Chemistry - A European Journal

Cover image for Vol. 18 Issue 49

December 3, 2012

Volume 18, Issue 49

Pages 15557–15885

  1. Cover Pictures

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Communications
    6. Full Papers
    1. You have free access to this content
      Cover Picture: Catalytic and Mechanistic Insights of the Low-Temperature Selective Oxidation of Methane over Cu-Promoted Fe-ZSM-5 (Chem. Eur. J. 49/2012) (page 15557)

      Dr. Ceri Hammond, Dr. Robert L. Jenkins, Dr. Nikolaos Dimitratos, Dr. Jose Antonio Lopez-Sanchez, Dr. Mohd Hasbi ab Rahim, Dr. Michael M. Forde, Adam Thetford, Dr. Damien M. Murphy, Dr. Henk Hagen, Dr. Eric E. Stangland, Prof. Jacob M. Moulijn, Dr. Stuart H. Taylor, Dr. David J. Willock and Prof. Graham J. Hutchings

      Version of Record online: 23 NOV 2012 | DOI: 10.1002/chem.201290208

      Thumbnail image of graphical abstract

      Methane to methanolconversion presents one of the most challenging targets in catalysis. Recently, it was demonstrated that an iron- and copper-containing MFI-type zeolite is able to catalytically convert methane to methanol in an aqueous solvent at selectivities above 90 % by using H2O2 as the terminal oxidant. To facilitate understanding of the precise roles of the catalyst and the full mechanistic cycle, C. Hammond, G. J. Hutchings et al. present an in-depth study of the kinetic parameters and mechanistic features of this system in their Full Paper on page 15735 ff. The catalytic system in question results in a low-energy methane activation route, and allows selective C1-oxidation to occur under mild reaction conditions.

    2. You have free access to this content
      Inside Cover: Narcissistic versus Social Self-Sorting of Oligophenyleneethynylene Derivatives: From Isodesmic Self-Assembly to Cooperative Co-Assembly (Chem. Eur. J. 49/2012) (page 15558)

      Dr. María José Mayoral, Christina Rest, Jennifer Schellheimer, Dr. Vladimir Stepanenko and Dr. Gustavo Fernández

      Version of Record online: 23 NOV 2012 | DOI: 10.1002/chem.201290209

      Thumbnail image of graphical abstract

      Narcissistic versus social! In their Communication on page 15607 ff., G. Fernández et al. report on the self-assembly of two structurally related oligophenyleneethynylene (OPE) derivatives featuring polar or nonpolar peripheral chains and their remarkable narcissistic versus social self-sorting behaviour in aqueous media that can be controlled by concentration and solvent changes. Between 0.01 and 0.1 mM the mixture of both OPEs self-assembles into independent spherical aggregates, whereas a slight increase in concentration to 1 mM induces a co-assembly process, giving rise to large ribbon-like aggregates.

  2. Graphical Abstract

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

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

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Communications
    6. Full Papers
    1. CO2 Fixation

      Synthesis of Oxazolidinones by Efficient Fixation of Atmospheric CO2 with Propargylic Amines by using a Silver/1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) Dual-Catalyst System (pages 15578–15581)

      Prof. Dr. Masahiro Yoshida, Tomotaka Mizuguchi and Prof. Dr. Kozo Shishido

      Version of Record online: 7 NOV 2012 | DOI: 10.1002/chem.201203366

      Thumbnail image of graphical abstract

      This'll fix it: Efficient fixation of atmospheric CO2 has been achieved by the reaction of propargylic amines with a silver/DBU dual-catalyst system (see scheme). Various oxazolidinones were synthesized in moderate to good yields by using substituted propargylic amines.

    2. Synthetic Methods

      Transition-Metal-Free Synthesis of Aryl-Substituted tert-Butyl Ynol Ethers through Addition/Elimination Substitution at an sp Centre (pages 15582–15585)

      Vincent J. Gray, Dr. Ben Slater and Dr. Jonathan D. Wilden

      Version of Record online: 19 OCT 2012 | DOI: 10.1002/chem.201203015

      Thumbnail image of graphical abstract

      Nucleophilic attack of an alkoxide on an alkynyl sulfonamide leads to displacement of the sulfonamide at the sp centre and isolation of the ynol ether in good yield in a single operation (see scheme). The mechanistic pathway has been probed by the use of coordinating additives, 13C-labelling experiments and ab initio calculations, which indicated that an addition/elimination mechanism is in operation.

    3. Asymmetric Catalysis

      Highly Enantioselective Imine Hydrogenation Catalyzed by Ruthenium Phosphane–Phosphite Diamine Complexes (pages 15586–15591)

      Mónica Vaquero, Dr. Andrés Suárez, Dr. Sergio Vargas, Dr. Giovanni Bottari, Dr. Eleuterio Álvarez and Dr. Antonio Pizzano

      Version of Record online: 7 NOV 2012 | DOI: 10.1002/chem.201203193

      Thumbnail image of graphical abstract

      Mildly does it: A highly enantioselective catalyst for the hydrogenation of N-aryl imines is described (see scheme). This catalyst offers practical advantages because it operates under very mild conditions and is based on an Ru complex with a diamine as the sole chiral ligand.

    4. Arylation Reactions

      A Selective Palladium-Catalyzed Carbonylative Arylation of Aryl Ketones to Give Vinylbenzoate Compounds (pages 15592–15597)

      Johannes Schranck, Dr. Anis Tlili, Dr. Helfried Neumann, Pamela G. Alsabeh, Prof. Dr. Mark Stradiotto and Prof. Dr. Matthias Beller

      Version of Record online: 9 NOV 2012 | DOI: 10.1002/chem.201202895

      Thumbnail image of graphical abstract

      Preparation of enols: When treated with [{Pd(cinnamyl)Cl}2]/cataCXium A (nBuPAd2, Ad=adamantyl) under an atmosphere of CO, aryl ketones react with aryl halides in a carbonylative C[BOND]O coupling reaction to form (Z)-vinyl benzoates (see scheme).

    5. Micelles

      A Unique Ionic Liquid with Amphiphilic Properties That Can Form Reverse Micelles and Spontaneous Unilamellar Vesicles (pages 15598–15601)

      Cristian C. Villa, Dr. Fernando Moyano, Prof. Dr. Marcelo Ceolin, Prof. Dr. Juana J. Silber, Dr. R. Darío Falcone and Prof. Dr. N. Mariano Correa

      Version of Record online: 5 NOV 2012 | DOI: 10.1002/chem.201203246

      Thumbnail image of graphical abstract

      Catanionic surfactants: The synthesis of a new surfactant ionic liquid with unique properties is described. The formation of reverse micelles in benzene and large unilamellar vesicles, formed spontaneously without the help of any mechanical of chemistry methods, in water is demonstrated by using dynamic light scattering and small-angle X-ray scattering techniques (see scheme).

    6. Heterocycle Synthesis

      Propargyl Hydrazides: Synthesis and Conversion Into Pyrazoles Through Hydroamination (pages 15602–15606)

      Prof. Dr. Mitsuhiro Yoshimatsu, Katsuki Ohta and Nami Takahashi

      Version of Record online: 9 NOV 2012 | DOI: 10.1002/chem.201202828

      Thumbnail image of graphical abstract

      Pyrazoles direct: Propargyl alcohols undergo hydrazination when treated with p-tosyl hydrazide in the presence of catalytic amounts of either Sc(OTf)3 or La(OTf)3 (see scheme; Tf=trifluoromethanesulfonyl). Propargyl hydrazides are converted into either N-tosyl or N-H pyrazoles when treated with an acid or a base, respectively. The one-step acid-catalyzed hydrazination/cyclization of propargyl alcohols directly affords pyrazoles in high yields.

    7. Self-Sorting

      Narcissistic versus Social Self-Sorting of Oligophenyleneethynylene Derivatives: From Isodesmic Self-Assembly to Cooperative Co-Assembly (pages 15607–15611)

      Dr. María José Mayoral, Christina Rest, Jennifer Schellheimer, Dr. Vladimir Stepanenko and Dr. Gustavo Fernández

      Version of Record online: 6 NOV 2012 | DOI: 10.1002/chem.201202367

      Thumbnail image of graphical abstract

      Narcissistic versus social! The self-assembly of two structurally related oligophenyleneethynylene derivatives featuring polar or nonpolar peripheral chains is reported. Their remarkable narcissistic versus social self-sorting behaviour in aqueous media can be controlled by concentration and solvent changes (see figure).

    8. Macrocyclization

      Bending Rigid Molecular Rods: Formation of Oligoproline Macrocycles (pages 15612–15617)

      Dr. Conor C. G. Scully, Dr. Vishal Rai, Dr. Gennadiy Poda, Serge Zaretsky, Dr. Darcy C. Burns, Dr. R. Scott Houliston, Tiantong Lou and Prof. Dr. Andrei K. Yudin

      Version of Record online: 4 NOV 2012 | DOI: 10.1002/chem.201203266

      Thumbnail image of graphical abstract

      Bent but not broken: Cyclic oligoprolines are accessed in a reaction that effectively bends rigid oligoproline peptides (see scheme; TBDMS=tert-butyldimethylsilyl). The stitching is accomplished during macrocyclization enabled by aziridine aldehydes and isocyanides. Molecular modeling studies suggest that electrostatic attraction between the termini of the linear peptide is pivotal for macrocyclization. The macrocycles were studied by circular dichroism with a polyproline II structure being observed in larger macrocycles.

  5. Full Papers

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Communications
    6. Full Papers
    1. Peptides

      Copper, BDNF and Its N-terminal Domain: Inorganic Features and Biological Perspectives (pages 15618–15631)

      Dr. Alessio Travaglia, Prof. Diego La Mendola, Dr. Antonio Magrì, Prof. Vincenzo Giuseppe Nicoletti, Dr. Adriana Pietropaolo and Prof. Enrico Rizzarelli

      Version of Record online: 7 NOV 2012 | DOI: 10.1002/chem.201202775

      Thumbnail image of graphical abstract

      Key complex: Brain-derived neurotrophic factor (BDNF) N-terminal domain binds copper(II) with the involvement of His-1 α-amino group and Asp-3 carboxylate. The peptide encompassing the sequence 1–12 of the amino-terminal domain (BDNF(1–12)) of human BDNF is able to bind Cu2+. The predominant Cu2+ complex species, at physiological pH, is the [CuH−2L]2− in which the metal ion is bound to an amino group, two amide nitrogen atoms, and a carboxylate group (NH2, 2N, COOAsp) in a planar environment (see figure).

    2. Molecular Gauge Blocks

      Molecular Gauge Blocks for Building on the Nanoscale (pages 15632–15649)

      Dr. Sergio Grunder, Dr. Cory Valente, Dr. Adam C. Whalley, Dr. Srinivasan Sampath, Jürg Portmann, Dr. Youssry Y. Botros and Prof. J. Fraser Stoddart

      Version of Record online: 22 OCT 2012 | DOI: 10.1002/chem.201201985

      Thumbnail image of graphical abstract

      Walking along a fine line: The synthesis and characterization of a series of high-aspect-ratio oligoparaxylenes as molecular gauge blocks are reported. The lengths of the molecules range from 10 Å for the shortest member of the series with two phenylene rings up to 50 Å for the longest member with eleven phenylene units (see figure). Minimalistic design criteria led to a walk along a fine line between keeping the molecules slender, yet also rendering them soluble.

    3. Supramolecular Polymerization

      Supramolecular Polymerization at Low Monomer Concentrations: Enhancing Intermolecular Interactions and Suppressing Cyclization by Rational Molecular Design (pages 15650–15654)

      Yiliu Liu, Ruochen Fang, Xinxin Tan, Prof. Zhiqiang Wang and Prof. Xi Zhang

      Version of Record online: 15 OCT 2012 | DOI: 10.1002/chem.201202985

      Thumbnail image of graphical abstract

      Chaining up naphthalene: Long-chain water-soluble supramolecular polymers have been constructed at low monomer concentrations (see scheme). Naphthalene-based host-enhanced π–π interactions are used as the driving force of the supramolecular polymerization and the monomer structure strongly influences the efficiency of the supramolecular polymerization.

    4. Sensors

      Exceptional Blueshifted and Enhanced Aggregation-Induced Emission of Conjugated Asymmetric Triazines and Their Applications in Superamplified Detection of Explosives (pages 15655–15661)

      Zhong-Fu An, Chao Zheng, Dr. Run-Feng Chen, Jun Yin, Jian-Jian Xiao, Hui-Fang Shi, Ye Tao, Dr. Yan Qian and Prof. Wei Huang

      Version of Record online: 15 OCT 2012 | DOI: 10.1002/chem.201202337

      Thumbnail image of graphical abstract

      Out with a bang! Highly efficient, narrow, and blueshifted ultraviolet light emission was observed in solid films of donor–acceptor (D–A) asymmetrically conjugated triazine-based molecules. The special aggregation-induced emission of the molecular system allowed the triazine aggregates to show superamplified detection of picric acid with high quenching constants (>1.0×107M−1) and a low detection limit of 15 ppb (see figure).

    5. Polymers

      Functionalized Soft Nanoporous Materials through Supramolecular Assembly of End-Functionalized Polymer Blends (pages 15662–15668)

      Giyoung Song, Suk Man Cho, Hee Joon Jung, Richard Hahnkee Kim, Insung Bae, Hyungju Ahn, Dr. Du Yeol Ryu, Dr. June Huh and Dr. Cheolmin Park

      Version of Record online: 25 OCT 2012 | DOI: 10.1002/chem.201202685

      Thumbnail image of graphical abstract

      A well-organized, nanoporous, thin template was fabricated with control over both size and interdomain distance through conventional solution blending and spin-coating by using two mono-end-functionalized polymers. A simple solvent-vapor treatment not only improved the nanostructure formation, but also effectively removed one of the polymers, leading to a nanoporous soft template with rich end functionalities on the surface of the pores (see figure).

    6. Nanoparticles

      Alkylaminosilane-Assisted Simultaneous Etching and Growth Route to Synthesise Metal Nanoparticles Encapsulated by Silica Nanorattles (pages 15669–15675)

      Xiaoli Wu, Dr. Longfei Tan, Dr. Dong Chen, Xiaolong He, Dr. Huiyu Liu, Dr. Xianwei Meng and Prof. Fangqiong Tang

      Version of Record online: 16 OCT 2012 | DOI: 10.1002/chem.201201809

      Thumbnail image of graphical abstract

      Shake, rattle and roll: A simultaneous etching and growth strategy to prepare metal cores in silica nanorattles (SNs; gold: GESN; palladium: PESN) is presented (see figure). This is done by introducing a dual-functional alkylaminosilane to construct an etchable middle layer and to provide a reducing agent for the in situ growth of metal nanoparticles. (HSSS=hybrid solid silica spheres.)

    7. Drug Delivery

      Poly(acrylic acid)-Modified Fe3O4 Microspheres for Magnetic-Targeted and pH-Triggered Anticancer Drug Delivery (pages 15676–15682)

      Dr. Xiao-Jiao Kang, Dr. Yun-Lu Dai, Dr. Ping-An Ma, Dr. Dong-Mei Yang, Dr. Chun-Xia Li, Dr. Zhi-Yao Hou, Dr. Zi-Yong Cheng and Prof. Jun Lin

      Version of Record online: 18 OCT 2012 | DOI: 10.1002/chem.201202433

      Thumbnail image of graphical abstract

      Dual response: Monodisperse poly(acrylic acid)-modified Fe3O4 (PAA@Fe3O4) hybrid microspheres with dual responses (magnetic field and pH) were successfully fabricated (see figure). The drug release behavior was strongly dependent on pH value due to the unique properties of PAA. Furthermore, doxorubicin (DOX)-loaded PAA@Fe3O4 composites show an enhanced magnetically guided anticancer effect.

    8. Reaction Mechanisms

      Mechanistic Investigation of the Ruthenium–N-Heterocyclic-Carbene-Catalyzed Amidation of Amines with Alcohols (pages 15683–15692)

      Ilya S. Makarov, Dr. Peter Fristrup and Prof. Dr. Robert Madsen

      Version of Record online: 15 OCT 2012 | DOI: 10.1002/chem.201202400

      Thumbnail image of graphical abstract

      On the right pathway: Experimental and theoretical investigations indicate that the Ru-catalyzed amidation of amines with alcohols (see scheme) proceeds by alcohol coordination, β-hydride elimination, nucleophilic attack, and β-hydride elimination to the amide.

    9. Catalysts

      DNA-Directed Growth of Pd Nanocrystals on Carbon Nanotubes towards Efficient Oxygen Reduction Reactions (pages 15693–15698)

      Lian Ying Zhang, Dr. Chun Xian Guo, Dr. Zhiming Cui, Dr. Jun Guo, Prof. Zhili Dong and Prof. Chang Ming Li

      Version of Record online: 11 OCT 2012 | DOI: 10.1002/chem.201201571

      Thumbnail image of graphical abstract

      In the right direction: A facile approach to fabricate Pd-based catalysts in which DNA directs the growth of ultrasmall Pd nanocrystals uniformly distributed on carbon nanotubes (Pd/DNA–CNTs; see TEM image) is demonstrated. The Pd/DNA–CNT catalyst shows efficient performance and stability towards oxygen reduction reactions with good methanol tolerance.

    10. Amine–Borane Complexes

      Can an Amine Be a Stronger Acid than a Carboxylic Acid? The Surprisingly High Acidity of Amine–Borane Complexes (pages 15699–15705)

      Ana Martín-Sómer, Dr. Al Mokhtar Lamsabhi, Prof. Manuel Yáñez, Dr. Juan Z. Dávalos, Javier González, Rocío Ramos and Dr. Jean-Claude Guillemin

      Version of Record online: 11 OCT 2012 | DOI: 10.1002/chem.201202192

      Thumbnail image of graphical abstract

      It's all relative: The complexation of boranes to amines leads to a dramatic increase in the acidity of the amine. Thus, typical nitrogen bases, such as aniline, give amine–borane complexes, which are nitrogen-based acids that are as acidic as phosphoric acid in the gas phase.

    11. Imaging Agents

      Referenced Dual Pressure- and Temperature-Sensitive Paint for Digital Color Camera Read Out (pages 15706–15713)

      Dr. Lorenz H. Fischer, Cüneyt Karakus, Dr. Robert J. Meier, Prof. Dr. Nikolaus Risch, Prof. Dr. Otto S. Wolfbeis, Prof. Dr. Elisabeth Holder and Priv.-Doz. Dr. Michael Schäferling

      Version of Record online: 15 OCT 2012 | DOI: 10.1002/chem.201201358

      Thumbnail image of graphical abstract

      A life in color: A composite material for the simultaneous referenced sensing of barometric pressure and temperature can be read by a simple digital color camera. Three photoluminescent dyes (indicators for pO2 and T, as well as a reference), whose distinct emission maxima matched the RGB channels of the camera, were incorporated into the sensing layer. The distribution of pressure and temperature on the surface of the material was imaged.

    12. Cycloaddition

      Control of Light-Promoted [2+2] Cycloaddition Reactions by a Remote Ancillary Regulatory Group That Is Covalently Attached to Rhenium Rectangles (pages 15714–15721)

      Zong-Zhan Lu, Dr. Chung-Chou Lee, Dr. Murugesan Velayudham, Li-Wei Lee, Dr. Jing-Yun Wu, Ting-Shen Kuo and Prof. Dr. Kuang-Lieh Lu

      Version of Record online: 15 OCT 2012 | DOI: 10.1002/chem.201202301

      Thumbnail image of graphical abstract

      Regulatory affairs: A remote regulatory group in rhenium rectangles, [Re2(CO)6(L)(bpe)]2 (L=biimidazolate, bpe=trans-1,2-bis(4-pyridyl)ethylene), selectively controlled light-promoted [2+2] cycloaddition reactions at the reaction center.

    13. Photochemistry

      You have full text access to this OnlineOpen article
      Photochemistry of fac-[Re(bpy)(CO)3Cl] (pages 15722–15734)

      Dr. Shunsuke Sato, Dr. Yasuo Matubara, Dr. Kazuhide Koike, Dr. Magnus Falkenström, Dr. Tetsuro Katayama, Dr. Yukihide Ishibashi, Prof. Hiroshi Miyasaka, Dr. Seiji Taniguchi, Dr. Haik Chosrowjan, Prof. Noboru Mataga, Dr. Naoto Fukazawa, Prof. Shinya Koshihara, Prof. Ken Onda and Prof. Osamu Ishitani

      Version of Record online: 18 OCT 2012 | DOI: 10.1002/chem.201202734

      Thumbnail image of graphical abstract

      Time on our side: Photochemical ligand substitution and isomerization of fac-[Re(bpy)(CO)3Cl] (bpy=2,2′-bipyridine) with high-energy light are reported. The combination of steady-state irradiation, time-resolved (TR)-UV-visible, TR-IR, and TR-emission experiments gave detailed information on not only various excited states but also short-lived intermediates (see scheme).

    14. Oxidation

      Catalytic and Mechanistic Insights of the Low-Temperature Selective Oxidation of Methane over Cu-Promoted Fe-ZSM-5 (pages 15735–15745)

      Dr. Ceri Hammond, Dr. Robert L. Jenkins, Dr. Nikolaos Dimitratos, Dr. Jose Antonio Lopez-Sanchez, Dr. Mohd Hasbi ab Rahim, Dr. Michael M. Forde, Adam Thetford, Dr. Damien M. Murphy, Dr. Henk Hagen, Dr. Eric E. Stangland, Prof. Jacob M. Moulijn, Dr. Stuart H. Taylor, Dr. David J. Willock and Prof. Graham J. Hutchings

      Version of Record online: 13 NOV 2012 | DOI: 10.1002/chem.201202802

      Thumbnail image of graphical abstract

      Activate methane! A reaction network consisting of the activation of methane, the formation of an activated hydroperoxy species, and the by-production of hydroxyl radicals is presented (see scheme). The catalytic system results in a low-energy methane activation route, and allows selective C1-oxidation to proceed under intrinsically mild reaction conditions.

    15. Nanoparticles

      Far-Infrared-Assisted Preparation of a Graphene–Nickel Nanoparticle Hybrid for the Enrichment of Proteins and Peptides (pages 15746–15752)

      Dr. Weidong Qu, Dr. Huimin Bao, Dr. Luyan Zhang and Prof. Gang Chen

      Version of Record online: 30 OCT 2012 | DOI: 10.1002/chem.201202913

      Thumbnail image of graphical abstract

      Attractive hybrid: A graphene–nickel nanoparticle hybrid was prepared by the far-infrared-assisted synergistic reduction of graphene oxide and nickel(II) ions using hydrazine (see figure). It has been applied in the enrichment and identification of proteins and peptides in combination with mass spectrometry.

    16. Jahn—Teller Effect

      Jahn–Teller Effect in Circulenes: X-ray Diffraction Study of Coronene and Corannulene Radical Anions (pages 15753–15760)

      Dr. Alexander S. Filatov, Natalie J. Sumner, Sarah N. Spisak, Dr. Alexander V. Zabula, Andrey Yu. Rogachev and Prof. Marina A. Petrukhina

      Version of Record online: 15 OCT 2012 | DOI: 10.1002/chem.201202026

      Thumbnail image of graphical abstract

      Jahn–Teller distortions in nonplanar corannulene and planar coronene were detected in the solid state using single-crystal X-ray diffraction data. Cs and D2h symmetrical distortions fit the experimental data for C20H10.− and C24H12.−, respectively. The experimental data were supported by density functional theory calculations and continuous symmetry measure analysis.

    17. Natural Products

      Cyclohexyne Cycloinsertion in the Divergent Synthesis of Guanacastepenes (pages 15761–15771)

      Dr. Christian M. Gampe and Prof. Dr. Erick M. Carreira

      Version of Record online: 18 OCT 2012 | DOI: 10.1002/chem.201202222

      Thumbnail image of graphical abstract

      No strain, no gain! Studies toward the synthesis of the guanacastepene family of diterpenes are presented. The synthetic strategy relies on the use of cyclohexyne as the guanacastepene C-ring, which undergoes cycloinsertion to form the tricyclic carbon scaffold. A host of procedures developed for the diversification of the carbon core allowed the synthesis of guanacastepenes N and O and paved the way for the synthesis of guanacastepenes D and H.

    18. Amycolamicin: A Novel Broad-Spectrum Antibiotic Inhibiting Bacterial Topoisomerase (pages 15772–15781)

      Dr. Ryuichi Sawa, Dr. Yoshiaki Takahashi, Dr. Hideki Hashizume, Dr. Kazushige Sasaki, Dr. Yoshimasa Ishizaki, Maya Umekita, Dr. Masaki Hatano, Hikaru Abe, Dr. Takumi Watanabe, Naoko Kinoshita, Yoshiko Homma, Chigusa Hayashi, Kunio Inoue, Syunichi Ohba, Toru Masuda, Dr. Masayuki Arakawa, Dr. Yoshihiko Kobayashi, Dr. Masa Hamada, Dr. Masayuki Igarashi, Dr. Hayamitsu Adachi, Dr. Yoshio Nishimura and Dr. Yuzuru Akamatsu

      Version of Record online: 5 NOV 2012 | DOI: 10.1002/chem.201202645

      Thumbnail image of graphical abstract

      Equilibrium structure: Amycolamicin (AMM) was discovered as a new antibiotic and its absolute structure was determined. The pyranose ring named as amykitanose undergoes anomerization in methanol. AMM is effective against methicillin-resistant Staphylococcus aureus and its strains, which are resistant to known DNA gyrase inhibitors. AMM is a potent and selective inhibitor of DNA gyrase and it does not inhibit human topoisomerase II (see figure).

    19. Photochromism

      Photoinduced Fluorescence Activation and Nitric Oxide Release with Biocompatible Polymer Nanoparticles (pages 15782–15787)

      Dr. Erhan Deniz, Noufal Kandoth, Dr. Aurore Fraix, Dr. Venera Cardile, Dr. Adriana C. E. Graziano, Dr. Debora Lo Furno, Dr. Ruxandra Gref, Prof. Françisco M. Raymo and Prof. Salvatore Sortino

      Version of Record online: 25 OCT 2012 | DOI: 10.1002/chem.201202845

      Thumbnail image of graphical abstract

      Cyclodextrins: Photoresponsive polymer nanoparticles encapsulate fluorophore/photochrome dyads and nitric oxide photodonors within their hydrophobic interior and transport their cargo across the membrane of living cells. The two guests can be used simultaneously within the macromolecular host to activate fluorescence and release nitric oxide under optical control (see scheme).

    20. Cluster Compounds

      High Magnetic Moments in Manganese-Doped Silicon Clusters (pages 15788–15793)

      Dr. Vu Thi Ngan, Prof. Ewald Janssens, Dr. Pieterjan Claes, Prof. Jonathan T. Lyon, Dr. André Fielicke, Prof. Dr. Minh Tho Nguyen and Prof. Dr. Peter Lievens

      Version of Record online: 22 OCT 2012 | DOI: 10.1002/chem.201201839

      Thumbnail image of graphical abstract

      Good vibrations: The structural, electronic, and magnetic properties of SinMn+ clusters are studied using mass spectrometry and infrared spectroscopy in combination with density functional calculations. All the exohedral clusters are found to be substitutive derivatives of the bare Sin+1+ ions, whereas the endohedral clusters adopt fullerene-like structures. The clusters turn out to have high magnetic moments localized on Mn (see figure).

    21. Electron-Transfer Oxygenation

      Catalytic Electron-Transfer Oxygenation of Substrates with Water as an Oxygen Source Using Manganese Porphyrins (pages 15794–15804)

      Prof. Dr. Shunichi Fukuzumi, Takuya Mizuno and Tetsuya Ojiri

      Version of Record online: 5 NOV 2012 | DOI: 10.1002/chem.201202041

      Thumbnail image of graphical abstract

      Water source: With manganese(III)–porphyrins as catalysts and water as an oxygen source, catalytic electron-transfer oxygenation of substrates with a one-electron oxidant occurs efficiently. A rate-determining electron-transfer oxidation of manganese(III)–porphyrins produces manganese(V)–oxo–porphyrins that rapidly oxygenate the substrates (see scheme).

    22. Iron Complexes

      Heteroleptic FeII Complexes of 2,2′-Biimidazole and Its Alkylated Derivatives: Spin-Crossover and Photomagnetic Behavior (pages 15805–15815)

      Hoa V. Phan, Pradip Chakraborty, Meimei Chen, Yitzi M. Calm, Dr. Kirill Kovnir, Lawrence K. Keniley Jr., Jordan M. Hoyt, Elisabeth S. Knowles, Dr. Céline Besnard, Prof. Mark W. Meisel, Prof. Andreas Hauser, Prof. Catalina Achim and Prof. Michael Shatruk

      Version of Record online: 15 OCT 2012 | DOI: 10.1002/chem.201202045

      Thumbnail image of graphical abstract

      Persistent spin-crossover: Heteroleptic spin-crossover complexes of FeII were prepared by using a combination of tris(2-pyridylmethyl)amine and either 2,2′-biimidazole (BIM) or its alkylated derivatives. This set of ligands provides a promising platform for the preparation of spin-crossover complexes because N-alkylation of BIM has negligible effect on the ligand field strength. An abrupt spin transition with thermal hysteresis and LIESST effect were observed for the complex with alkylated BIM.

    23. C[BOND]H Activation

      Free-Amine-Directed Alkenylation of C(sp2)[BOND]H and Cycloamination by Palladium Catalysis (pages 15816–15821)

      Dr. Zunjun Liang, Long Ju, Yongju Xie, Lehao Huang and Prof. Yuhong Zhang

      Version of Record online: 10 OCT 2012 | DOI: 10.1002/chem.201202672

      Thumbnail image of graphical abstract

      Seven-membered cycloamination: A new protocol for the palladium-catalyzed free-amine-directed alkenylation of C(sp2)[BOND]H bonds and subsequent cycloamination is described (see scheme). Substituted biaryl-2-amines react with various alkenes to give the corresponding phenanthridines with exclusive regioselectivity. The use of α-branched styrenes leads to the formation of tricyclic compounds with a seven-membered amine ring.

    24. Amino Acids

      Quaternary Chiral β2,2-Amino Acids with Pyridinium and Imidazolium Substituents (pages 15822–15830)

      Lara Mata, Prof. Alberto Avenoza, Dr. Jesús H. Busto, Dr. Francisco Corzana and Prof. Jesús M. Peregrina

      Version of Record online: 12 OCT 2012 | DOI: 10.1002/chem.201202096

      Thumbnail image of graphical abstract

      Chiral β2,2-amino acids: Nitrogen-containing aromatic heterocycles were used as nucleophiles in the opening reaction of cyclic sulfamidates to obtain a new family of chiral β2,2-amino acids with pyridinium and imidazolium substituents, which show a rigid N-CH2-C-N+ dihedral angle due to the gauche effect. These chiral imidazolium derivatives open the way to the synthesis of new chiral N-heterocyclic carbenes.

    25. Metal–Organic Frameworks

      The Role of Pd2+/Pd0 in Hydrogenation by [Pd(2-pymo)2]n: An X-ray Absorption and IR Spectroscopic Study (pages 15831–15837)

      Sabine Schuster, Prof. Dr. Elias Klemm and Prof. Dr. Matthias Bauer

      Version of Record online: 16 OCT 2012 | DOI: 10.1002/chem.201202129

      Thumbnail image of graphical abstract

      Ex and in situ X-ray absorption and IR spectroscopy revealed that the active centers in hydrogenation of olefins by metal–organic frameworks (MOFs) [Pd(2-pymo)2]n (see figure) are Pd2+. Deactivation of the catalyst is caused by Pd0 formation following hydrogenation of the linker molecules, which leads to decomposition of the MOF structure.

    26. Structure–Activity Relationships

      Deprotonation-Induced Aromaticity Enhancement and New Conjugated Networks in meso-Hexakis(pentafluorophenyl)[26]hexaphyrin (pages 15838–15844)

      Won-Young Cha, Jong Min Lim, Dr. Min-Chul Yoon, Young Mo Sung, Byung Sun Lee, Sho Katsumata, Masaaki Suzuki, Hirotaka Mori, Prof. Dr. Yoshiya Ikawa, Prof. Dr. Hiroyuki Furuta, Prof. Dr. Atsuhiro Osuka and Prof. Dr. Dongho Kim

      Version of Record online: 15 OCT 2012 | DOI: 10.1002/chem.201200991

      Thumbnail image of graphical abstract

      Circuit tuning: Deprotonation causes significant structural deformations, which give rise to different and more effective π-conjugated circuits that have been found to be responsible for enhanced aromaticity (see figure). This work highlights the potential of the deprotonation strategy for tuning the electronic properties of expanded porphyrins.

    27. Fluorescence

      Diiminic Schiff Bases: An Intriguing Class of Compounds for a Copper-Nanoparticle-Induced Fluorescence Study (pages 15845–15855)

      Mainak Ganguly, Dr. Anjali Pal, Dr. Yuichi Negishi and Prof. Tarasankar Pal

      Version of Record online: 12 OCT 2012 | DOI: 10.1002/chem.201201242

      Thumbnail image of graphical abstract

      Making light of things: UV irradiation of alkaline diiminic Schiff base (DSB) solutions in the presence of water-soluble copper salts has been employed to produce copper nanoparticles (CuNPs). Fluorescence enhancement of the exposed DSBs was observed in the presence of in situ produced Cu0 (see figure).

    28. Reaction Mechanisms

      Study on 1,3,5-Triazine Chemistry in Dehydrocondensation: Gauche Effect on the Generation of Active Triazinylammonium Species (pages 15856–15867)

      Prof. Dr. Munetaka Kunishima, Takae Ujigawa, Yoshie Nagaoka, Chiho Kawachi, Dr. Kazuhito Hioki and Dr. Motoo Shiro

      Version of Record online: 11 OCT 2012 | DOI: 10.1002/chem.201202236

      Thumbnail image of graphical abstract

      The right approach! The structure–activity relationship of nitrogen-containing compounds including aliphatic tertiary amines in the reaction with 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) has been investigated (see scheme). The theory of “gauche β-alkyl group effect” proposed here provides useful guidelines for the preparation of triazine-based dehydrocondensation reagents (DMT-Ams) possessing various tertiary amine moieties.

    29. Asymmetric Catalysis

      Unraveling the Role of Water in the Stereoselective Step of Aqueous Proline-Catalyzed Aldol Reactions (pages 15868–15874)

      Dr. Jordi Ribas-Arino, Dr. Maria Angels Carvajal, Dr. Alain Chaumont and Dr. Marco Masia

      Version of Record online: 16 OCT 2012 | DOI: 10.1002/chem.201200007

      Thumbnail image of graphical abstract

      Different solvation patterns of the possible transition states have been traced as the source of the stereoselectivity of a key organocatalytic reaction—the proline-catalyzed asymmetric aldol condensation of propionaldehyde in water—by means of extensive first-principles molecular dynamics (MD) simulations. For example, the figure shows MD snapshots for SiSi (red line) and ReRe attack (blue line).

    30. Light Harvesting

      Wide-Range Light-Harvesting Donor–Acceptor Assemblies through Specific Intergelator Interactions via Self-Assembly (pages 15875–15885)

      Dr. Suman K. Samanta and Prof. Dr. Santanu Bhattacharya

      Version of Record online: 16 OCT 2012 | DOI: 10.1002/chem.201103855

      Thumbnail image of graphical abstract

      Join the cascade! Intergelator interactions between two p-phenylene–vinylene-based, low-molecular-mass gelators formed through donor–acceptor assembly have been demonstrated. A cascade energy transfer was described in an assembly of four different chromophores in a particular order. In this assembly, excitation at the first chromophore produces an emission at the fourth, thus establishing a wide-range light-harvesting process (see figure).

SEARCH

SEARCH BY CITATION