Angewandte Chemie International Edition

Cover image for Vol. 47 Issue 46

November 3, 2008

Volume 47, Issue 46

Pages 8751–8967

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Obituary
    7. Book Review
    8. Highlights
    9. Minireview
    10. Review
    11. Communications
    12. Preview
    1. Cover Picture: Cryo Electron Tomography Reveals Confined Complex Morphologies of Tripeptide-Containing Amphiphilic Double-Comb Diblock Copolymers (Angew. Chem. Int. Ed. 46/2008) (page 8751)

      Alison L. Parry, Paul H. H. Bomans, Simon J. Holder, Nico A. J. M. Sommerdijk and Stefano C. G. Biagini

      Article first published online: 29 OCT 2008 | DOI: 10.1002/anie.200890233

      Thumbnail image of graphical abstract

      The anatomy of a copolymer is presented by N. A. J. M. Sommerdijk et al. in their Communication on page 8859 ff. The amphiphilic double-comb diblock polymer with oligo(ethylene oxide) and peptide chains aggregates to form complex shapes in aqueous solution. From cryo electron tomograms, 3D volumes were reconstructed (shown as a set of slices). Further visualization highlights branches and loops in a folded wormlike micelle (purple) and the channel structure inside a bicontinuous morphology (yellow).

  2. Inside Cover

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Obituary
    7. Book Review
    8. Highlights
    9. Minireview
    10. Review
    11. Communications
    12. Preview
    1. Inside Cover: Ordering and Stabilization of Metal–Organic Coordination Chains by Hierarchical Assembly through Hydrogen Bonding at a Surface (Angew. Chem. Int. Ed. 46/2008) (page 8752)

      Alexander Langner, Steven L. Tait, Nian Lin, Rajadurai Chandrasekar, Mario Ruben and Klaus Kern

      Article first published online: 29 OCT 2008 | DOI: 10.1002/anie.200890234

      Thumbnail image of graphical abstract

      Selective interactions impose a structural hierarchy during self-assembly and are key for rational tailoring of the supramolecular architecture, according to S. L. Tait, and co-workers in their Communication on page 8835 ff. A labile 1D copper-bipyridine coordination system (blue in the STM topographs) is stabilized and ordered through cooperative assembly with terephthalic acid (red) to produce well-ordered self-assembled nanostructures.

  3. Graphical Abstract

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Obituary
    7. Book Review
    8. Highlights
    9. Minireview
    10. Review
    11. Communications
    12. Preview
    1. Graphical Abstract: Angew. Chem. Int. Ed. 46/2008 (pages 8755–8766)

      Article first published online: 29 OCT 2008 | DOI: 10.1002/anie.200890235

  4. News

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Obituary
    7. Book Review
    8. Highlights
    9. Minireview
    10. Review
    11. Communications
    12. Preview
  5. Obituary

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Obituary
    7. Book Review
    8. Highlights
    9. Minireview
    10. Review
    11. Communications
    12. Preview
    1. Jeremy R. Knowles (1935–2008) (pages 8772–8773)

      E. J. Corey and Neil L. Rudenstine

      Article first published online: 29 OCT 2008 | DOI: 10.1002/anie.200804809

  6. Book Review

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Obituary
    7. Book Review
    8. Highlights
    9. Minireview
    10. Review
    11. Communications
    12. Preview
  7. Highlights

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Obituary
    7. Book Review
    8. Highlights
    9. Minireview
    10. Review
    11. Communications
    12. Preview
    1. Nanocomposites

      Cool as a Cucumber (pages 8776–8777)

      Stephen L. Craig

      Article first published online: 29 SEP 2008 | DOI: 10.1002/anie.200802334

      Thumbnail image of graphical abstract

      An inspired design: A new class of nanocomposites can reversibly switch its mechanical stiffness by up to three orders of magnitude in response to its environment. The architecture of the material is inspired by the dermis of the sea cucumber (see pictures), and the mechanically adaptable composites are potentially suitable for use in biomedical applications.

    2. Metastable Compounds

      Opening the “Stable” Door (pages 8778–8780)

      Matthew J. Rosseinsky

      Article first published online: 29 SEP 2008 | DOI: 10.1002/anie.200802365

      Thumbnail image of graphical abstract

      When the energy landscape offers numerous low-energy structures, the synthetic method can determine which structure is formed. In solid-state reactions yielding new crystalline extended structures from solid precursor phases, mass transport coupled with pronounced reorganization of atomic coordination environments is required. The picture shows the reaction of BaO (left) with TiO2 (right) to form BaTiO3 (middle).

  8. Minireview

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Obituary
    7. Book Review
    8. Highlights
    9. Minireview
    10. Review
    11. Communications
    12. Preview
    1. Enzyme Catalysis

      Enantiocomplementary Enzymes: Classification, Molecular Basis for Their Enantiopreference, and Prospects for Mirror-Image Biotransformations (pages 8782–8793)

      Paul F. Mugford, Ulrike G. Wagner, Yun Jiang, Kurt Faber and Romas J. Kazlauskas

      Article first published online: 10 OCT 2008 | DOI: 10.1002/anie.200705159

      Thumbnail image of graphical abstract

      Enzyme pairs that catalyze the same reaction but favor opposite enantiomers are known as enantiocomplementary enzymes (see scheme). To create mirror-image active sites, nature can switch the locations of binding sites and/or the locations of key catalytic groups. In this Minireview, X-ray crystal structures of enantiocomplementary enzymes are surveyed and classified into four groups.

  9. Review

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Obituary
    7. Book Review
    8. Highlights
    9. Minireview
    10. Review
    11. Communications
    12. Preview
    1. Coordination Chemistry

      Supramolecular Coordination Chemistry: The Synergistic Effect of Serendipity and Rational Design (pages 8794–8824)

      Rolf W. Saalfrank, Harald Maid and Andreas Scheurer

      Article first published online: 20 OCT 2008 | DOI: 10.1002/anie.200702075

      Thumbnail image of graphical abstract

      Luck or ability? In the field of supramolecular coordination chemistry, impressive advances have been achieved by the augmentation of initial serendipitous discoveries with rational design. Detailed consideration of symmetry and of the basic principles of coordination chemistry have led to rational strategies for the construction of diverse nanostructures with specific form and size (for example, 1; Fe: white, tripodal benzene ligand: yellow).

  10. Communications

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Obituary
    7. Book Review
    8. Highlights
    9. Minireview
    10. Review
    11. Communications
    12. Preview
    1. Organic Frameworks

      A Belt-Shaped, Blue Luminescent, and Semiconducting Covalent Organic Framework (pages 8826–8830)

      Shun Wan, Jia Guo, Jangbae Kim, Hyotcherl Ihee and Donglin Jiang

      Article first published online: 1 OCT 2008 | DOI: 10.1002/anie.200803826

      Thumbnail image of graphical abstract

      Blue belt: Condensation polymerization of pyrene (blue) and triphenylene (green) monomers leads to the formation of a hexagonal mesoporous covalent organic framework (see picture). This material exists in a belt shape, absorbs photons over a wide wavelength range to emit them as blue luminescence, and is semiconducting, as well as being capable of repetitive on–off switching.

      Corrected by:

      Corrigendum: A Belt-Shaped, Blue Luminescent, and Semiconducting Covalent Organic Framework

      Vol. 48, Issue 18, 3207, Article first published online: 15 APR 2009

    2. Switchable Polymer Surfaces

      A Switchable Biocompatible Polymer Surface with Self-Sterilizing and Nonfouling Capabilities (pages 8831–8834)

      Gang Cheng, Hong Xue, Zheng Zhang, Shengfu Chen and Shaoyi Jiang

      Article first published online: 8 OCT 2008 | DOI: 10.1002/anie.200803570

      Thumbnail image of graphical abstract

      Trap, kill, and release: An antimicrobial cationic surface can effectively kill bacterial cells and switch to a nonfouling zwitterionic surface which releases dead microorganisms upon hydrolysis (see picture). This biocompatible nonfouling surface can prevent further attachment of proteins and microorganisms and the formation of a biofilm on the surface.

    3. Supramolecular Networks

      Ordering and Stabilization of Metal–Organic Coordination Chains by Hierarchical Assembly through Hydrogen Bonding at a Surface (pages 8835–8838)

      Alexander Langner, Steven L. Tait, Nian Lin, Rajadurai Chandrasekar, Mario Ruben and Klaus Kern

      Article first published online: 4 SEP 2008 | DOI: 10.1002/anie.200803124

      Thumbnail image of graphical abstract

      Supramolecular glue: One-dimensional copper–pyridyl coordination chains on a Cu(100) surface are stabilized and ordered by dicarboxylic ligands through hydrogen-bonding interactions. This hierarchical bonding motif demonstrates a strategy for developing complex, yet well-ordered, supramolecular surface structures by self-assembly, such as these stable islands (see picture) with a one-dimensional coordination character.

    4. DNA Manipulation

      Straightforward and Reversible Photoregulation of Hybridization by Using a Photochromic Nucleoside (pages 8839–8842)

      Shinzi Ogasawara and Mizuo Maeda

      Article first published online: 10 OCT 2008 | DOI: 10.1002/anie.200803496

      Thumbnail image of graphical abstract

      A light switch: A strategy for the photoregulation of hybridization by using the cistrans photoisomerization of a photochromic nucleoside (PCN) is reported. This process enables the switch between duplexes and single strands in an extremely straightforward and reversible manner with light stimulation (see scheme), even at room temperature. Additionally, installation of PCNs into DNA had little influence on the B-form structure when the duplex was formed.

    5. Coordination Polymers

      A Bistable Porous Coordination Polymer with a Bond-Switching Mechanism Showing Reversible Structural and Functional Transformations (pages 8843–8847)

      Sujit K. Ghosh, Wakako Kaneko, Daisuke Kiriya, Masaaki Ohba and Susumu Kitagawa

      Article first published online: 15 OCT 2008 | DOI: 10.1002/anie.200802803

      Thumbnail image of graphical abstract

      Ring the changes: A 2D crystalline coordination polymer 1 is transformed reversibly into a 3D crystal 1 a by dehydration. This reversible structural transformation is accompanied by a change in optical and magnetic properties. The 3D coordination framework absorbs H2O molecules but rejects common organic solvents, such as MeOH, EtOH, THF, and Me2CO.

    6. Single-Molecule Magnets

      Dinuclear Dysprosium(III) Single-Molecule Magnets with a Large Anisotropic Barrier (pages 8848–8851)

      Po-Heng Lin, Tara J. Burchell, Rodolphe Clérac and Muralee Murugesu

      Article first published online: 16 OCT 2008 | DOI: 10.1002/anie.200802966

      Thumbnail image of graphical abstract

      Dysprosium-based single-molecule magnets: Single-molecule magnets (SMMs) of dinuclear dysprosium(III) having thermal and quantum tunneling regimes of magnetization relaxation have been synthesized. Remarkably large energy barriers up to 71 K are observed, in particular for the polymeric complex network, which has the largest energy gap for a lanthanide complex and one of the highest barriers reported for a SMM.

    7. Natural Products

      Enantioselective Synthesis of the Core of Banyaside, Suomilide, and Spumigin HKVV (pages 8852–8855)

      Corinna S. Schindler, Corey R. J. Stephenson and Erick M. Carreira

      Article first published online: 15 OCT 2008 | DOI: 10.1002/anie.200803655

      Thumbnail image of graphical abstract

      Concise: The first synthesis of the unique azabicyclononane core found in the aeruginosin class of serine protease inhibitors is described. The route is characterized by its efficiency (eight steps) and sets the stage for subsequent introduction of the glycosyl and peptidyl side chains that differentiate the members of the aeruginosin family of natural products.

    8. Luminescent Probes

      Intermolecular Sensitization of a Terbium-Containing Amphiphile by an Integral Membrane Protein (pages 8856–8858)

      Catherine L. Davies, Nicholas G. Housden and Anne-K. Duhme-Klair

      Article first published online: 10 OCT 2008 | DOI: 10.1002/anie.200803828

      Thumbnail image of graphical abstract

      A luminescent probe for integral membrane proteins (IMPs): Intermolecular sensitization of Tb luminescence is observed in micelles in which the polar head group of a Tb-containing lipid analogue is located close to an antenna chromophore, such as tryptophan, in a surfactant analogue that mimics interfacially bound tryptophan residues of an IMP or tryptophan in the aromatic collar of the vitamin B12 transporter protein BtuB (see picture).

    9. Copolymer Morphologies

      Cryo Electron Tomography Reveals Confined Complex Morphologies of Tripeptide-Containing Amphiphilic Double-Comb Diblock Copolymers (pages 8859–8862)

      Alison L. Parry, Paul H. H. Bomans, Simon J. Holder, Nico A. J. M. Sommerdijk and Stefano C. G. Biagini

      Article first published online: 11 SEP 2008 | DOI: 10.1002/anie.200802834

      Thumbnail image of graphical abstract

      Sequence sets structure: Amphiphilic norbornene-based double-comb diblock polymers with peptide and oligo(ethylene oxide) side chains aggregate in water to form unprecedented complex morphologies depending on the amino acid sequence of the peptide. The internal structures of the aggregates observed by cryo electron tomography show densely folded and highly branched wormlike micelles (left) and spherical aggregates with a bicontinuous architecture (right).

    10. Phosphorus-Rich Organic Molecules

      A Niobium-Mediated Cycle Producing Phosphorus-Rich Organic Molecules from White Phosphorus (P4) through Activation, Functionalization, and Transfer Reactions (pages 8863–8866)

      Brandi M. Cossairt and Christopher C. Cummins

      Article first published online: 15 OCT 2008 | DOI: 10.1002/anie.200803971

      Thumbnail image of graphical abstract

      PROMs: Niobium-mediated aggregation of two molecules of white phosphorus and subsequent exploitation of niobium–phosphorus multiple bonding leads to the synthesis of phosphorus-rich organic molecules as Diels–Alder adducts (see scheme; orange P, white C).

    11. Peroxo Complexes

      Stepwise Oxygenation of Pinacolborane by a Rhodiumperoxo Complex: Detection of an Intermediate Metal Borate and Perborate (pages 8867–8871)

      Marcel Ahijado Salomon, Thomas Braun and Anna Penner

      Article first published online: 10 OCT 2008 | DOI: 10.1002/anie.200803768

      Thumbnail image of graphical abstract

      Acting as go-between: A rhodium borate and perborate have been identified as intermediates in the rhodium-mediated oxygenation of pinacolborane (HBpin; see scheme). The rhodium(III)–peroxo complex reacts with the Lewis acidic boron compound HBpin by oxygen transfer from the rhodium center to HBpin to give a rhodium(I) species. The reaction sequence might play a crucial role in the homocoupling of boronic acid.

    12. Biosynthesis

      Sequential Asymmetric Polyketide Heterocyclization Catalyzed by a Single Cytochrome P450 Monooxygenase (AurH) (pages 8872–8875)

      Martin E. A. Richter, Nelly Traitcheva, Uwe Knüpfer and Christian Hertweck

      Article first published online: 15 OCT 2008 | DOI: 10.1002/anie.200803714

      Thumbnail image of graphical abstract

      Two in one: In vitro biotransformations with the cytochrome P450 monooxygenase AurH from the aureothin (1) biosynthetic pathway provided direct experimental evidence that a single monooxygenase can install two C[BOND]O bonds sequentially to form a tetrahydrofuran ring. Structural elucidation of the intermediate 2 revealed the order of bond formation and the stereochemical course of this unprecedented oxygenation–heterocyclization reaction.

    13. Subphthalocyanines

      Ethynyl–Boron Subphthalocyanines Displaying Efficient Cascade Energy Transfer and Large Stokes Shifts (pages 8876–8880)

      Franck Camerel, Gilles Ulrich, Pascal Retailleau and Raymond Ziessel

      Article first published online: 9 OCT 2008 | DOI: 10.1002/anie.200803131

      Thumbnail image of graphical abstract

      A new class of luminescent dyes incorporates aromatic residues attached by an ethynyl link to the boron center of a subphthalocyanine (SubPc; see picture). Efficient energy transfer from energy-donor subunits to the SubPc produces very large Stokes shifts, while luminescence quantum yields are maintained. An acid-triggered “switching on” of SubPc emission occurs when a dibutylamino fragment is axially coordinated to the SubPc.

    14. 1,3-Dipolar Cycloaddition

      [(NHC)2Cu]X Complexes as Efficient Catalysts for Azide–Alkyne Click Chemistry at Low Catalyst Loadings (pages 8881–8884)

      Silvia Díez-González and Steven P. Nolan

      Article first published online: 10 OCT 2008 | DOI: 10.1002/anie.200803289

      Thumbnail image of graphical abstract

      La click, c'est chic! A catalytic system based on an [(NHC)2Cu]X complex (NHC=N-heterocyclic carbene) was developed for the [3+2] cycloaddition of azides with alkynes under click conditions (see scheme). This system is broad in scope and highly efficient (turnover frequencies up to 5000 h−1) even at very low catalyst loadings (down to 40 ppm). Preliminary mechanistic studies suggest a specific precatalyst-activation pathway.

    15. Diels–Alder Reactions

      Stable 5-Substituted Cyclopentadienes for the Diels–Alder Cycloaddition and their Application to the Synthesis of Palau'amine (pages 8885–8888)

      Jonathan Hudon, Timothy A. Cernak, James A. Ashenhurst and James L. Gleason

      Article first published online: 15 OCT 2008 | DOI: 10.1002/anie.200803344

      Thumbnail image of graphical abstract

      Putting the brakes on a hydride shift: The incorporation of a 2-silyloxy group increases both the stability and reactivity of 5-substituted cyclopentadienes, thus facilitating their preparation and use (see scheme; Bz=benzyl, TBS=tert-butyldimethylsilyl). This approach has been applied to the synthesis of the E ring in the marine alkaloid palau'amine.

    16. Enzyme-Catalyzed Glycosylation

      Probing the Aglycon Promiscuity of an Engineered Glycosyltransferase (pages 8889–8892)

      Richard W. Gantt, Randal D. Goff, Gavin J. Williams and Jon S. Thorson

      Article first published online: 16 OCT 2008 | DOI: 10.1002/anie.200803508

      Thumbnail image of graphical abstract

      A sweet library: Two variants (wild-type (WT) and a triple mutant) of glycosyltransferase (GT) OleD have been shown to catalyze glycosylation of over 70 substrates, formation of O-, S- and N-glycosidic bonds, and iterative glycosylation (see scheme). Identified substrates include nucleophiles not previously known to act in GT reactions and span numerous natural product and therapeutic drug classes.

    17. Heterogeneous Catalysis

      A Reactive Oxide Overlayer on Rhodium Nanoparticles during CO Oxidation and Its Size Dependence Studied by In Situ Ambient-Pressure X-ray Photoelectron Spectroscopy (pages 8893–8896)

      Michael E. Grass, Yawen Zhang, Derek R. Butcher, Jeong Y. Park, Yimin Li, Hendrik Bluhm, Kaitlin M. Bratlie, Tianfu Zhang and Gabor A. Somorjai

      Article first published online: 16 OCT 2008 | DOI: 10.1002/anie.200803574

      Thumbnail image of graphical abstract

      The smaller, the better: In situ synchrotron ambient pressure X-ray photoelectron spectroscopy allows examination of the oxidation state of the surface of the rhodium nanoparticles (NPs) during CO oxidation in an O2 atmosphere. 2 nm NPs oxidize to a larger extent than 7 nm NPs during reaction at 150–200 °C, which correlates with a fivefold increase in turnover frequency for the smaller nanoparticles.

    18. Synthetic Methods

      Iron-Mediated Direct Arylation of Unactivated Arenes (pages 8897–8900)

      Jun Wen, Ji Zhang, Shan-Yong Chen, Jing Li and Xiao-Qi Yu

      Article first published online: 7 OCT 2008 | DOI: 10.1002/anie.200802526

      Thumbnail image of graphical abstract

      Inexpensive and straightforward: An iron-mediated cross-coupling reaction generates biaryl compounds through C[BOND]H bond activation, using easily handled reagents with low toxicity. Under the optimized reaction conditions a series of substituted phenylboronic acids were coupled with several simple unactivated arenes.

    19. Nanostructures

      Synthesis of Trisoctahedral Gold Nanocrystals with Exposed High-Index Facets by a Facile Chemical Method (pages 8901–8904)

      Yanyun Ma, Qin Kuang, Zhiyuan Jiang, Zhaoxiong Xie, Rongbin Huang and Lansun Zheng

      Article first published online: 7 OCT 2008 | DOI: 10.1002/anie.200802750

      Thumbnail image of graphical abstract

      The many faces of gold: Trisoctahedral gold nanocrystals have been synthesized in a high yield for the first time. Electron diffraction and electron microscopy demonstrate that the nanocrystals are enclosed by 24 high-index facets, such as {221} planes (see SEM image (left) and model (right)).

    20. Nanonets

      Controllable Nanonet Assembly Utilizing a Pressure-Difference Method Based on Anodic Aluminum Oxide Templates (pages 8905–8908)

      Zhixun Luo, Yuanyuan Liu, Longtian Kang, Yaobing Wang, Hongbing Fu, Ying Ma, Jiannian Yao and Boon H. Loo

      Article first published online: 10 OCT 2008 | DOI: 10.1002/anie.200802788

      Thumbnail image of graphical abstract

      A large network with a nanonet architecture has been fabricated from tetrakis(p-chlorophenyl)porphyrin by a pressure differential across films deposited on a template. The pinhole migration mechanism of the nanonet assembly is based on controllable dynamic balance.

    21. Synthetic Methods

      A Stereospecific Palladium-Catalyzed Route to Monoalkyl Diazenes for Mild Allylic Reduction (pages 8909–8912)

      Mohammad Movassaghi and Omar K. Ahmad

      Article first published online: 16 OCT 2008 | DOI: 10.1002/anie.200802921

      Thumbnail image of graphical abstract

      One step beyond: The first single-step stereospecific transition-metal-catalyzed conversion of allylic electrophiles into monoalkyl diazenes is described. This synthesis of allylic monoalkyl diazenes offers a new strategy for asymmetric synthesis by the reduction of optically active substrates or the use of chiral catalyst systems. Sensitive substrates are reduced in a highly selective manner. Ar=2-NO2C6H4.

    22. Porphyrinoids

      Doubly N-Fused Porphyrin (pages 8913–8916)

      Motoki Toganoh, Tomoyuki Kimura, Hidemitsu Uno and Hiroyuki Furuta

      Article first published online: 10 OCT 2008 | DOI: 10.1002/anie.200803670

      Thumbnail image of graphical abstract

      Are you N-fused? Doubly N-fused porphyrin (see picture; Br red, F green, N blue) exhibits exceptionally long-wavelength absorption for an 18π aromatic system (in excess of 1600 nm). The HOMO–LUMO energy gap of doubly N-fused porphyrin is extremely small for an [18]annulenic compound and results from endocyclic extension of the porphyrin π system.

    23. Carbohydrates

      Sequential Norrish Type II Photoelimination and Intramolecular Aldol Cyclization of 1,2-Diketones in Carbohydrate Systems: Stereoselective Synthesis of Cyclopentitols (pages 8917–8919)

      Dimitri Álvarez-Dorta, Elisa I. León, Alan R. Kennedy, Concepción Riesco-Fagundo and Ernesto Suárez

      Article first published online: 9 OCT 2008 | DOI: 10.1002/anie.200803696

      Thumbnail image of graphical abstract

      Opened and closed: Visible-light photostimulation of 2,3-diuloses I triggers an unprecedented sequential rearrangement: A Norrish type II photoelimination to give an isolable acyclic photoenol intermediate II is followed by an intramolecular enolexo aldolization. The contraction of the pyranose ring in this process leads to a new type of cyclopentitol derivative III. R=acyl, alkyl, silyl group.

    24. Asymmetric Synthesis

      Highly Enantioselective Synthesis of Optically Active Ketones by Iridium-Catalyzed Asymmetric Hydrogenation (pages 8920–8923)

      Sheng-Mei Lu and Carsten Bolm

      Article first published online: 15 OCT 2008 | DOI: 10.1002/anie.200803709

      Thumbnail image of graphical abstract

      Close to perfect enantioselectivity (up to 99 % ee, see scheme) is found for the formation of α-substituted ketones by the asymmetric hydrogenation of enones with an iridium–phosphinooxazoline catalyst. In an operationally simple process, both linear and cyclic substrates react well and afford the desired products in high yields. A wide variety of substituents are tolerated, thus making the method synthetically appealing.

    25. Nanocomposite Catalysts

      Core–Satellite Nanocomposite Catalysts Protected by a Porous Silica Shell: Controllable Reactivity, High Stability, and Magnetic Recyclability (pages 8924–8928)

      Jianping Ge, Qiao Zhang, Tierui Zhang and Yadong Yin

      Article first published online: 16 OCT 2008 | DOI: 10.1002/anie.200803968

      Thumbnail image of graphical abstract

      Limited holeliness: Core–satellite nanocomposite catalysts protected by a layer of mesoporous silica have been fabricated through the combination of simple sol–gel and etching processes. As superparamagnetic components are also incorporated, these composite structures are ideal recyclable catalysts. (see plot for performance in repeated cycles of 4-nitrophenol reduction).

    26. Metal–Organic Frameworks

      Negative Thermal Expansion in the Metal–Organic Framework Material Cu3(1,3,5-benzenetricarboxylate)2 (pages 8929–8932)

      Yue Wu, Atsushi Kobayashi, Gregory J. Halder, Vanessa K. Peterson, Karena W. Chapman, Nina Lock, Peter D. Southon and Cameron J. Kepert

      Article first published online: 10 OCT 2008 | DOI: 10.1002/anie.200803925

      Thumbnail image of graphical abstract

      The action behind contraction: The metal–organic framework [Cu3(btc)2] displays negative thermal expansion (NTE) over a broad temperature range. This property arises from two coincident mechanisms, each of which are unique for NTE systems: the concerted transverse vibration of triangular organic linkers, and the local dynamic distortion of dinuclear metal centers within the framework lattice.

    27. Ring Expansion

      Synthesis of Cyclobutenes by Highly Selective Transition-Metal-Catalyzed Ring Expansion of Cyclopropanes (pages 8933–8936)

      Huadong Xu, Wen Zhang, Dongxu Shu, Jenny B. Werness and Weiping Tang

      Article first published online: 10 OCT 2008 | DOI: 10.1002/anie.200803910

      Thumbnail image of graphical abstract

      A highly chemoselective, regioselective, and stereospecific synthesis of polysubstituted cyclobutenes, by catalyst-controlled ring expansion of cyclopropanes via metal carbene intermediates, is reported. Transition-metal catalysts showed profound effects on the reactivity and selectivity of metal carbene intermediates in this ring-expansion reaction.

    28. Gold Hydride Complexes

      Reactions of a Stable Monomeric Gold(I) Hydride Complex (pages 8937–8940)

      Emily Y. Tsui, Peter Müller and Joseph P. Sadighi

      Article first published online: 15 OCT 2008 | DOI: 10.1002/anie.200803842

      Thumbnail image of graphical abstract

      Golden opportunity: A terminal mononuclear gold(I) hydride complex has been stabilized by an N-heterocyclic carbene ligand (see picture: Au orange, N blue, C gray). The complex is stable to a wider range of conditions than other transition metal hydride compounds and reacts to form a number of different gold(I) species.

    29. Host–Guest Systems

      Template and pH-Mediated Synthesis of Tetrahedral Indium Complexes [Cs⊂{In4(L)4}]+ and [In4(HNL)4]4+: Breaking the Symmetry of N-Centered C3 (L)3− To Give Neutral [In4(L)4] (pages 8941–8945)

      Rolf W. Saalfrank, Harald Maid, Andreas Scheurer, Frank W. Heinemann, Ralph Puchta, Walter Bauer, Daniel Stern and Dietmar Stalke

      Article first published online: 29 OCT 2008 | DOI: 10.1002/anie.200804225

      Thumbnail image of graphical abstract

      Molecular Kinder eggs are generated from N-centered tripodal heptadentate tris(1,3-diketonate) ions (L3−) in the presence of indium ions. The tetrahedral complexes host a cesium ion ([Cs⊂{In4(L)4}]+, see picture) or four protons. Deprotonation of the species [In4(HNL)4]4+ generates the empty cage compound [In4(L)4], which comes with a break of the symmetry in the initial C3-symmetric tripodal ligand.

    30. Heterogeneous Catalysis

      Colloidally Prepared Nanoparticles for the Synthesis of Structurally Well-Defined and Highly Active Heterogeneous Catalysts (pages 8946–8949)

      Birte Jürgens, Holger Borchert, Kirsten Ahrenstorf, Patrick Sonström, Angelika Pretorius, Marco Schowalter, Katharina Gries, Volkmar Zielasek, Andreas Rosenauer, Horst Weller and Marcus Bäumer

      Article first published online: 16 OCT 2008 | DOI: 10.1002/anie.200802188

      Thumbnail image of graphical abstract

      Structural control by application of ligand-stabilized nanoparticles in heterogeneous catalysis: Highly active and structurally well-defined NiPt nanocrystals can be obtained by colloidal synthesis. When deposited on suitable supports they show immediate activity without any oxidative or thermal pretreatment. The picture shows the development of the catalytic activity of supported colloidal NiPt nanoparticles for the oxidation of CO at 170 °C.

    31. Magnetic Nanoparticles

      Inductive Heating for Organic Synthesis by Using Functionalized Magnetic Nanoparticles Inside Microreactors (pages 8950–8953)

      Sascha Ceylan, Carsten Friese, Christian Lammel, Karel Mazac and Andreas Kirschning

      Article first published online: 16 OCT 2008 | DOI: 10.1002/anie.200801474

      Thumbnail image of graphical abstract

      The heat is on! Ferromagnetic materials heated by induction in an electromagnetic field have found synthetic application. Best results were obtained when superparamagnetic nanoparticles coated with SiO2 were incorporated in a microfluidic reactor and transformations were performed under flow conditions. These magnetic particles can be doped with Pd and used as heated heterogeneous catalysts.

    32. Tetrapyrrole Pigments

      Blue Luminescence of Ripening Bananas (pages 8954–8957)

      Simone Moser, Thomas Müller, Marc-Olivier Ebert, Steffen Jockusch, Nicholas J. Turro and Bernhard Kräutler

      Article first published online: 10 OCT 2008 | DOI: 10.1002/anie.200803189

      Thumbnail image of graphical abstract

      Yes, we have blue bananas! Ripening bananas exhibit intense blue luminescence under UV light. Their luminescence arises from fluorescent chlorophyll catabolites which accumulate in the banana peels during ripening; their natural further conversion into nonfluorescent catabolites is specifically inhibited by a previously unrecognized chemical modification.

    33. Nanoreactors

      A Chip-Sized Nanoscale Monolithic Chemical Reactor (pages 8958–8960)

      Alexander Popp and Jörg J. Schneider

      Article first published online: 10 OCT 2008 | DOI: 10.1002/anie.200802954

      Thumbnail image of graphical abstract

      Processes on nanometer-scale dimensions are possible in a mechanically stable, flexible, and monolithic porous 3D carbon nanotube structure (see picture). The nanoscale chemical reactor exhibits an extremely high surface-to-volume ratio of up to 2×107 m2 m3, which depends on the tube diameter and tube separation. This exceeds values for current microreactors by at least two orders of magnitude.

    34. Microimaging

      One- and Two-Dimensional NMR Spectroscopy with a Magnetic-Resonance Force Microscope (pages 8961–8963)

      Kai W. Eberhardt, Christian L. Degen, Andreas Hunkeler and Beat H. Meier

      Article first published online: 16 OCT 2008 | DOI: 10.1002/anie.200802978

      Thumbnail image of graphical abstract

      At the micrometer scale: Chemical interactions at the atomic level have been characterized with localized spectroscopy by using magnetic-resonance force microscopy to locate slices of 2.0 μm thickness in a heterogeneous sample (see picture). To recover the chemical-shift information, the field gradient was temporarily switched off by removing its source mechanically. This technique allows high-resolution one- and two-dimensional NMR spectra to be recorded.

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      Preview: Angew. Chem. Int. Ed. 47/2008 (page 8967)

      Article first published online: 29 OCT 2008 | DOI: 10.1002/anie.200890237

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