventing protein-aggregation diseases. Most studies to date have focused on the protein sequences without fully addressing the role of the surrounding water molecules. In fact, the interaction of a protein with the water surrounding it was found to play a pivotal role in determining its hydrophobicity and thus its aggregation propensity.

Published online, DOI: 10.1002/anie.201309317 – Read now No. 15/2014.


 

Electrocatalysts

Carbon Nanotubes/Heteroatom-Doped Carbon Core–Sheath Nanostructures as Highly Active, Metal-Free Oxygen Reduction Electrocatalysts for Alkaline Fuel Cells

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Young Jin Sa, Chiyoung Park, Hu Young Jeong, Seok-Hee Park, Zonghoon Lee, Kyoung Taek Kim, Gu-Gon Park, Sang Hoon Joo*

A facile, scalable route for the synthesis of new nanocomposites that are based on carbon nanotubes/heteroatom-doped carbon (CNT/HDC) core–sheath nanostructures has been developed. The CNT/HDC nanostructures exhibit excellent electrocatalytic activity, kinetics, and durability for the oxygen reduction reaction, and they also performed well as the cathode catalysts in alkaline fuel cells.

Published online, DOI: 10.1002/anie.201307203 – Read now


 

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