Chemistry - A European Journal

Cover image for Vol. 15 Issue 28

July 13, 2009

Volume 15, Issue 28

Pages 6767–6987

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    8. Preview
    1. Cover Picture: Role of the Support in Catalysis: Activation of a Mononuclear Ruthenium Complex for Ethene Dimerization by Chemisorption on Dealuminated Zeolite Y (Chem. Eur. J. 28/2009) (page 6767)

      Isao Ogino and Bruce C. Gates

      Version of Record online: 6 JUL 2009 | DOI: 10.1002/chem.200990103

      Thumbnail image of graphical abstract

      The catalyst support plays several important roles, as discussed by I. Ogino and B. C. Gates in their Full Paper on page 6827 ff. A mononuclear ruthenium complex with one acac and two ethene ligands is bonded to an Al site of dealuminated zeolite Y by two Ru[BOND]O bonds (shown schematically). The Al site of the zeolite withdraws electron density from the supported [Ru(acac)(C2H4)2]+ species via the metal–zeolite bonds, which results in activation of the supported ruthenium complex to facilitate catalytic ethene dimerization.

  2. Graphical Abstract

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

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

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

      N-Heteroacenes (pages 6780–6789)

      Uwe H. F. Bunz

      Version of Record online: 23 JUN 2009 | DOI: 10.1002/chem.200900990

      Thumbnail image of graphical abstract

      Aromatic or not? An account of the coexistence of formally antiaromatic 4n π heterocycles and their 4n+2 π perimeters is presented. In a significant number of cases both the formally antiaromatic and the aromatic species are known and have been isolated and investigated. In the diazatetracene case both species are stable, isolable, and interconvertible (see scheme).

  5. Communications

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

      First Enantioselective Synthesis of (R)-Convolutamydine B and E with N-(Heteroarenesulfonyl)prolinamides (pages 6790–6793)

      Noriyuki Hara, Shuichi Nakamura, Norio Shibata and Takeshi Toru

      Version of Record online: 5 JUN 2009 | DOI: 10.1002/chem.200900944

      Thumbnail image of graphical abstract

      Crossed-aldol reaction: The synthesis of (R)-convolutamydine E has been achieved by the crossed-aldol reaction of acetaldehyde with 4,6-dibromoisatin (1: X = Y = Br) by using a bifunctional organocatalyst. This strategy allows the enantioselective synthesis of (R)-convolutamydine E derivatives and convolutamydine B.

    2. Helical Structures

      Double Helices with a Controlled Helicity Composed of Biphenol-Derived Phosphoric Acid Diesters (pages 6794–6798)

      Hidekazu Yamada, Katsuhiro Maeda and Eiji Yashima

      Version of Record online: 16 JUN 2009 | DOI: 10.1002/chem.200901075

      Thumbnail image of graphical abstract

      Novel artificial homo- and hetero-double helices were constructed by utilizing a specific self-assembly property of biphenol-derived phosphoric acid diesters, whose helical sense was controlled by chiral substituents introduced onto the phenylene unit as the linker moiety (see picture). Strong chiral amplification was observed during the double helix formation between chiral and achiral strands.

    3. Oxidation Reactions

      Efficient Reoxidation of Palladium by a Hybrid Catalyst in Aerobic Palladium-Catalyzed Carbocyclization of Enallenes (pages 6799–6801)

      Eric V. Johnston, Erik A. Karlsson, Staffan A. Lindberg, Björn Åkermark and Jan-E. Bäckvall

      Version of Record online: 19 JUN 2009 | DOI: 10.1002/chem.200900980

      Thumbnail image of graphical abstract

      Reoxidation: Smooth palladium-catalyzed aerobic C[BOND]C bond formation takes place in essentially quantitative yield with a hybrid catalyst (see scheme, E=CO2Me, R=R′=Me or R,R′=(CH2)5) through facilitated electron transfer from reduced palladium to molecular oxygen.

    4. Anticancer Agents

      A “Dual-Function” Photocage Releasing Nitric Oxide and an Anthrylmethyl Cation with a Single Wavelength Light (pages 6802–6806)

      Elisa Vittorino, Enzo Cicciarella and Salvatore Sortino

      Version of Record online: 19 JUN 2009 | DOI: 10.1002/chem.200901037

      Thumbnail image of graphical abstract

      A novel photocage able to generate two potential anticancer species, such as nitric oxide and an organic carbocation, under excitation by a single wavelength of light has been successfully designed and synthesized (see figure). This photocage satisfies a number of key criteria for potential biological applications, including stability in the dark, satisfactory photochemistry, adequate absorption at wavelengths longer than 300 nm, and a high decaging rate constant.

    5. Asymmetric Catalysis

      Highly Enantioselective Michael Addition of Malonate Derivatives to Enones Catalyzed by an N,N′-Dioxide–Scandium(III) Complex (pages 6807–6810)

      Donghui Chen, Zhenling Chen, Xiao Xiao, Zhigang Yang, Lili Lin, Xiaohua Liu and Xiaoming Feng

      Version of Record online: 10 JUN 2009 | DOI: 10.1002/chem.200901157

      Thumbnail image of graphical abstract

      A highly enantioselective Michael addition of malonate derivatives to chalcone derivatives catalyzed by an N,N′-dioxide–ScIII complex was developed, which tolerated a broad range of substrates in moderate to excellent yield with 96–99 % ee. The reaction proceeded well in EtOH or water and could be scaled to grams in good yield with 98 % ee using only 1 mol % ligand L–scandium(III) complex as a catalyst (see scheme).

    6. Natural Products

      A New and Flexible Synthesis of 4-Hydroxypyridines: Rapid Access to Caerulomycins A, E and Functionalized Terpyridines (pages 6811–6814)

      Jyotirmayee Dash and Hans-Ulrich Reissig

      Version of Record online: 16 JUN 2009 | DOI: 10.1002/chem.200900939

      Thumbnail image of graphical abstract

      Simple, but yet unknown: 1,3-Diketones, ammonia, and carboxylic acids are the precursors for the efficient synthesis of 4-hydroxypyridines and the corresponding nonaflate derivatives. This provides simple and practical access to a variety of highly substituted pyridine derivatives, including antibiotic natural products such as caerulomycins A, E and functionalized terpyridines (see scheme).

    7. Organocatalysis

      Asymmetric Organocatalytic Four-Component Quadruple Domino Reaction Initiated by Oxa-Michael Addition of Alcohols to Acrolein (pages 6815–6818)

      Fang-Lin Zhang, Ai-Wen Xu, Yue-Fa Gong, Mo-Hui Wei and Xiang-Liang Yang

      Version of Record online: 19 JUN 2009 | DOI: 10.1002/chem.200900613

      Thumbnail image of graphical abstract

      Four-component, quadruple cascade, one catalyst: An asymmetric four-component (ABC2) quadruple cascade reaction initiated by oxa-Michael addition of aliphatic alcohols to acrolein is reported (see scheme) to provide high yields of trisubstituted highly functionalized cyclohexene carbaldehydes with excellent diastereomeric and complete enantiomeric control. This process can be explained by an iminium (Im)–enamine (En)–iminium (Im)–enamine (En) sequence mechanism.

  6. Full Papers

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

      Precursor and Solvent Effects in the Nonhydrolytic Synthesis of Complex Oxide Nanoparticles for Bioimaging Applications by the Ether Elimination (Bradley) Reaction (pages 6820–6826)

      Robert Pazik, Renata Tekoriute, Sebastian Håkansson, Rafal Wiglusz, Wieslaw Strek, Gulaim A. Seisenbaeva, Yurii K. Gun'ko and Vadim G. Kessler

      Version of Record online: 19 JUN 2009 | DOI: 10.1002/chem.200900836

      Thumbnail image of graphical abstract

      Best crystallinity of the oxide particles produced by ether elimination reaction (Bradley reaction) is achieved on application of aprotic ketone solvents, for example, acetophenone, and of smallest possible alkoxide groups. The particles produced are biocompatible and their optical properties can easily be controlled through doping with rare earth cations. Distribution of Eu-doped BaTiO3 particles demonstrates their facile uptake by plants with enhanced concentration within the cell membranes (see scheme).

    2. Heterogeneous Catalysts

      Role of the Support in Catalysis: Activation of a Mononuclear Ruthenium Complex for Ethene Dimerization by Chemisorption on Dealuminated Zeolite Y (pages 6827–6837)

      Isao Ogino and Bruce C. Gates

      Version of Record online: 19 JUN 2009 | DOI: 10.1002/chem.200900927

      Thumbnail image of graphical abstract

      Many roles make zeolite work: Understanding the roles of the support in supported metal complex catalysts is challenging because of the structural nonuniformity of supported metal complexes. By taking advantage of the uniformity of zeolite-supported mononuclear ruthenium complexes and varying the ratios of chemisorbed to physisorbed species, the roles of the zeolite in the catalytic dimerization of ethene are demonstrated (see scheme).

    3. Host–Guest Chemistry

      Dynamic Molecular Tweezers Composed of Dibenzocyclooctatetraene Units: Synthesis, Properties, and Thermochromism in Host–Guest Complexes (pages 6838–6847)

      Tomohiko Nishiuchi, Yoshiyuki Kuwatani, Tohru Nishinaga and Masahiko Iyoda

      Version of Record online: 5 JUN 2009 | DOI: 10.1002/chem.200900623

      Thumbnail image of graphical abstract

      Tunable binding ability! Dynamic molecular tweezers (DMTs, see figure) composed of dibenzocyclooctatetraene units show unique binding abilities. Substituents on the cyclooctatetraene rings affect the electrostatic potential surfaces of the molecule and markedly change the binding abilities of DMTs. Furthermore, solutions of DMTs and DDQ in CHCl3 show thermochromism that depends on the DMT binding ability.

    4. Ion Pairing

      Ion Pairing and Salt Structure in Organic Salts through Diffusion, Overhauser, DFT and X-ray Methods (pages 6848–6862)

      Aitor Moreno, Paul S. Pregosin, Luis F. Veiros, Alberto Albinati and Silvia Rizzato

      Version of Record online: 5 JUN 2009 | DOI: 10.1002/chem.200900021

      Thumbnail image of graphical abstract

      Too salty? Pulsed gradient spin-echo (PGSE) diffusion data for brucinium (see figure) and carbocation salts in different solvents show strong ion pairing in CDCl3, intermediate in CD2Cl2 and little in [D6]acetone. 1H, 19F HOESY data (HOESY: heteronuclear Overhauser effect spectroscopy) for the carbocations reveal marked changes in the relative positions of the anions.

    5. Structure Analysis

      Capped Subporphyrins (pages 6863–6876)

      Yasuhide Inokuma and Atsuhiro Osuka

      Version of Record online: 5 JUN 2009 | DOI: 10.1002/chem.200900879

      Thumbnail image of graphical abstract

      Caps off! Capped subporphyrins were prepared by convex-face selective capping reactions of meso-(3-aminophenyl)subporphyrin and tripodalaldehydes. These caged subporphyrins exhibit unique properties, such as solvent encapsulation and spiral interconversion (see figure).

    6. Mass-Control Systems

      Borate-Driven Gatelike Scaffolding Using Mesoporous Materials Functionalised with Saccharides (pages 6877–6888)

      Elena Aznar, Carmen Coll, M. Dolores Marcos, Ramón Martínez-Máñez, Félix Sancenón, Juan Soto, Pedro Amorós, Joan Cano and Eliseo Ruiz

      Version of Record online: 2 JUN 2009 | DOI: 10.1002/chem.200900090

      Thumbnail image of graphical abstract

      Mass transport controlled by small anions: Gatelike scaffolding based on mesoporous materials functionalised with saccharides has been developed (see graphic). They are able to control the release of the cargo in water by using the small borate anion and changes in the pH as stimuli.

    7. Ionic Liquids

      Probing Intermolecular Interactions in Ionic Liquid–Water Mixtures by Near-Infrared Spectroscopy (pages 6889–6893)

      Bo Wu, Yang Liu, Yumei Zhang and Huaping Wang

      Version of Record online: 2 JUN 2009 | DOI: 10.1002/chem.200802742

      Thumbnail image of graphical abstract

      Insight into the interactions between ionic liquids (ILs), 1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim]BF4, and 1-allyl-3-methylimidazolium chloride, [Amim]Cl, and water is presented using near-infrared (NIR) spectroscopic measurements. Distinct differences were found in the NIR spectra of pure [Amim]Cl and [Bmim]BF4, whereby we propose optimized conformations.

    8. Carbohydrate Chemistry

      Evidence for Endocyclic Cleavage of Conformationally Restricted Glycopyranosides (pages 6894–6901)

      Shino Manabe, Kazuyuki Ishii, Daisuke Hashizume, Hiroyuki Koshino and Yukishige Ito

      Version of Record online: 16 JUN 2009 | DOI: 10.1002/chem.200900064

      Thumbnail image of graphical abstract

      Splitting sugars: Intra- and intermolecular Friedel–Crafts reactions, chloride addition, and reduction of the generated cation were used to obtain evidence for the endocyclic cleavage of conformationally restricted pyranosides in the chair form (see scheme; Bn: benzyl).

    9. Nanocomposites

      Fabrication of Luminescent CdS Nanoparticles on Short-Peptide-Based Hydrogel Nanofibers: Tuning of Optoelectronic Properties (pages 6902–6909)

      Goutam Palui, Jayanta Nanda, Sudipta Ray and Arindam Banerjee

      Version of Record online: 19 JUN 2009 | DOI: 10.1002/chem.200900149

      Thumbnail image of graphical abstract

      Nanoparticles within a gel: CdS nanoparticles can be immobilized within the gel network obtained from short synthetic self-assembling peptides (see picture). These CdS nanoparticles are incorporated as a well-defined array on the surface of gel nanofibers. The optoelectronic properties of the CdS nanoparticles are tuned upon their deposition on the gel nanofibers.

    10. Natural Products

      A Stereodivergent Strategy to Both Product Enantiomers from the Same Enantiomer of a Stereoinducing Catalyst: Agelastatin A (pages 6910–6919)

      Barry M. Trost and Guangbin Dong

      Version of Record online: 16 JUN 2009 | DOI: 10.1002/chem.200900794

      Thumbnail image of graphical abstract

      Pyrroles andN-alkoxyamides have been developed as new classes of nucleophiles for palladium-catalyzed AAA reactions. Either regioisomer of the pyrrolo-piperazinones could be accessed with high efficiency and enantioselectivity. Towards the end, we developed two different strategies for the total syntheses of both enantiomers of agelastatin A using the same enantiomer of a chiral palladium catalyst.

    11. Dynamic Networks

      Bond Scrambling and Network Elasticity (pages 6920–6925)

      Alberto Ciferri

      Version of Record online: 4 JUN 2009 | DOI: 10.1002/chem.200802746

      Thumbnail image of graphical abstract

      Bond scrambling occurs in the null-stress and in the deformed state of a supramolecular network. Strain-dependent rates of bond rupture and reformation favor compliance when stress is applied and recovery when stress is released. Concepts based on the composite network theory and adaptive features of supramolecular polymers are highlighted.

    12. Host–Guest Chemistry

      Electron Density Shift in Imidazolium Derivatives upon Complexation with Cucurbit[6]uril (pages 6926–6931)

      Viktor Kolman, Radek Marek, Zora Strelcova, Petr Kulhanek, Marek Necas, Jan Svec and Vladimir Sindelar

      Version of Record online: 9 JUN 2009 | DOI: 10.1002/chem.200900570

      Thumbnail image of graphical abstract

      Search for cavities: The complexation between 1-alkyl-3-methylimidazolium guests and cucurbit[6]uril are accompanied by an electron density shift in the imidazolium ring. The modes of binding between the guests and host cavity are dependent on the length of alkyl chain (see figure).

    13. Heterohexanuclear Complexes

      Heterohexanuclear (Cu3Fe3) Complexes of Substituted Hexaazatrinaphthylene (HATN) Ligands: Twofold BF4 Association in the Solid and Stepwise Oxidation (3e) or Reduction (2e) to Spectroelectrochemically Characterized Species (pages 6932–6939)

      Sayak Roy, Biprajit Sarkar, Carole Duboc, Jan Fiedler, Orkan Sarper, Falk Lissner, Shaikh M. Mobin, Goutam Kumar Lahiri and Wolfgang Kaim

      Version of Record online: 4 JUN 2009 | DOI: 10.1002/chem.200802655

      Thumbnail image of graphical abstract

      Up to six redox states can be identified for complexes in which three copper(I) ions connect three oxidizable 1,1′-diphosphinoferrocene units with multiply reducible central tris-bidentate hexaazatrinaphthylene ligands (see graphic).

    14. Metallomacrocycles

      The Assembly of Macrocyclic Bis- and Tetra-β-lactams with Embedded Platinum or Palladium Square-Planar Centers (pages 6940–6952)

      Daniel Pellico, Mar Gómez-Gallego, Pedro Ramírez-López, María José Mancheño, Miguel A. Sierra and M. Rosario Torres

      Version of Record online: 5 JUN 2009 | DOI: 10.1002/chem.200900374

      Thumbnail image of graphical abstract

      The right hole: A series of mono- and bimetallic Pd and Pt macrocyclic β-lactam molecules has been synthesized, the structures of which combine the β-lactam moiety with transition-metal fragments with a defined cis-square-planar geometry and constitute a new class of metal-assembled cavities involving molecules with biological relevance as building blocks (see scheme). By combining the adequate ligands, metallic fragments, and tuning the reaction conditions, different mono- and bimetallic macrocyclic β-lactam cavities can be selectively obtained.

    15. Hydrogenation

      Efficient and Practical Arene Hydrogenation by Heterogeneous Catalysts under Mild Conditions (pages 6953–6963)

      Tomohiro Maegawa, Akira Akashi, Kiichiro Yaguchi, Yohei Iwasaki, Masahiro Shigetsura, Yasunari Monguchi and Hironao Sajiki

      Version of Record online: 9 JUN 2009 | DOI: 10.1002/chem.200900361

      Thumbnail image of graphical abstract

      Make cyclohexanes easily! An efficient and practical procedure for hydrogenation of arenes under mild conditions has been developed. The method has a wide applicability of substrates, including heteroarenes and phenols. The use of reusable heterogeneous catalysts and of iPrOH as a solvent offers the promise of an environmentally benign and industrially applicable method.

    16. Aromaticity

      Double Aromaticity and Ring Currents in All-Carbon Rings (pages 6964–6972)

      Patrick W. Fowler, Noriyuki Mizoguchi, David E. Bean and Remco W. A. Havenith

      Version of Record online: 5 JUN 2009 | DOI: 10.1002/chem.200900322

      Thumbnail image of graphical abstract

      Seeing double? The double/mixed aromatic character of neutral carbon rings is demonstrated by visualisation of con- and counter-rotating ring currents arising from two orthogonal “π” systems (see figure). Nested Frost–Musulin diagrams and angular momentum rules give a simple explanation.

    17. Mesoporous Materials

      Multifunctional Hydroxyapatite Nanofibers and Microbelts as Drug Carriers (pages 6973–6982)

      Zhiyao Hou, Piaoping Yang, Hongzhou Lian, Lili Wang, Cuimiao Zhang, Chunxia Li, Ruitao Chai, Ziyong Cheng and Jun Lin

      Version of Record online: 3 JUN 2009 | DOI: 10.1002/chem.200900269

      Thumbnail image of graphical abstract

      Luminescent and mesoporous europium-doped hydroxyapatite (HAp:Eu3+) nanofibers and microbelts (see depicted SEM images) have been prepared by a combination of sol–gel and electrospinning processes with a cationic surfactant as the template. These multifunctional materials can be used as drug carriers, and drug release can be easily tracked and monitored by means of the change in Eu3+ luminescence intensity with released amount of drug.

  7. Preview

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    8. Preview
    1. Preview: Chem. Eur. J. 29/2009 (page 6987)

      Version of Record online: 6 JUL 2009 | DOI: 10.1002/chem.200990106

SEARCH

SEARCH BY CITATION