Angewandte Chemie International Edition

Cover image for Vol. 47 Issue 48

November 17, 2008

Volume 47, Issue 48

Pages 9161–9355

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. Corrigendum
    6. News
    7. Editorial
    8. Obituary
    9. Highlight
    10. Minireview
    11. Reviews
    12. Communications
    13. Preview
    1. Cover Picture: Molecular Factors of Catalytic Selectivity (Angew. Chem. Int. Ed. 48/2008) (page 9161)

      Gabor A. Somorjai and Jeong Y. Park

      Version of Record online: 12 NOV 2008 | DOI: 10.1002/anie.200890245

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      In situ molecular-level studies of catalytic reactions with scanning tunneling microscopy (STM) and sum frequency generation (SFG) vibrational spectroscopy have revealed seven molecular components of selectivity—surface structure, adsorbate-induced restructuring, adsorbate mobility, reaction intermediates, surface composition, charge transport, and oxidation states—for heterogeneous catalysis on metal single-crystal model surfaces and nanoparticles. For details, see the Review by G. A. Somorjai and J. Y. Park on page 9212 ff.

  2. Inside Cover

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. Corrigendum
    6. News
    7. Editorial
    8. Obituary
    9. Highlight
    10. Minireview
    11. Reviews
    12. Communications
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    1. Inside Cover: Real-Time Characterization of Formation and Breakup of Iridium Clusters in Highly Dealuminated Zeolite Y (Angew. Chem. Int. Ed. 48/2008) (page 9162)

      Alper Uzun and Bruce C. Gates

      Version of Record online: 12 NOV 2008 | DOI: 10.1002/anie.200890246

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      The cycle of formation and breakup of iridium clusters from mononuclear iridium diethylene complexes anchored in dealuminated Y zeolite is demonstrated by B. C. Gates and co-worker in their Communication on page 9245 ff. The picture represents the chemistry of cluster formation and breakup (a cycle, as the progress is reversible), with a background of the zeolite cage in which the chemistry takes place.

  3. Graphical Abstract

    1. Top of page
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    3. Inside Cover
    4. Graphical Abstract
    5. Corrigendum
    6. News
    7. Editorial
    8. Obituary
    9. Highlight
    10. Minireview
    11. Reviews
    12. Communications
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  4. Corrigendum

    1. Top of page
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    3. Inside Cover
    4. Graphical Abstract
    5. Corrigendum
    6. News
    7. Editorial
    8. Obituary
    9. Highlight
    10. Minireview
    11. Reviews
    12. Communications
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  5. News

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. Corrigendum
    6. News
    7. Editorial
    8. Obituary
    9. Highlight
    10. Minireview
    11. Reviews
    12. Communications
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  6. Editorial

    1. Top of page
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    4. Graphical Abstract
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      The Catalysis Society of Japan (CATSJ): History and Activities (pages 9180–9185)

      Yasuhiro Iwasawa, Masakazu Iwamoto, Takashi Deguchi, Yoshihiro Kubota, Masato Machida and Hiromi Yamashita

      Version of Record online: 12 NOV 2008 | DOI: 10.1002/anie.200804549

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      The Catalysis Society of Japan (CATSJ) celebrates its 50th anniversary this year. A brief history, summary of its activities, and outlook is presented.

  7. Obituary

    1. Top of page
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    4. Graphical Abstract
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    1. Jay Kazuo Kochi (1927–2008) (page 9186)

      Rajendra Rathore

      Version of Record online: 12 NOV 2008 | DOI: 10.1002/anie.200805187

  8. Highlight

    1. Top of page
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    4. Graphical Abstract
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    1. Zeolite Catalysis

      Morphology of and Catalysis in Single Crystals of Zeolites (pages 9188–9191)

      Robert A. Schoonheydt

      Version of Record online: 12 NOV 2008 | DOI: 10.1002/anie.200801327

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      Dynamic duo: Combined spectroscopy and microscopy techniques now allow the nature of active sites on zeolite catalysts to be determined in detail. For example, synchrotron IR microscopy reveals the dimeric carbocation of 4-fluorostyrene in a single crystal of ZSM-5 (see picture).

  9. Minireview

    1. Top of page
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    1. H2O2 Synthesis

      Palladium and Gold–Palladium Catalysts for the Direct Synthesis of Hydrogen Peroxide (pages 9192–9198)

      Jennifer K. Edwards and Graham J. Hutchings

      Version of Record online: 16 SEP 2008 | DOI: 10.1002/anie.200802818

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      A great support act at the Palladium: In the search for an alternative to the current indirect industrial synthesis of H2O2, small nanoparticles of Au–Pd alloys have been shown to be highly active catalysts for the direct synthesis of H2O2 from O2 and H2. They do not require the addition of halide and phosphate stabilizers. The active particles comprise mainly Pd (blue, see picture) with some Au (green) supported on carbon (red).

  10. Reviews

    1. Top of page
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    4. Graphical Abstract
    5. Corrigendum
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    8. Obituary
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    10. Minireview
    11. Reviews
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    1. Renewable Resources

      Biofuels and Biomass-To-Liquid Fuels in the Biorefinery: Catalytic Conversion of Lignocellulosic Biomass using Porous Materials (pages 9200–9211)

      Michael Stöcker

      Version of Record online: 20 OCT 2008 | DOI: 10.1002/anie.200801476

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      Wood, a renewable energy source, can be converted into fuels, chemicals, and energy products. An overview is presented of the processing of lignocellulose-rich starting materials into BTL (biomass-to-liquid) fuels, describes the complex reactions that take place at the porous catalysts in a biorefinery, and brings to light the challenges involved in the transition from pilot to production plants.

    2. Catalyst Characteristics

      Molecular Factors of Catalytic Selectivity (pages 9212–9228)

      Gabor A. Somorjai and Jeong Y. Park

      Version of Record online: 12 NOV 2008 | DOI: 10.1002/anie.200803181

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      The magnificent seven: The selectivity of heterogeneous catalyst processes has been defined on the molecular level by seven factors (see picture). These include the structure and the electronic properties of the surface, the type and mobility of the adsorbed species, as well as the charge transport and oxidation states of the catalyst.

  11. Communications

    1. Top of page
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    3. Inside Cover
    4. Graphical Abstract
    5. Corrigendum
    6. News
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    8. Obituary
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    10. Minireview
    11. Reviews
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    1. Heterogeneous Catalysis

      Cooperative Catalysis of Primary and Tertiary Amines Immobilized on Oxide Surfaces for One-Pot C[BOND]C Bond Forming Reactions (pages 9230–9235)

      Ken Motokura, Mizuki Tada and Yasuhiro Iwasawa

      Version of Record online: 2 SEP 2008 | DOI: 10.1002/anie.200802515

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      D'you know what amine? Primary and tertiary amines are both immobilized on the same silica–alumina surface by silane-coupling reactions. The resultant silica–alumina-supported double-amines are found to exhibit excellent catalysis for 1,3-dinitroalkane synthesis from various aldehydes with nitromethane. A cooperative catalytic mechanism on the solid surface for this efficient synthesis is proposed.

    2. Asymmetric Catalysis

      Organocatalytic Asymmetric Diels–Alder Reactions of 3-Vinylindoles (pages 9236–9239)

      Claudio Gioia, Agnès Hauville, Luca Bernardi, Francesco Fini and Alfredo Ricci

      Version of Record online: 29 OCT 2008 | DOI: 10.1002/anie.200804275

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      Diels or no Diels? A bifunctional organic catalyst based on the thiourea motif is able to coordinate both diene and dienophile in an unprecedented asymmetric Diels–Alder reaction of 3-vinylindole derivatives, giving a rapid access to optically active tetra- and hexahydrocarbazoles with excellent results in terms of yields, diastereoselectivities, and enantioselectivities.

    3. Heterogeneous Catalysis

      Heterogeneous Enantioselective Hydrogenation of Aromatic Ketones Catalyzed by Cinchona- and Phosphine-Modified Iridium Catalysts (pages 9240–9244)

      He-yan Jiang, Chao-fen Yang, Chun Li, Hai-yan Fu, Hua Chen, Rui-xiang Li and Xian-jun Li

      Version of Record online: 8 AUG 2008 | DOI: 10.1002/anie.200801809

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      Catalyst support: The first highly enantioselective heterogeneous hydrogenation of aromatic ketones catalyzed by Ir/SiO2 stabilized with Ph3P and modified by a chiral diamine derived from a cinchona alkaloid is described (see scheme). The reaction can be employed for the reduction of a broad range of aromatic ketones to the corresponding alcohols with high enantioselectivity.

    4. Cluster Formation

      Real-Time Characterization of Formation and Breakup of Iridium Clusters in Highly Dealuminated Zeolite Y (pages 9245–9248)

      Alper Uzun and Bruce C. Gates

      Version of Record online: 8 AUG 2008 | DOI: 10.1002/anie.200802140

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      The chemistry of formation of iridium clusters from mononuclear iridium diethylene complexes anchored in dealuminated Y zeolite, and their subsequent breakup—all including changes in the metal–metal, metal–support, and metal–ligand interactions—is demonstrated by time-resolved EXAFS, XANES, and IR spectroscopy.

    5. Amide Synthesis

      Heterogeneously Catalyzed Efficient Oxygenation of Primary Amines to Amides by a Supported Ruthenium Hydroxide Catalyst (pages 9249–9251)

      Jung Won Kim, Kazuya Yamaguchi and Noritaka Mizuno

      Version of Record online: 18 JUL 2008 | DOI: 10.1002/anie.200802464

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      Supporting green chemistry: The supported ruthenium hydroxide Ru(OH)x/Al2O3 acts as an efficient heterogeneous catalyst for the oxygenation of primary amines to primary amides (see scheme). Various primary amines (including aromatic, aliphatic, and heterocyclic) are converted in aqueous media, using air as the sole oxidant and producing only water as a by-product.

    6. Heterogeneous Catalysis

      Photoinduced Reversible Structural Transformation and Selective Oxidation Catalysis of Unsaturated Ruthenium Complexes Supported on SiO2 (pages 9252–9255)

      Mizuki Tada, Yusaku Akatsuka, Yong Yang, Takehiko Sasaki, Mutsuo Kinoshita, Ken Motokura and Yasuhiro Iwasawa

      Version of Record online: 22 OCT 2008 | DOI: 10.1002/anie.200803122

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      Ru experienced? Two novel coordinatively unsaturated SiO2-supported Ru complexes were prepared by photoinduced ligand elimination, accompanied by dissociative coordination of a surface OH group to the unsaturated Ru center by photoirradiation. Wavelength- and atmosphere-dependent photoinduced reversible interconversion occurs between the two Ru complexes. One of the complexes is catalytically active for the photooxidation of cycloalkanes with O2.

    7. Space- and Time-Resolved Combined DRIFT and Raman Spectroscopy: Monitoring Dynamic Surface and Bulk Processes during NOx Storage Reduction (pages 9256–9259)

      Atsushi Urakawa, Nobutaka Maeda and Alfons Baiker

      Version of Record online: 30 OCT 2008 | DOI: 10.1002/anie.200804077

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      What, where, when: A combination of both surface-sensitive (diffuse reflectance infrared Fourier transform spectroscopy, DRIFTS) and bulk-sensitive (Raman spectroscopy) detection at different catalyst-bed positions is shown to be a powerful tool to facilitate deeper understanding of complex dynamic surface and bulk processes, which occur widely in heterogeneous catalysis.

    8. CO Oxidation

      Generating Highly Active Partially Oxidized Platinum during Oxidation of Carbon Monoxide over Pt/Al2O3: In Situ, Time-Resolved, and High-Energy-Resolution X-Ray Absorption Spectroscopy (pages 9260–9264)

      Jagdeep Singh, Evalyn M. C. Alayon, Moniek Tromp, Olga V. Safonova, Pieter Glatzel, Maarten Nachtegaal, Ronald Frahm and Jeroen A. van Bokhoven

      Version of Record online: 29 OCT 2008 | DOI: 10.1002/anie.200803427

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      High activity is generated by sudden formation of disordered oxidic platinum over a platinum catalyst supported on alumina (see picture). High temperature and low concentration of carbon monoxide are required to generate high activity.

    9. Gold Nanoparticles

      Influence of the Support and the Size of Gold Clusters on Catalytic Activity for Glucose Oxidation (pages 9265–9268)

      Tamao Ishida, Naoto Kinoshita, Hiroko Okatsu, Tomoki Akita, Takashi Takei and Masatake Haruta

      Version of Record online: 10 OCT 2008 | DOI: 10.1002/anie.200802845

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      Not all that glitters… The activity of supported gold nanoparticles depends on the method used for their preparation. Gold clusters of about 2 nm in diameter were deposited on nonreducible metal oxides and carbon materials by solid grinding of a volatile organogold complex in a ball mill and subsequent calcination (see scheme). Au/ZrO2 and Au/Al2O3 prepared in this way were extremely efficient catalysts for the aerobic oxidation of glucose.

    10. Redox Chemistry

      Structure and Redox Activity of Copper Sites Isolated in a Nanoporous P4VP Polymeric Matrix (pages 9269–9273)

      Elena Groppo, Mohammed Jasim Uddin, Silvia Bordiga, Adriano Zecchina and Carlo Lamberti

      Version of Record online: 16 SEP 2008 | DOI: 10.1002/anie.200802815

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      A flexible friend: The electronic and structural changes undergone by Cu sites grafted inside an amorphous nanoporous P4VP matrix during a simple redox process (representing more complex liquid-phase catalysis) were investigated by complementary in situ techniques (FTIR, UV/Vis, XAS spectroscopy) (see scheme; brown Cu, green Cl, blue N, red O). The flexibility of the polymeric structure was found to be the key factor in the reversibility of the redox process.

    11. Heterogeneous Catalysis

      Understanding Palladium Hydrogenation Catalysts: When the Nature of the Reactive Molecule Controls the Nature of the Catalyst Active Phase (pages 9274–9278)

      Detre Teschner, Zsolt Révay, János Borsodi, Michael Hävecker, Axel Knop-Gericke, Robert Schlögl, David Milroy, S. David Jackson, Daniel Torres and Philippe Sautet

      Version of Record online: 13 AUG 2008 | DOI: 10.1002/anie.200802134

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      Alkynes of everything: Fundamental differences in the palladium-catalyzed hydrogenation of double and triple C[BOND]C bonds arise from marked differences in the composition of the catalyst surface. In situ X-ray photoelectron spectroscopy of the near-surface region of active palladium catalysts uncovers strong links between the chemical nature of the (alkyne/alkene) reactive molecules and the subsurface state of the catalyst (IIV).

    12. Polymerization Catalysis

      Formation of Nanotubular Methylaluminoxanes and the Nature of the Active Species in Single-Site α-Olefin Polymerization Catalysis (pages 9279–9283)

      Mikko Linnolahti, John R. Severn and Tapani A. Pakkanen

      Version of Record online: 29 AUG 2008 | DOI: 10.1002/anie.200802558

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      Tubular Al's: Quantum chemical calculations show the facile formation of nanotubular methylaluminoxanes from reactions between water and trimethylaluminum. The nanotubular methylaluminoxane is shown to be capable of activating metallocene catalysts for α-olefin polymerization (see structure; red O, bronze Al, blue Zr).

    13. Bimetallic Catalysis

      Enantioselective Bimetallic Catalysis of Michael Additions Forming Quaternary Stereocenters (pages 9284–9288)

      Sascha Jautze and René Peters

      Version of Record online: 27 OCT 2008 | DOI: 10.1002/anie.200803539

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      Robotlike: Low catalyst loadings of a planar-chiral ferrocenyl bispalladacycle are sufficient to catalyze the Michael addition of trisubstituted α-cyanoacetates to enones with excellent yields (TONs up to 2450) and high enantioselectivity. The reaction proceeds by a cooperative bimetallic mechanism and is superior to previous methods relying on soft Lewis acid catalysts.

    14. Heterogeneous Catalysis

      Influence of Carbon Deposition on the Hydrogen Distribution in Pd Nanoparticles and Their Reactivity in Olefin Hydrogenation (pages 9289–9293)

      Markus Wilde, Katsuyuki Fukutani, Wiebke Ludwig, Björn Brandt, Jan-Henrik Fischer, Swetlana Schauermann and Hans-Joachim Freund

      Version of Record online: 16 SEP 2008 | DOI: 10.1002/anie.200801923

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      The mechanism of olefin hydrogenation on a supported noble-metal catalyst requires the presence of weakly bound hydrogen atoms absorbed in the volume of the metal particle (see picture). Co-adsorbed carbonaceous deposits affect the hydrogen distribution in the metal clusters and critically control their activity and selectivity in olefin conversions.

    15. Asymmetric Catalysis

      Enantioselective C[BOND]C Bond Activation of Allenyl Cyclobutanes: Access to Cyclohexenones with Quaternary Stereogenic Centers (pages 9294–9297)

      Tobias Seiser and Nicolai Cramer

      Version of Record online: 29 OCT 2008 | DOI: 10.1002/anie.200804281

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      Chiral rhodium(I) complexes activate allenyl tert-cyclobutanols efficiently through enantioselective insertion into a C[BOND]C σ bond of the cyclobutane (see scheme; cod=1,5-cyclooctadiene, DTBM=3,5-di-tert-butyl-4-methoxyphenyl). Ring expansion by this method produced cyclohexenones with quaternary stereogenic centers with excellent enantioselectivity. The catalyst loading can be decreased to just 0.1 mol % in rhodium.

    16. Surface Chemistry

      On the Role of Surface Modifications of Palladium Catalysts in the Selective Hydrogenation of Acetylene (pages 9299–9302)

      Felix Studt, Frank Abild-Pedersen, Thomas Bligaard, Rasmus Z. Sørensen, Claus H. Christensen and Jens K. Nørskov

      Version of Record online: 2 OCT 2008 | DOI: 10.1002/anie.200802844

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      Summing Me up: DFT calculations have shown that alloying, subsurface carbon, and hydride formation, all increase the selectivity of Pd catalysts for acetylene hydrogenation by weakening the surface–adsorbate bond. A simple descriptor—the adsorption energy of a methyl group—has been used to quantify and compare the different effects in the adsorption of acetylene and ethylene on various transition-metal surfaces (see picture).

    17. Heterogeneous Catalysis

      In Situ Redispersion of Platinum Autoexhaust Catalysts: An On-Line Approach to Increasing Catalyst Lifetimes? (pages 9303–9306)

      Yasutaka Nagai, Kazuhiko Dohmae, Yasuo Ikeda, Nobuyuki Takagi, Toshitaka Tanabe, Naoyuki Hara, Gemma Guilera, Sakura Pascarelli, Mark A. Newton, Oji Kuno, Hongying Jiang, Hirofumi Shinjoh and Shin'ichi Matsumoto

      Version of Record online: 10 OCT 2008 | DOI: 10.1002/anie.200803126

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      Dynamic observation: The rapid oxidative redispersion of large Pt nanoparticles supported on ceria-based oxide in autoexhaust catalysts is demonstrated in the absence of Cl by in situ XANES analysis. An atomic migration model accounts for the observed redispersion through the trapping of Pt species at sites on the Ce support that exhibit strong interactions between the Pt oxide and the support.

    18. Electrochemistry

      Promotional Effect of Palladium on the Hydrogen Oxidation Reaction at a PtPd Alloy Electrode (pages 9307–9310)

      Sung Jong Yoo, Hee-Young Park, Tae-Yeol Jeon, In-Su Park, Yong-Hun Cho and Yung-Eun Sung

      Version of Record online: 29 OCT 2008 | DOI: 10.1002/anie.200802749

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      A volcano curve is observed for the hydrogen oxidation reaction (HOR) as a function of the Pd content of alloyed PtPd electrodes. The maximum exchange current density was obtained for Pt72Pd28, and the results indicate that PdHx species (hydrogen gas spontaneously adsorbed to Pd; see picture) causes the electronic structure of Pt to be favorable for the HOR.

    19. Reactive Polyolefins

      Polyethylene Building Blocks by Catalyzed Chain Growth and Efficient End Functionalization Strategies, Including Click Chemistry (pages 9311–9313)

      Rémi Briquel, Jérôme Mazzolini, Tristana Le Bris, Olivier Boyron, Fernande Boisson, Frédéric Delolme, Franck D'Agosto, Christophe Boisson and Roger Spitz

      Version of Record online: 29 OCT 2008 | DOI: 10.1002/anie.200804445

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      A means to an end: Polyethylene chains obtained by catalyzed chain growth on magnesium and exhibiting molar masses up to 5000 g mol−1 have been end-functionalized in high yield with iodide, azide, and amine reactive end groups (see scheme). The functionalized polyethylenes can be used to generate a range of reactive polyolefins; for example, the azide-functionalized chain can undergo “click” reactions to afford macromonomers.

    20. Reforming Catalysts

      Effect of Thermal Treatment on Activity and Durability of CuFe2O4–Al2O3 Composite Catalysts for Steam Reforming of Dimethyl Ether (pages 9314–9317)

      Kajornsak Faungnawakij, Ryuji Kikuchi, Naohiro Shimoda, Tetsuya Fukunaga and Koichi Eguchi

      Version of Record online: 31 OCT 2008 | DOI: 10.1002/anie.200802809

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      A simple thermal treatment remarkably enhances the activity and durability of CuFe2O4–Al2O3 composite catalysts in reforming dimethyl ether for hydrogen production. The most effective treatment temperature range is 700 to 800 °C. The active phase, CuFe1.5Al0.5O4 formed through a solid-state reaction between CuFe2O4 and Al2O3, and the original phase, CuFe2O4, contribute synergistically to the enhancement.

    21. Cycloaddition

      Rhenium-Catalyzed Synthesis of Stereodefined Cyclopentenes from β-Ketoesters and Aliphatic Allenes (pages 9318–9321)

      Salprima Yudha S., Yoichiro Kuninobu and Kazuhiko Takai

      Version of Record online: 7 NOV 2008 | DOI: 10.1002/anie.200803350

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      Come on allene: Commercially available [Re2(CO)10] as a catalyst provides five-membered carbocycles in moderate to excellent yields with high stereoselectivity (see scheme). The configuration at each of the three sp3 carbon centers of the ring is defined. The reaction proceeds at the β, γ, and adjacent methylene positions of the allene; previously, similar reactions usually occurred at the α, β, and γ positions of the allene.

    22. Enzyme Mechanisms

      Thioester Hydrolysis and C[BOND]C Bond Formation by Carboxymethylproline Synthase from the Crotonase Superfamily (pages 9322–9325)

      Edward T. Batchelar, Refaat B. Hamed, Christian Ducho, Timothy D. W. Claridge, Mariola J. Edelmann, Benedikt Kessler and Christopher J. Schofield

      Version of Record online: 29 OCT 2008 | DOI: 10.1002/anie.200803906

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      Enzyme in action: Labeling studies and the finding that carboxymethylproline synthase catalyzes production of deuterated (2S,5S)-6,6′-dimethyl-trans-carboxymethylproline (3) from dimethylmalonyl-CoA (1) and labeled l-pyrroline-5-carboxylate (2) limit possible mechanisms of C[BOND]C bond formation and thioester hydrolysis. A key feature in the catalysis is that intermediates are stabilized by hydrogen bonds in the “oxy-anion hole” of the enzyme (dark curve in scheme).

    23. N-Heterocyclic Carbenes

      Chiral Palladium(II) Complexes Possessing a Tridentate N-Heterocyclic Carbene Amidate Alkoxide Ligand: Access to Oxygen-Bridging Dimer Structures (pages 9326–9329)

      Satoshi Sakaguchi, Kyung Soo Yoo, Justin O'Neill, Joo Ho Lee, Timothy Stewart and Kyung Woon Jung

      Version of Record online: 29 OCT 2008 | DOI: 10.1002/anie.200803793

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      Catalysts with a bite: Chiral PdII complexes were prepared with tridentate N-heterocyclic carbene amidate alkoxide ligands. Dimeric and monomeric forms were mutually convertible by acid or base treatment (see scheme). The catalysts promote asymmetric Heck reactions efficiently, offering high enantioselectivities far superior to those of existing methods.

    24. Radical Reactions

      Efficient Aerobic Oxidative Synthesis of 2-Substituted Benzoxazoles, Benzothiazoles, and Benzimidazoles Catalyzed by 4-Methoxy-TEMPO (pages 9330–9333)

      Yong-Xing Chen, Ling-Feng Qian, Wei Zhang and Bing Han

      Version of Record online: 29 OCT 2008 | DOI: 10.1002/anie.200803381

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      Setting the TEMPO: The scheme shows the efficient aerobic synthesis of 2-substituted benzoxazoles, benzothiazoles, and benzimidazoles where 4-methoxy-2,2,6,6-tetramethyl-1-piperidinyloxy free radical (4-Methoxy-TEMPO) is used as the catalyst.

    25. Homogeneous Catalysis

      Nickel-Catalyzed Negishi Cross-Couplings of Secondary Nucleophiles with Secondary Propargylic Electrophiles at Room Temperature (pages 9334–9336)

      Sean W. Smith and Gregory C. Fu

      Version of Record online: 29 OCT 2008 | DOI: 10.1002/anie.200802784

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      Mild thing: The first nickel-based catalysts for cross-couplings of secondary organometallic nucleophiles with secondary alkyl electrophiles have been developed. Thus, Negishi reactions proceed under mild conditions (at room temperature with no basic activators) in the presence of NiCl2⋅glyme and a tridentate ligand (see scheme).

    26. Chiral Amines

      Formal Asymmetric Biocatalytic Reductive Amination (pages 9337–9340)

      Dominik Koszelewski, Iván Lavandera, Dorina Clay, Georg M. Guebitz, David Rozzell and Wolfgang Kroutil

      Version of Record online: 29 OCT 2008 | DOI: 10.1002/anie.200803763

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      All for one: A combination of three biocatalysts (ω-transaminase, alanine dehydrogenase, and an enzyme such as formate dehydrogenase for cofactor recycling) catalyze a cascade to achieve the asymmetric transformation of a ketone into a primary α-chiral unprotected amine through a formal stereoselective reductive amination (see scheme). Only ammonia and the reducing agent (formate) are consumed during this reaction.

    27. Hydrogen Production

      Simultaneous Production of Hydrogen and Synthesis Gas by Combining Water Splitting with Partial Oxidation of Methane in a Hollow-Fiber Membrane Reactor (pages 9341–9344)

      Heqing Jiang, Haihui Wang, Steffen Werth, Thomas Schiestel and Jürgen Caro

      Version of Record online: 23 OCT 2008 | DOI: 10.1002/anie.200803899

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      Splitting water: Oxygen-permeable perovskite hollow-fiber membranes are used to produce hydrogen and synthesis gas from water and methane (see picture). The process yields valuable compounds, and provides insight into the interplay of catalysis and separation in a membrane reactor.

    28. Biofuels

      Efficient Catalytic System for the Selective Production of 5-Hydroxymethylfurfural from Glucose and Fructose (pages 9345–9348)

      Gen Yong, Yugen Zhang and Jackie Y. Ying

      Version of Record online: 27 OCT 2008 | DOI: 10.1002/anie.200803207

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      A sweet conversion! A NHC–Cr/ionic liquid system has achieved excellent efficiency and the highest 5-hydroxymethylfurfural (1; see scheme; NHC=N-heterocyclic carbene) yields reported thus far for both fructose and glucose feedstocks. The catalyst and ionic liquid are tolerant of high substrate loading and can be recycled after extraction of the product.

    29. Nanotechnology

      Ultrafast Catalytic Alloy Nanomotors (pages 9349–9351)

      U. Korcan Demirok, Rawiwan Laocharoensuk, Kalayil Manian Manesh and Joseph Wang

      Version of Record online: 29 OCT 2008 | DOI: 10.1002/anie.200803841

      Thumbnail image of graphical abstract

      Turbo nanomotors: A dramatic increase of the speed of fuel-driven nanowire motors is obtained using an Ag/Au alloy segment. These nanomotors offer speeds as high as 150 μm s−1 (75 body lengths per second), approaching those of the most efficient biomotors. The increase in the fuel decomposition rate associated with the electrochemical reactivity of Ag/Au alloys will enable the design of energy-efficient nanomotors.

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