Chemistry - A European Journal

Cover image for Vol. 20 Issue 2

January 7, 2014

Volume 20, Issue 2

Pages 337–608

  1. Cover Pictures

    1. Top of page
    2. Cover Pictures
    3. Cover Profile
    4. Graphical Abstract
    5. News
    6. Concept
    7. Communications
    8. Full Papers
    1. You have free access to this content
      Cover Picture: Hydrogen-Bonding in Aminocatalysis: From Proline and Beyond (Chem. Eur. J. 2/2014) (page 337)

      Dr. Łukasz Albrecht, Dr. Hao Jiang and Prof. Dr. Karl Anker Jørgensen

      Article first published online: 3 JAN 2014 | DOI: 10.1002/chem.201490004

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      “The magic touch!” The sphere in the middle of the picture symbolizes the hydrogen atom, the element that plays a central role in hydrogen-bonding aminocatalysis. Two hands are very significant and refer to the topic of chirality, which lies at the heart of asymmetric synthesis. The lightning formed by the hands touching the sphere manifests hydrogen-bonding, thus enabling efficient chirality transfer, as found in many reactions described in the Concept article by K. A. Jørgensen et al. on page 340 ff.

    2. You have free access to this content
      Inside Cover: Ionic Liquids Supported on Metal-Organic Frameworks: Remarkable Adsorbents for Adsorptive Desulfurization (Chem. Eur. J. 2/2014) (page 338)

      Dr. Nazmul Abedin Khan, Zubair Hasan and Prof. Dr. Sung Hwa Jhung

      Article first published online: 3 JAN 2014 | DOI: 10.1002/chem.201490000

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      Acidic ionic lquids supported on  metal–organic frameworks (MOFs) have been shown to have application in adsorptive desulfurization. A remarkable improvement in the adsorption capacity (ca. 71 %) was observed in the IL-supported MIL-101 MOF compared to the virgin MIL-101 MOF. For more details see the Communication by S. H. Jhung et al. on page 376 ff.

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      Back Cover: Quantum Mechanics/Molecular Mechanics Study on the Oxygen Binding and Substrate Hydroxylation Step in AlkB Repair Enzymes (Chem. Eur. J. 2/2014) (page 612)

      Matthew G. Quesne, Dr. Reza Latifi, Luis E. Gonzalez-Ovalle, Dr. Devesh Kumar and Dr. Sam P. de Visser

      Article first published online: 3 JAN 2014 | DOI: 10.1002/chem.201490003

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      DNA repair enzymes  from a fungus were investigated using quantum mechanics/molecular mechanics calculations. These studies have elucidated a novel mechanism that is initiated with an iron(IV)–oxo isomerisation gated by an arginine latch. Further details can be found in the Full Paper by S. de Visser and co-workers on page 435 ff.

  2. Cover Profile

    1. Top of page
    2. Cover Pictures
    3. Cover Profile
    4. Graphical Abstract
    5. News
    6. Concept
    7. Communications
    8. Full Papers
    1. You have free access to this content
      Hydrogen-Bonding in Aminocatalysis: From Proline and Beyond (page 340)

      Dr. Łukasz Albrecht, Dr. Hao Jiang and Prof. Dr. Karl Anker Jørgensen

      Article first published online: 3 JAN 2014 | DOI: 10.1002/chem.201304668

      The number of proline-related hydrogen-bonding aminocatalysts synthesized in the last few years is simply astonishing. This field of research is growing and developing at a fast pace.” Read more about the story behind the cover in the Cover Profile and about the research itself on page 340 ff.

  3. Graphical Abstract

    1. Top of page
    2. Cover Pictures
    3. Cover Profile
    4. Graphical Abstract
    5. News
    6. Concept
    7. Communications
    8. Full Papers
    1. Graphical Abstract: Chem. Eur. J. 2/2014 (pages 341–350)

      Article first published online: 3 JAN 2014 | DOI: 10.1002/chem.201490001

  4. News

    1. Top of page
    2. Cover Pictures
    3. Cover Profile
    4. Graphical Abstract
    5. News
    6. Concept
    7. Communications
    8. Full Papers
  5. Concept

    1. Top of page
    2. Cover Pictures
    3. Cover Profile
    4. Graphical Abstract
    5. News
    6. Concept
    7. Communications
    8. Full Papers
    1. Aminocatalysis

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      Hydrogen-Bonding in Aminocatalysis: From Proline and Beyond (pages 358–368)

      Dr. Łukasz Albrecht, Dr. Hao Jiang and Prof. Dr. Karl Anker Jørgensen

      Article first published online: 5 DEC 2013 | DOI: 10.1002/chem.201303982

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      It's all in the H-bond! This Concept article summarizes recent progress in the field of hydrogen-bonding aminocatalysis using proline-derived systems. Aminocatalysts available in the literature are categorized by the incorporated hydrogen-bonding scaffold and its mode of recognition. Both mono- and double-hydrogen-bonding motifs are discussed and the examples of their application in asymmetric synthesis are given (see scheme).

  6. Communications

    1. Top of page
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    3. Cover Profile
    4. Graphical Abstract
    5. News
    6. Concept
    7. Communications
    8. Full Papers
    1. Isotopes

      Fast and Efficient 18F-Labeling by [18F]Fluorophenylazocarboxylic Esters (pages 370–375)

      Stefanie K. Fehler, Dr. Simone Maschauer, Dr. Sarah B. Höfling, Amelie L. Bartuschat, Dr. Nuska Tschammer, Dr. Harald Hübner, Prof. Dr. Peter Gmeiner, Prof. Dr. Olaf Prante and Prof. Dr. Markus R. Heinrich

      Article first published online: 11 DEC 2013 | DOI: 10.1002/chem.201303409

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      Aromatic substitution: Introduction of [18F]fluoride ion into the aromatic core of phenylazocarboxylic esters was achieved in only 30 seconds, and with radiochemical yields up to 95 % (85(±10) %). For labeling purposes, the resulting 18F-substituted azoester can be further converted in radical-arylation reactions to give biaryls, or in substitutions at its carbonyl unit to produce azocarboxamides (see scheme).

    2. Metal–Organic Frameworks

      Ionic Liquids Supported on Metal-Organic Frameworks: Remarkable Adsorbents for Adsorptive Desulfurization (pages 376–380)

      Dr. Nazmul Abedin Khan, Zubair Hasan and Prof. Dr. Sung Hwa Jhung

      Article first published online: 20 DEC 2013 | DOI: 10.1002/chem.201304291

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      Getting rid of sulfur: Adsorptive desulfurization of model fuels has been investigated with metal–organic frameworks (MOFs) after loading with ionic liquid (IL). Performance of adsorptive desulfurization was enhanced by 71 % upon loading of ionic liquids (see figure).

    3. Sensors

      Cyclization-Induced Turn-On Fluorescence System Applicable to Dicarboxylate Sensing (pages 381–384)

      Dr. Takao Noguchi, Dr. Bappaditya Roy, Dr. Daisuke Yoshihara, Dr. Youichi Tsuchiya, Dr. Tatsuhiro Yamamoto and Prof. Seiji Shinkai

      Article first published online: 16 DEC 2013 | DOI: 10.1002/chem.201304031

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      Not aggregation, but cyclization: A novel tetraphenylethene-based fluorescence (FL) chemosensor exhibits nonlinear turn-on FL switching through cooperative binding of L-tartarate. The convergent binding to form cyclic substructures is responsible for the FL increase (see graphic). This binding scheme achieves selective detection of dicarboxylates over monocarboxylates, thus being potentially applicable to preliminary screening for metabolic disorders.

    4. Catalysis

      Rhodium-Catalyzed Annulative Coupling of 3-Phenylthiophenes with Alkynes Involving Double C-H Bond Cleavages (pages 385–389)

      Tomonori Iitsuka, Dr. Koji Hirano, Prof. Dr. Tetsuya Satoh and Prof. Dr. Masahiro Miura

      Article first published online: 29 NOV 2013 | DOI: 10.1002/chem.201303847

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      C[BOND]H activation: Double C[BOND]H bond activation took place efficiently upon treatment of 3-phenylthiophenes with alkynes in the presence of a rhodium catalyst and a copper salt oxidant to form the corresponding naphthothiophene derivatives. Dehydrogenative coupling with alkenes was also found to occur on the phenyl moiety rather than the thiophene ring (see scheme).

    5. Polycyclic Aromatics

      Exo-Dig Radical Cascades of Skipped Enediynes: Building a Naphthalene Moiety within a Polycyclic Framework (pages 390–393)

      Dr. Kamalkishore Pati, Audrey M. Hughes, Hoa Phan and Prof. Igor V. Alabugin

      Article first published online: 22 NOV 2013 | DOI: 10.1002/chem.201304092

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      Right round: This report describes a selective sequence of 5-exo-dig and 6-exo-dig cyclizations followed by attack at a pendant aromatic moiety and rearomatization (see scheme; AlBN=2,2′-azobisisobutyronitrile). The overall transformation is a new approach for building a naphthalene moiety within a polycyclic framework. Furthermore, the high efficiency for the key 6-exo-step of the cascade paves the way for the preparation of defect-free graphene nanoribbons.

    6. Antibacterial Nanomaterials

      Reduced Graphene Oxide Functionalized with a Luminescent Rare-Earth Complex for the Tracking and Photothermal Killing of Drug-Resistant Bacteria (pages 394–398)

      Xinjian Yang, Zhenhua Li, Enguo Ju, Prof. Dr. Jinsong Ren and Prof. Dr. Xiaogang Qu

      Article first published online: 10 DEC 2013 | DOI: 10.1002/chem.201303964

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      Track down and kill: A near-infrared (NIR) light-responsive antibacterial platform based on multifunctional reduced graphene oxide has been constructed. By introducing a luminescent Eu3+ complex and vancomocin, it could specifically recognize and light up bacteria. Upon illumination with NIR light, this nanoarchitecture generates much heat locally, resulting in the death of drug-resistant bacteria.

    7. Organic Synthesis

      Base-Catalyzed Tandem Michael/Dehydro-Diels–Alder Reaction of α,α-Dicyanoolefins with Electron-Deficient 1,3-Conjugated Enynes: A Facile Entry to Angularly Fused Polycycles (pages 399–404)

      Mingrui Zhang and Prof. Junliang Zhang

      Article first published online: 2 DEC 2013 | DOI: 10.1002/chem.201302960

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      Go domino! A tandem Michael addition/dehydro-Diels–Alder reaction of readily available electron-deficient 1,3-conjugated enynes and α,α-dicyanoolefins under mild conditions was developed that provides facile access to angularly fused polycycles with multiple consecutive stereogenic centers in one step (see scheme; DBU=1,8-diazabicyclo[5.4.0]undec-7-ene; DCE=1,2-dicholoethane).

    8. Facile Access to cis-2,6-Disubstituted Tetrahydropyrans by Palladium-Catalyzed Decarboxylative Allylation: Total Syntheses of (±)-Centrolobine and (+)-Decytospolides A and B (pages 405–409)

      Jing Zeng, Yu Jia Tan, Dr. Jimei Ma, Min Li Leow, Davin Tirtorahardjo and Prof. Dr. Xue-Wei Liu

      Article first published online: 27 NOV 2013 | DOI: 10.1002/chem.201303328

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      Pump up the stereo! Stereospecific access to cis-2,6-disubstituted tetrahydropyrans was achieved with high efficiency by a palladium-catalyzed decarboxylative allylation. With this strategy, total syntheses of (±)-centrolobine and (+)-decytospolides A and B have been accomplished in concise steps (see scheme; DtBPF=1,1′-bis(di-tert-butylphosphino)ferrocene).

    9. α,β-Unsaturated Acyl Cyanides as New Bis-Electrophiles for Enantioselective Organocatalyzed Formal [3+3]Spiroannulation (pages 410–415)

      Sébastien Goudedranche, Dr. Xavier Bugaut, Prof. Thierry Constantieux, Dr. Damien Bonne and Prof. Jean Rodriguez

      Article first published online: 4 DEC 2013 | DOI: 10.1002/chem.201303613

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      Go organic! α,β-Unsaturated acyl cyanides are key bis-electrophile substrates for successful domino enantioselective organocatalyzed Michael-intramolecular acylation domino sequences (see scheme). This new reactivity has been applied to the synthesis of enantioenriched the azaspiro[4,5]decanone ring systems by a formal [3+3]spiroannulation.

    10. C[BOND]H Activation

      Rhodium-Catalyzed Directed Sulfenylation of Arene C[BOND]H Bonds (pages 416–420)

      Dr. Yaxi Yang, Dr. Wei Hou, Lihuai Qin, Dr. Juanjuan Du, Huijin Feng, Dr. Bing Zhou and Dr. Yuanchao Li

      Article first published online: 28 NOV 2013 | DOI: 10.1002/chem.201303730

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      Mono- or dithiolation: The first rhodium-catalyzed intermolecular direct C[BOND]H thiolation of arenes with aryl and alkyl disulfides is developed to provide a convenient route to aryl thioethers. This strategy is compatible with different directing groups and exhibits excellent functional group tolerance. Significantly, mono- or dithiolation can be selectively achieved, thus providing a straightforward way for selective preparation of aryl thioethers and dithioethers (see scheme).

    11. Hollow Structures

      Synthesis of Porous, Hollow Metal MCO3 (M=Mn, Co, Ca) Microstructures and Adsorption Properties Thereof (pages 421–425)

      Ren Cai, Prof. Yaping Du, Shengjie Peng, Hengchang Bi, Wenyu Zhang, Dan Yang, Jing Chen, Prof. Tuti Mariana Lim, Prof. Hua Zhang, Prof. Y. Charles Cao and Prof. Qingyu Yan

      Article first published online: 29 NOV 2013 | DOI: 10.1002/chem.201302052

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      Porous, hollow metal carbonate microstructures show many unique properties, and are attractive for various applications. A general synthetic strategy for hollow metal carbonate structures is reported, including porous MnCO3 hollow cubes, porous CoCO3 hollow rhombuses and porous CaCO3 hollow capsules. The method could be broadly applicable to other porous hollow structures and shows great promise for various applications (see figure).

  7. Full Papers

    1. Top of page
    2. Cover Pictures
    3. Cover Profile
    4. Graphical Abstract
    5. News
    6. Concept
    7. Communications
    8. Full Papers
    1. Metal–Organic Frameworks

      Enhancing CO2 Separation Ability of a Metal–Organic Framework by Post-Synthetic Ligand Exchange with Flexible Aliphatic Carboxylates (pages 426–434)

      Dae Ho Hong and Prof. Myunghyun Paik Suh

      Article first published online: 20 DEC 2013 | DOI: 10.1002/chem.201303801

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      CO2 removal: Various alkanedioate pendants have been incorporated into the framework of UiO-66 by post-synthetic ligand exchange (see graphic). An adipic acid pendant showed the most marked enhancing effects on both the capacity and the selectivity of CO2 adsorption at 298 and 323 K. Such a flexible carboxylic acid pendant of appropriate length provides an increased enthalpy loss and a decreased entropy loss upon CO2 adsorption.

    2. DNA Damage

      You have full text access to this OnlineOpen article
      Quantum Mechanics/Molecular Mechanics Study on the Oxygen Binding and Substrate Hydroxylation Step in AlkB Repair Enzymes (pages 435–446)

      Matthew G. Quesne, Dr. Reza Latifi, Luis E. Gonzalez-Ovalle, Dr. Devesh Kumar and Dr. Sam P. de Visser

      Article first published online: 11 DEC 2013 | DOI: 10.1002/chem.201303282

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      Right of passage: A combination of density functional theory and quantum mechanics/molecular mechanics studies is presented on the oxygen activation by AlkB repair enzymes. These studies identify the substrate and oxygen binding sites and the origin of their structural separation. It is also shown that the Arg210 residue in the active site acts as a latch that only allows the iron(IV)–oxo to pass and react with substrate (see figure).

    3. Photochemistry

      Synthesis and Photophysics of a New Family of Fluorescent 9-Alkyl-Substituted Xanthenones (pages 447–455)

      Ángela Martínez-Peragón, Dr. Delia Miguel, Rocío Jurado, Dr. José Justicia, Prof. José M. Álvarez-Pez, Dr. Juan M. Cuerva and Dr. Luis Crovetto

      Article first published online: 28 NOV 2013 | DOI: 10.1002/chem.201303113

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      Finely tuned fluorescence: 9-Alkyl xanthenones with different aliphatic pendant groups have been easily prepared by means of nucleophilic addition of the corresponding Grignard derivative to a tert-butyldimethylsilyl ether (TBDMS)-protected 3,6-dihydroxy-xanthenone. The photophysical behavior of the new dyes has been explored by using absorption-, steady-state, and time-resolved fluorescence measurements (see figure).

    4. Peptides

      A Mechanistic Study of the Spontaneous Hydrolysis of Glycylserine as the Simplest Model for Protein Self-Cleavage (pages 456–466)

      Dr. Tzvetan T. Mihaylov, Prof. Dr. Tatjana N. Parac-Vogt and Prof. Dr. Kristine Pierloot

      Article first published online: 5 DEC 2013 | DOI: 10.1002/chem.201303564

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      Protein self-cleavage at serine residues: To examine the inherent hydrolytic ability of serine-containing peptides, a detailed theoretical and experimental study of the spontaneous hydrolysis of glycylserine has been performed. Based on the resulting models, possible mechanistic scenarios for both uncatalyzed and self-catalyzed peptide-bond cleavage in proteins have been proposed (see scheme).

    5. Nanostructures

      In Situ Growth of Hierarchical SnO2 Nanosheet Arrays on 3D Macroporous Substrates as High-Performance Electrodes (pages 467–473)

      Dr. Xinyu Zhao, Dr. Bing Liu, Prof. Changwen Hu and Prof. Minhua Cao

      Article first published online: 4 DEC 2013 | DOI: 10.1002/chem.201303548

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      The Li-ion king: Finding out how to overcome the self-aggregation of nanostructured electrode materials is a very important issue in lithium-ion battery technology. By following an in situ construction strategy, hierarchical SnO2 nanosheet architectures have been grown on a 3D macroporous nickel foam substrate, and have then been evaluated as electrodes for high-performance lithium-ion batteries (see figure).

    6. Solar Cells

      Well-Dispersed CoS Nanoparticles on a Functionalized Graphene Nanosheet Surface: A Counter Electrode of Dye-Sensitized Solar Cells (pages 474–482)

      Dr. Xiaohuan Miao, Prof. Kai Pan, Prof. Guofeng Wang, Dr. Yongping Liao, Dr. Lei Wang, Dr. Wei Zhou, Dr. Baojiang Jiang, Prof. Qingjiang Pan and Prof. Guohui Tian

      Article first published online: 4 DEC 2013 | DOI: 10.1002/chem.201303558

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      Dye-sensitized solar cells (DSSCs) have been fabricated with uniform CoS nanoparticles on the surface of functionalized graphene nanosheets (FGNS-CoS). The resulting composite counter electrode exhibits a higher photoelectrical conversion efficiency than the DSSCs based on the non-uniform CoS nanoparticles on FGNS and the naked CoS nanoparticles (see figure). The uniform FGNS-CoS composite counter electrode has the best catalytic activity and the fastest electron-transport.

    7. Chromophores

      Functional carbo-Butadienes: Nonaromatic Conjugation Effects through a 14-Carbon, 24-π-Electron Backbone (pages 483–492)

      Dr. Arnaud Rives, Dr. Valérie Maraval, Dr. Nathalie Saffon-Merceron and Prof. Remi Chauvin

      Article first published online: 5 DEC 2013 | DOI: 10.1002/chem.201303169

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      The more the merrier: A systematic study of carbo-butadiene motifs not embedded in an aromatic ring is described (see scheme; E: electrophilic group). All of the acyclic dibutatrienylacetylene products adopt a planar transtransoidtrans configuration. The results provide an experimental basis for the design of π-extended organic molecules with promising optical or (opto)electronic properties.

    8. Metallacrowns

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      Crown-Ether-Like Structures Derived from a Ti8O8(Carboxylate)16 Metallacycle (pages 493–498)

      Christine Artner, Matthias Czakler and Prof. Dr. Ulrich Schubert

      Article first published online: 4 DEC 2013 | DOI: 10.1002/chem.201302892

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      Crowning glory: The reaction of titanium alkoxides with strontium or lead acetate and methacrylic acid results in [TiO(OOCR)2]8 metallacrowns with incorporated Sr or Pb ions (see figure). In addition to the crown-ether-like coordination of the ring oxygen atoms, bridging carboxylate ligands support the coordination of the Sr or Pb ions.

    9. Drug Delivery

      Self-Assembly of Hierarchical Nanostructures from Dopamine and Polyoxometalate for Oral Drug Delivery (pages 499–504)

      Hong Li, Dr. Yi Jia, Dr. Anhe Wang, Dr. Wei Cui, Hongchao Ma, Xiyun Feng and Prof. Dr. Junbai Li

      Article first published online: 4 DEC 2013 | DOI: 10.1002/chem.201302660

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      3D hierarchical nanostructures: Hierarchical nanostructures have been prepared through the self-assembly of dopamine and phosphotungstic acid. The size and morphology of the organic–inorganic hybrid materials can be modulated by varying the synthetic parameters. Moreover, the hierarchical nanostructures showed intriguing pH-dependent release of an anti-cancer drug (see figure), making them promising for oral drug delivery.

    10. Layered Compounds

      Synthesis of Triple-Layered Ag@Co@Ni Core–Shell Nanoparticles for the Catalytic Dehydrogenation of Ammonia Borane (pages 505–509)

      Dr. Fangyuan Qiu, Dr. Guang Liu, Dr. Li Li, Dr. Ying Wang, Changchang Xu, Dr. Cuihua An, Chengcheng Chen, Dr. Yanan Xu, Yanan Huang, Prof. Yijing Wang, Prof. Lifang Jiao and Prof. Huatang Yuan

      Article first published online: 2 DEC 2013 | DOI: 10.1002/chem.201302943

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      Split personality: Triple-layered Ag@Co@Ni core–shell nanoparticles containing a silver core, a cobalt inner shell, and a nickel outer shell were formed by an in situ chemical reduction method (see figure). Ag0.04@Co0.48@Ni0.48 showed the most distinct core–shell structure. This catalyst, with non-noble double shells, has excellent catalytic activity for the hydrolysis of NH3BH3.

    11. Friedel–Crafts Reaction

      Iron-Catalyzed Friedel–Crafts Benzylation with Benzyl TMS Ethers at Room Temperature (pages 510–516)

      Dr. Yoshinari Sawama, Yuko Shishido, Takahiro Kawajiri, Ryota Goto, Dr. Yasunari Monguchi and Prof. Dr. Hironao Sajiki

      Article first published online: 2 DEC 2013 | DOI: 10.1002/chem.201302862

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      Get crafty! Mono- or bis-benzylated arenes were obtained in high yield with good regioselectivity by iron-catalyzed Friedel–Crafts reactions between benzyl TMS ethers and arenes (see scheme; TMS=trimethylsilyl). The outcome of the reactions was controlled by reagent stoichiometry.

    12. Graphene

      Manganese Oxide/Graphene Aerogel Composites as an Outstanding Supercapacitor Electrode Material (pages 517–523)

      Chun-Chieh Wang, Hsuan-Ching Chen and Prof. Dr. Shih-Yuan Lu

      Article first published online: 10 DEC 2013 | DOI: 10.1002/chem.201303483

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      Graphene aerogel: High specific surface areas, large pore volumes, and high electric conductivities of graphene aerogels (GA) enable high MnO2-loading ratios with an excellent high rate capability of MnO2/GA, making them potential outstanding supercapacitor electrode materials (see figure).

    13. Analytical Chemistry

      Planar and Nonplanar Free-Base Tetraarylporphyrins: β-Pyrrole Substituents and Geometric Effects on Electrochemistry, Spectroelectrochemistry, and Protonation/Deprotonation Reactions in Nonaqueous Media (pages 524–532)

      Yuanyuan Fang, Prof. P. Bhyrappa, Prof. Zhongping Ou and Prof. Karl M. Kadish

      Article first published online: 2 DEC 2013 | DOI: 10.1002/chem.201303141

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      A series of planar and nonplanar free-base porphyrins (P) are characterized by UV/Vis spectroscopy, electrochemistry, and spectroelectrochemistry in CH2Cl2 containing added acid or base. The effects of macrocycle planarity, substituent effects, solution basicity on spectroscopic, and redox properties of the compounds are discussed.

    14. Gels

      A New Class of Dendritic Metallogels with Multiple Stimuli-Responsiveness and as Templates for the In Situ Synthesis of Silver Nanoparticles (pages 533–541)

      Zhi-Xiong Liu, Dr. Yu Feng, Dr. Zhi-Yong Zhao, Zhi-Chao Yan, Yan-Mei He, Xu-Jun Luo, Prof. Dr. Chen-Yang Liu and Prof. Dr. Qing-Hua Fan

      Article first published online: 11 DEC 2013 | DOI: 10.1002/chem.201302780

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      Intelligent gels: A new class of dendritic organometallic gels was fabricated from pyridine-functionalized poly(aryl ether) dendritic complexes through hierarchical self-assembly. The metallogels could respond intelligently to multiple external stimuli including temperature, chemicals, and shear stress, leading to gel–sol phase transitions. In addition, the dendritic metallogels were successfully used as templates for the in situ formation and stabilization of silver nanoparticles without the use of any chemical reducing/stabilizing agents.

    15. Energetic Materials

      1,2,3-Triazolo[4,5,-e]furazano[3,4,-b]pyrazine 6-Oxide—A Fused Heterocycle with a Roving Hydrogen Forms a New Class of Insensitive Energetic Materials (pages 542–548)

      Dr. Venugopal Thottempudi, Dr. Ping Yin, Dr. Jiaheng Zhang, Dr. Damon A. Parrish and Prof. Dr. Jean'ne M. Shreeve

      Article first published online: 28 NOV 2013 | DOI: 10.1002/chem.201303469

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      High energy: Single-crystal X-ray studies show that in 1,2,3-triazolo[4,5-e]furazano[3,4-b]pyrazine 6-oxide, the hydrogen atom is bonded to the pyrazine nitrogen and not the nitrogen of the triazole ring; however, the proton transfer to cations is from the more reactive triazole nitrogen, forming a new class of insensitive energetic materials.

    16. Green Chemistry

      From Waste Biomass to Solid Support: Lignosulfonate as a Cost-Effective and Renewable Supporting Material for Catalysis (pages 549–558)

      Shaohuan Sun, Dr. Rongxian Bai and Prof. Dr. Yanlong Gu

      Article first published online: 4 DEC 2013 | DOI: 10.1002/chem.201303364

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      Trash, but not as we know it! Lignosulfonate (LS) is a waste biomass generated as a byproduct of a cooking process in sulfite pulping in the manufacture of paper. LS was used as an anionic supporting material for immobilizing cationic species, which can then be used as a heterogeneous catalyst in some organic transformations (see scheme).

    17. Organocatalysis

      2,2,2-Trifluoroacetophenone as an Organocatalyst for the Oxidation of Tertiary Amines and Azines to N-Oxides (pages 559–563)

      Dimitris Limnios and Dr. Christoforos G. Kokotos

      Article first published online: 2 DEC 2013 | DOI: 10.1002/chem.201303360

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      Fluorine power: The cheap, fast, environmentally friendly oxidation of tertiary amines and azines to the corresponding N-oxides is reported by using polyfluoroalkyl ketones as efficient organocatalysts. Aliphatic tertiary amines and azines are oxidized chemoselectively in high to quantitative yields utilizing 10 mol % catalyst loading and H2O2 as the oxidant (see scheme).

    18. Electrochemistry

      Nitrogen-Doped Porous Graphitic Carbon as an Excellent Electrode Material for Advanced Supercapacitors (pages 564–574)

      Dr. Li Sun, Dr. Chungui Tian, Yu Fu, Dr. Ying Yang, Dr. Jie Yin, Dr. Lei Wang and Prof. Honggang Fu

      Article first published online: 4 DEC 2013 | DOI: 10.1002/chem.201303345

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      Energy storage made easy: Nitrogen-doped porous graphitic carbon (NPGC) materials with large surface areas (1027 m2 g−1) and high nitrogen levels (7.72 wt %) were produced by a robust coordination–pyrolysis process (see figure). The prepared NPGC materials exhibit excellent capacitive behavior, superior cycling stability, and high energy and power densities as electrode material for advanced supercapacitors.

    19. Supramolecular Polymers

      Self-Assembly of Three-Dimensional Supramolecular Polymers through Cooperative Tetrathiafulvalene Radical Cation Dimerization (pages 575–584)

      Jia Tian, Yu-Di Ding, Tian-You Zhou, Dr. Kang-Da Zhang, Prof. Xin Zhao, Dr. Hui Wang, Prof. Dan-Wei Zhang, Prof. Yi Liu and Prof. Zhan-Ting Li

      Article first published online: 2 DEC 2013 | DOI: 10.1002/chem.201302951

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      Radical-cation-based assembly: Tetrathiafulvalene radical cation units attached to a tetraphenylmethane framework undergo strong intermolecular stacking in both less polar organic and polar aqueous media, leading to the formation of new 3D spherical supramolecular polymers (see figure).

    20. Electrocatalytic Activity

      Pt-Pd-Co Trimetallic Alloy Network Nanostructures with Superior Electrocatalytic Activity towards the Oxygen Reduction Reaction (pages 585–590)

      Dr. Xinyu Liu, Gengtao Fu, Yu Chen, Prof. Yawen Tang, Peiliang She and Tianhong Lu

      Article first published online: 29 NOV 2013 | DOI: 10.1002/chem.201302834

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      Network metals: Three-dimensional Pt-Pd-Co trimetallic alloy network nanostructures are synthesized by using K2PtCl4/K3Co(CN)6–K2PdCl4/K3Co(CN)6 mixed cyanogels as the reaction precursor in the absence of surfactants and templates at room temperature (see figure). The Pt-Pd-Co nanostructures show superior electrocatalytic activity and stability compared with commercially available Pt black in the oxygen reduction reaction.

    21. Asymmetric Synthesis

      Asymmetric α-Hydroxylation of a Lactone with Vinylogous Pyridone by Using a Guanidine–Urea Bifunctional Organocatalyst: Catalytic Enantioselective Synthesis of a Key Intermediate for (20S)-Camptothecin Analogues (pages 591–597)

      Tatsuya Watanabe, Minami Odagi, Kota Furukori and Prof. Dr. Kazuo Nagasawa

      Article first published online: 28 NOV 2013 | DOI: 10.1002/chem.201303633

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      Two is better than one! An enantioselective α-hydroxylation of a lactone with a vinylogous pyridone structure has been achieved using a guanidine–urea bifunctional organocatalyst. The hydroxylation product, which is a key synthetic intermediate of (20S)-camptothecin and its analogues, was obtained in 95 % yield with 84 % ee (see scheme; CHP=cumene hydroperoxide).

    22. Fullerenes

      Highly Curved Bowl-Shaped Fragments of Fullerenes: Synthesis, Structural Analysis, and Physical Properties (pages 598–608)

      Min-Kuan Chen, Hsin-Ju Hsin, Dr. Tsun-Cheng Wu, Bo-Yan Kang, Yen-Wei Lee, Prof. Ming-Yu Kuo and Prof. Yao-Ting Wu

      Article first published online: 5 DEC 2013 | DOI: 10.1002/chem.201303357

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      Ahead of the curve: Highly curved bowl-shaped fragments of fullerenes were prepared under mild conditions. These molecules have a maximum π-orbital axis vector pyramidalization angle up to 12.9°, which exceeds that of C60 (11.6°), and they are the most curved π-bowls that map onto fullerenes. These bowls possess very high bowl-to-bowl inversion barriers, and they can be regarded as static bowls at room temperature (see figure).

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