Angewandte Chemie International Edition

Cover image for Vol. 48 Issue 42

October 5, 2009

Volume 48, Issue 42

Pages 7707–7939

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Author Profile
    7. Obituary
    8. Book Review
    9. Highlights
    10. Minireview
    11. Review
    12. Communications
    13. Preview
    1. Cover Picture: Synthesis of Cyclopamine Using a Biomimetic and Diastereoselective Approach (Angew. Chem. Int. Ed. 42/2009) (page 7707)

      Athanassios Giannis, Philipp Heretsch, Vasiliki Sarli and Anne Stößel

      Version of Record online: 22 SEP 2009 | DOI: 10.1002/anie.200904019

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      A biomimetic synthesis of the potent anticancer drug cyclopamine that features a C[BOND]H activation/hydroxylation and a ring contraction/expansion is described by A. Giannis and co-workers in their Communication on page 7911 ff. The picture shows the structure of cyclopamine, the first inhibitor of hedgehog signaling (discovered in drosophilia); Veratrum californicum; a cyclopic sheep; and Homer, who first reported a cyclops in the Odyssey.

  2. Inside Cover

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Author Profile
    7. Obituary
    8. Book Review
    9. Highlights
    10. Minireview
    11. Review
    12. Communications
    13. Preview
    1. Inside Cover: Formation and Characterization of the Iridium Tetroxide Molecule with Iridium in the Oxidation State +VIII (Angew. Chem. Int. Ed. 42/2009) (page 7708)

      Yu Gong, Mingfei Zhou, Martin Kaupp and Sebastian Riedel

      Version of Record online: 22 SEP 2009 | DOI: 10.1002/anie.200904022

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      Although +VI has long been the highest experimentally known oxidation state of Ir, the +VIII oxidation state has been produced and identified in low-temperature noble gas matrices of iridium tetroxide. M. F. Zhou, S. Riedel, and co-workers describe in their Communication on page 7879 ff. how the compound is formed by co-depositing Ir atoms with mixtures of O2 and a noble gas onto a CsI surface at 4–6 K. Theoretical analysis indicates that it is a d1 species with the formal oxidation state IrVIII.

  3. Graphical Abstract

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

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

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Author Profile
    7. Obituary
    8. Book Review
    9. Highlights
    10. Minireview
    11. Review
    12. Communications
    13. Preview
    1. Uli Kazmaier (page 7730)

      Version of Record online: 16 SEP 2009 | DOI: 10.1002/anie.200904771

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      “My favorite subject at school was biology. The biggest problem that scientists face is global warming. …” This and more about Uli Kazmaier can be found on page 7730.

  6. Obituary

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Author Profile
    7. Obituary
    8. Book Review
    9. Highlights
    10. Minireview
    11. Review
    12. Communications
    13. Preview
    1. Roland Köster (1924–2009) (pages 7731–7732)

      Bernd Wrackmeyer

      Version of Record online: 15 SEP 2009 | DOI: 10.1002/anie.200904401

  7. Book Review

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Author Profile
    7. Obituary
    8. Book Review
    9. Highlights
    10. Minireview
    11. Review
    12. Communications
    13. Preview
    1. Classics in Spectroscopy. Isolation and Structure Elucidation of Natural Products. By Stefan Berger and Dieter Sicker. (pages 7733–7734)

      Peter Spiteller

      Version of Record online: 30 SEP 2009 | DOI: 10.1002/anie.200904430

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      Wiley-VCH, Weinheim 2009. 645 pp., softcover € 79.00.—ISBN 978-3527325160

  8. Highlights

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

      Highly Convergent Synthesis of Peluroside A (pages 7736–7739)

      Paul E. Floreancig

      Version of Record online: 8 SEP 2009 | DOI: 10.1002/anie.200903480

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      When quality and quantity both count: Fragments were coupled through aldol reactions in a highly convergent synthesis of the microtubule-binding agent peluroside A (1; see retrosynthetic analysis). The approach is amenable to the preparation of analogues and to the synthesis of suitable quantities of material for biological studies. Xc=benzyloxazolidinone, MOM=methoxymethyl, TBS=tert-butyldimethylsilyl, Bn=benzyl, TES=triethylsilyl, PMB=p-methoxybenzyl.

    2. Polyyne Structures

      Synthesis and Structural Analysis of One-Dimensional sp-Hybridized Carbon Chain Molecules (pages 7740–7743)

      Sanghee Kim

      Version of Record online: 10 SEP 2009 | DOI: 10.1002/anie.200904145

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      Revelation: The synthesis and characterization of sp-hybridized carbon chain molecules, such as carbyne and polyyne, have been challenging topics in chemistry. Recent research on the synthesis and X-ray crystallographic analysis of a series of tBu-end-capped polyynes provides empirical evidence for the linear structure of sp-hybridized carbon chains.

  9. Minireview

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

      Applications of Protein Biochips in Biomedical and Biotechnological Research (pages 7744–7751)

      Dirk Weinrich, Pascal Jonkheijm, Christof M. Niemeyer and Herbert Waldmann

      Version of Record online: 15 SEP 2009 | DOI: 10.1002/anie.200901480

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      Biochip whys and wherefores: Protein biochips are becoming increasingly accessible. But what are they currently being used for? The integration of these assay and analysis platforms into biomedical and biotechnological research has substantially expanded the repertoire of methods available for proteomics and biomarker research and drug development.

  10. Review

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

      Graphene: The New Two-Dimensional Nanomaterial (pages 7752–7777)

      C. N. R. Rao, A. K. Sood, K. S. Subrahmanyam and A. Govindaraj

      Version of Record online: 25 SEP 2009 | DOI: 10.1002/anie.200901678

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      Carbon sheets: Graphene is a fascinating new nanomaterial that has attracted the attention of a large body of scientists, and in particular chemists. This Review describes the synthesis, characterization, and structure of graphene, presents its physical properties, and shows its potential areas of use. The picture shows a high-resolution STM image of a graphene monolayer.

  11. Communications

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

      A Low-Temperature Molecular Approach to Highly Conductive Tin-Rich Indium Tin Oxide Thin Films with Durable Electro-Optical Performance (pages 7778–7782)

      Yilmaz Aksu and Matthias Driess

      Version of Record online: 7 JUL 2009 | DOI: 10.1002/anie.200901204

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      Save energy, smile! Highly conductive tin-rich indium tin oxide (ITO) composites are easily accessible using the molecular precursor Sn(tBuO)3In. The as-prepared transparent and highly conductive thin films on glass substrates are atomically flat and show the best performance to date in ITO-based electroluminescent applications.

    2. Biotechnology

      Directed Evolution of Orthogonal Ligand Specificity in a Single Scaffold (pages 7783–7786)

      Michael J. McLachlan, Karuppiah Chockalingam, Ka Chun Lai and Huimin Zhao

      Version of Record online: 11 SEP 2009 | DOI: 10.1002/anie.200903413

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      Two highly sensitive ligand–receptor pairs created from a single protein scaffold were fully orthogonal both to the native ligand–receptor pair and to one another. The wild-type receptor and two mutants were activated specifically by their respective ligands (represented by red shapes in the picture) when used to control the expression of green fluorescent protein (top row), mCherry (middle row), and yellow fluorescent protein (bottom row) in yeast.

    3. Silver Bipyramids

      Plasmon-Mediated Synthesis of Silver Triangular Bipyramids (pages 7787–7791)

      Jian Zhang, Shuzhou Li, Jinsong Wu, George C. Schatz and Chad A. Mirkin

      Version of Record online: 16 SEP 2009 | DOI: 10.1002/anie.200903380

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      Color-tuned: Monodisperse silver right-triangular bipyramids (see SEM image) were formed by photoinduced synthesis in high yield. The edge length of the bipyramids can be easily controlled by the wavelength of excitation light (see diagram).

    4. Alloys

      Ferromagnetic Mesostructured Alloys: Design of Ordered Mesostructured Alloys with Multicomponent Metals from Lyotropic Liquid Crystals (pages 7792–7797)

      Yusuke Yamauchi, Masaki Komatsu, Minekazu Fuziwara, Yoshihiro Nemoto, Keisuke Sato, Tokihiko Yokoshima, Hiroaki Sukegawa, Kouichiro Inomata and Kazuyuki Kuroda

      Version of Record online: 10 SEP 2009 | DOI: 10.1002/anie.200902934

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      Magnets made to order: Highly ordered multicomponent mesostructured alloys with controllable compositions have been synthesized [see TEM image and electron diffraction patterns (inset)]. The saturation magnetization of the alloys can be controlled by changing the ratio of metal components. New functions that are not found in a single metal system can be realized by alloying, thus opening up a range of new magnetic applications for these materials.

    5. Protein Modification

      Thiyl Glycosylation of Olefinic Proteins: S-Linked Glycoconjugate Synthesis (pages 7798–7802)

      Nicola Floyd, Balakumar Vijayakrishnan, Julia R. Koeppe and Benjamin G. Davis

      Version of Record online: 8 SEP 2009 | DOI: 10.1002/anie.200903135

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      Tagged for thiolation: A novel glycoconjugation strategy utilizes a non-natural olefin-containing amino acid (homoallylglycine, Hag) as a “tag” for modification and a photoinitiated hydroglycothiolation reaction that is selective only for the Hag olefinic “tag”. Application of this method to a number of model proteins allowed complete and precise site-selective glycosylation generating glycoconjugates that include, for example, virus-like particles displaying up to 180 glycans at preselected positions (see scheme).

    6. Noncovalent Interactions

      Quantification of a CH–π Interaction Responsible for Chiral Discrimination and Evaluation of Its Contribution to Enantioselectivity (pages 7803–7808)

      Romen Carrillo, Matías López-Rodríguez, Victor S. Martín and Tomás Martín

      Version of Record online: 8 SEP 2009 | DOI: 10.1002/anie.200903281

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      Good things come in small interactions: The high chiral discrimination displayed by a new receptor with ammonium salts of aromatic α-amino acid methyl esters is mainly the result of one of the weakest noncovalent interactions, the CH–π interaction (see picture). The interaction has been identified and quantified, and its contribution to the chiral recognition process has been evaluated.

    7. Chemical Genetics

      Cardiosulfa, a Small Molecule that Induces Abnormal Heart Development in Zebrafish, and Its Biological Implications (pages 7809–7812)

      Sung-Kyun Ko, Hui Juan Jin, Da-Woon Jung, Xizhe Tian and Injae Shin

      Version of Record online: 15 SEP 2009 | DOI: 10.1002/anie.200902370

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      A change of heart: Cardiosulfa, a small molecule that induces heart deformation during zebrafish development, has been identified by using a forward chemical-genetic approach. Zebrafish embryos exposed to cardiosulfa have a narrow and elongated heart within an enlarged pericardial sac (see picture; heart marked with green fluorescent protein).

    8. Cell Encapsulation

      A Metal–Collagen Peptide Framework for Three-Dimensional Cell Culture (pages 7813–7817)

      Marcos M. Pires, David E. Przybyla and Jean Chmielewski

      Version of Record online: 15 SEP 2009 | DOI: 10.1002/anie.200902375

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      It won′t overstay its welcome: Metal ions trigger the rapid assembly of a triple-helical collagen-based peptide with ligands at the ends and center into a fibrous three-dimensional mesh under physiological conditions (see picture). Importantly for applications in regenerative medicine, a mild chelating agent causes rapid disassembly of the mesh. Human endothelial cells were readily encapsulated and cultured within the collagen-peptide network.

    9. Sensors

      Multiplexed Analysis of Hg2+ and Ag+ Ions by Nucleic Acid Functionalized CdSe/ZnS Quantum Dots and Their Use for Logic Gate Operations (pages 7818–7821)

      Ronit Freeman, Tali Finder and Itamar Willner

      Version of Record online: 11 SEP 2009 | DOI: 10.1002/anie.200902395

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      A logical analysis: Nucleic acid functionalized CdSe/ZnS quantum dots are used for the optically selective multiplexed analysis of Hg2+ and Ag+ and the activation of logic gates in the presence of Ag+ and Hg2+, and for the activation of logic gates, by using the ions as inputs.

    10. DNA Sensors

      Secondary-Structure-Inducible Ligand Fluorescence Coupled with PCR (pages 7822–7824)

      Fumie Takei, Masako Igarashi, Masaki Hagihara, Yoshimi Oka, Yoshihiro Soya and Kazuhiko Nakatani

      Version of Record online: 11 SEP 2009 | DOI: 10.1002/anie.200902449

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      Not second fiddle: Hairpin secondary structures at the 5′ end of the PCR primer are transformed into a double-stranded form as the PCR proceeds. A fluorescent molecule (DANP) can bind to the single cytosine bulge (C-bulge) in the hairpin structure and emit characteristic fluorescence. When the PCR primer labeled with a C-bulge hairpin tag is used in the presence of DANP, fluorescence from the DANP-C-bulge complex decreases as the PCR proceeds.

    11. Nanostructures

      Cyclic Self-Assembled Structures of Chlorophyll Dyes on HOPG by the Dendron Wedge Effect (pages 7825–7828)

      Shinobu Uemura, Sanchita Sengupta and Frank Würthner

      Version of Record online: 11 SEP 2009 | DOI: 10.1002/anie.200902801

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      A molecular cake: Zinc chlorins with different dendron wedges can form linear or circular self-assembled structures with different molecular packing. In particular, zinc chlorins with six alkyl chains in the dendron group self-assemble into hexameric cyclic structures on HOPG (see picture). Such cyclic structures are reminiscent of (bacterio)chlorophyll organization in natural light-harvesting systems.

    12. UV/Vis Spectroscopy

      Gas-Phase Synthesis and Intense Visible Absorption of Tryptophan–Gold Cations (pages 7829–7832)

      Rodolphe Antoine, Franck Bertorelle, Michel Broyer, Isabelle Compagnon, Philippe Dugourd, Alexander Kulesza, Roland Mitrić and Vlasta Bonačić-Koutecký

      Version of Record online: 11 SEP 2009 | DOI: 10.1002/anie.200902882

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      The color of gold: The tryptophan–gold cation was synthesized and its unique optical properties were studied experimentally and by ab initio calculations (see picture). The complex exhibits strong absorption in the visible region owing to charge-transfer excitations, which make gold complexes attractive for bioapplications.

    13. Biological Structures

      Consecutive Formation of G-Quadruplexes in Human Telomeric-Overhang DNA: A Protective Capping Structure for Telomere Ends (pages 7833–7836)

      Yan Xu, Takumi Ishizuka, Kaori Kurabayashi and Makoto Komiyama

      Version of Record online: 15 SEP 2009 | DOI: 10.1002/anie.200903858

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      The end of the line: Structural studies demonstrate the consecutive formation of G-quadruplexes in human single-stranded telomeric-overhang DNA. A higher-order DNA G-quadruplex structure was found to protect DNA double-strand ends from being recognized as double-strand breaks and to direct against nuclease hydrolysis, suggesting that the superhelix structure may provide protective “capping” for the telomere ends.

    14. Self-Assembly

      Hollow Six-Stranded Helical Columns of a Helicene (pages 7837–7840)

      Maxim A. Shcherbina, Xiang-bing Zeng, Timur Tadjiev, Goran Ungar, S. H. Eichhorn, Karen E. S. Phillips and Thomas J. Katz

      Version of Record online: 8 SEP 2009 | DOI: 10.1002/anie.200903658

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      Do the twist: A helicenebisquinone (see formula), both enantiopure and racemic, forms hexagonal columnar phases in which the internal structures of the columns are 132 hollow helices comprising six-molecule repeat units (see axial and side views). The enantiopure compound forms a true hexagonal structure; the racemate segregates enantiomers into right and left helical columns that are interlocked and longitudinally displaced for optimal packing.

    15. Synthetic Methods

      Iridium-Catalyzed Regio- and Enantioselective N-Allylation of Indoles (pages 7841–7844)

      Levi M. Stanley and John F. Hartwig

      Version of Record online: 16 SEP 2009 | DOI: 10.1002/anie.200904338

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      Iridium is blind to C: Highly regio- and enantioselective, iridium-catalyzed N-allylations of indoles, which complement the more common reactivity of indoles as carbon nucleophiles, have been developed (see scheme). These reactions form highly enantioenriched N-allylindoles, which are readily transformed into enantioenriched 3-(1H-indol-1-yl)-N-methyl-3-aryl propan-1-amines, dihydropyrrolo[1,2-a]indoles, and indol-1-yl propanoic acids.

    16. Smart Nanocrystals

      Coating Nanocrystals with Amphiphilic Thermosensitive Copolymers (pages 7845–7849)

      Jian Qin, Yun Suk Jo and Mamoun Muhammed

      Version of Record online: 15 SEP 2009 | DOI: 10.1002/anie.200900489

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      Well-dressed: A new method was developed to produce thermosensitive nanocrystals (NCs) by coating the NCs with an amphiphilic copolymer consisting of poly(maleic anhydride-alt-1-octadecene) (PMAO) and poly(N-isopropylacrylamide) (PNIPAAm; see photograph of coated Fe3O4 NCs at 20 °C and 40 °C). The method is general for all hydrophobic NCs produced by thermolysis.

    17. Nerve Agent Sensors

      Hydroxy Oximes as Organophosphorus Nerve Agent Sensors (pages 7850–7852)

      Trevor J. Dale and Julius Rebek Jr.

      Version of Record online: 15 SEP 2009 | DOI: 10.1002/anie.200902820

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      Find and destroy: A series of oximes were constructed to simultaneously detect and detoxify organophosphorus-based nerve agents. They function as optical sensors employing the oxime reactivity and incorporating a β-hydroxyl group to undergo an intramolecular cyclization from the intermediate oxime–organophosphorus species. The generated isoxazole produces an enhanced fluorescent signal that reports on the presence and destruction of the nerve agent.

    18. Natural Products

      Construction of Two Vicinal Quaternary Carbons by Asymmetric Allylic Alkylation: Total Synthesis of Hyperolactone C and (−)-Biyouyanagin A (pages 7853–7856)

      Chao Du, Liqi Li, Ying Li and Zhixiang Xie

      Version of Record online: 11 SEP 2009 | DOI: 10.1002/anie.200902908

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      Call on triple A: Palladium-catalyzed asymmetric allylic alkylation (Pd-AAA; see scheme) has enabled a concise and efficient synthesis of hyperolactone C and (−)-biyouyanagin A in only six (20 % overall yield) and seven (8 % overall yield) steps, respectively. The enantiomers of these natural products were also prepared by exploiting the same methodology.

    19. Heterocycles

      Consecutive C[BOND]H Functionalization Reactions of Arenes: Synthesis of Carbo- and Heteropolycyclic Skeletons (pages 7857–7861)

      Samuel Suárez-Pantiga, David Palomas, Eduardo Rubio and José M. González

      Version of Record online: 11 SEP 2009 | DOI: 10.1002/anie.200902989

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      Doubling the bet: Two C[BOND]H bonds become functionalized upon exposure of ω-aryl propargylic tosylates to Sc(OTf)3 (see scheme). The reaction involves a new domino process that can tolerate both electron-withdrawing and -donating substituents on the arene unit. Different carbo- and heterocyclic frameworks can be assembled by using this approach to formally conquer the hydroarylation process.

    20. Heterogeneous Catalysis

      Propene Epoxidation with Dioxygen Catalyzed by Gold Clusters (pages 7862–7866)

      Jiahui Huang, Tomoki Akita, Jérémy Faye, Tadahiro Fujitani, Takashi Takei and Masatake Haruta

      Version of Record online: 15 SEP 2009 | DOI: 10.1002/anie.200903011

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      Size matters: Gold clusters (<2.0 nm), but not gold nanoparticles, deposited on alkaline-treated titanosilicalite-1 allow O2 and H2O to react to give hydroperoxides (-OOH). These transfer to neighboring Ti sites to form Ti-OOH (see scheme), which is responsible for propene epoxidation to give propene epoxide (PO).

    21. Molecular Switches

      Switching the Cubic Nonlinear Optical Properties of an Electro-, Halo-, and Photochromic Ruthenium Alkynyl Complex Across Six States (pages 7867–7870)

      Katy A. Green, Marie P. Cifuentes, T. Christopher Corkery, Marek Samoc and Mark G. Humphrey

      Version of Record online: 16 SEP 2009 | DOI: 10.1002/anie.200903027

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      More than on and off: The title complex (see picture) comprises addressable modules that respond independently to protic (alkynyl ligand⇄vinylidene ligand), electrochemical (metal-centered redox: RuII⇄RuIII), and photochemical (dithienylperfluorocyclopentene ring-opening⇄ring-closing) stimuli. The six states are interconverted along seven pathways, all of which result in distinct changes to cubic nonlinearity.

    22. Organic–Inorganic Hybrid Composites

      Flexible Hybrid Semiconductors with Low Thermal Conductivity: The Role of Organic Diamines (pages 7871–7874)

      Xiaoying Huang, Mojgan Roushan, Thomas J. Emge, Wenhua Bi, Suraj Thiagarajan, Jen-Hao Cheng, Ronggui Yang and Jing Li

      Version of Record online: 10 SEP 2009 | DOI: 10.1002/anie.200903234

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      Flexible conductors: A unique type of organic–inorganic hybrid semiconductor crystals have been synthesized that are flexible and have low thermal conductivity. The hybrids consist of ZnTe layers connected by various diamines (see picture for examples; C gray, N blue, Te red, Zn large pale blue spheres).

    23. Tautomeric Switches

      Exploiting Tautomerism for Switching and Signaling (pages 7875–7878)

      Liudmil Antonov, Vera Deneva, Svilen Simeonov, Vanya Kurteva, Daniela Nedeltcheva and Jakob Wirz

      Version of Record online: 15 SEP 2009 | DOI: 10.1002/anie.200903301

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      Good form: Attaching a flexible piperidine unit to 4-(phenyldiazenyl)naphthalen-1-ol allows construction of a tautomeric switch, where directed shift of the tautomeric equilibrium can be achieved through protonation and deprotonation (see picture). The developed molecular switch shows acceptable complexation with small alkali- and alkaline-earth-metal ions and forms a promising base for further development of effective molecular sensors.

    24. High Oxidation States

      Formation and Characterization of the Iridium Tetroxide Molecule with Iridium in the Oxidation State +VIII (pages 7879–7883)

      Yu Gong, Mingfei Zhou, Martin Kaupp and Sebastian Riedel

      Version of Record online: 11 JUL 2009 | DOI: 10.1002/anie.200902733

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      A state of eight: Iridium atoms insert into dioxygen to form iridium dioxide molecules in solid noble-gas matrices. Annealing allows formation of the iridium dioxide superoxide complex [(η1-O2)IrO2], which isomerizes under IR irradiation to the iridium dioxide peroxide complex [(η2-O2)IrO2]. These complexes photochemically rearrange to the more stable iridium tetroxide molecule with an iridium oxidation state of +VIII (see scheme; Ir black, O red).

    25. Carbon Nitride Nanoparticles

      Highly Ordered Mesoporous Carbon Nitride Nanoparticles with High Nitrogen Content: A Metal-Free Basic Catalyst (pages 7884–7887)

      Xin Jin, Veerappan V. Balasubramanian, Sakthivel T. Selvan, Dhanashri P. Sawant, Murugulla A. Chari, G. Q. Lu and Ajayan Vinu

      Version of Record online: 8 SEP 2009 | DOI: 10.1002/anie.200903674

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      Nitrogen-rich carbon nitride is obtained as ultrasmall, discrete, mesoporous nanoparticles (see picture) by reaction of ethylenediamine with CCl4 in the nanochannels of a mesoporous silica template. Its high nitrogen content, large surface area, and large pore volume make it a highly active catalyst for transesterification of β-keto esters of aryl, aliphatic, and cyclic primary alcohols.

    26. Rare-Earth Complexes

      Reduction of Transition-Metal-Coordinated Carbon Monoxide by a Rare-Earth Hydride Cluster: Isolation of Well-Defined Heteromultimetallic Oxycarbene, Oxymethyl, Carbene, and Methyl Complexes (pages 7888–7891)

      Yasumasa Takenaka, Takanori Shima, Jens Baldamus and Zhaomin Hou

      Version of Record online: 11 SEP 2009 | DOI: 10.1002/anie.200903660

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      Reduction junction: Tetranuclear yttrium polyhydride complex 1 reduces coordinated CO in transition-metal complexes to give novel heterometallic oxycarbene, oxymethyl, carbene oxo, and methyl oxo complexes (see scheme). The reaction patterns depend on the nature of the transition-metal carbonyl complexes.

    27. Organocatalysis

      Asymmetric Organocatalytic Cascade Reactions with α-Substituted α,β-Unsaturated Aldehydes (pages 7892–7894)

      Patrizia Galzerano, Fabio Pesciaioli, Andrea Mazzanti, Giuseppe Bartoli and Paolo Melchiorre

      Version of Record online: 10 SEP 2009 | DOI: 10.1002/anie.200903803

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      Time to α-branch out! The first highly enantioselective aminocatalytic activation of α-substituted α,β-unsaturated aldehydes is presented. The chiral primary amine 1 selectively activates α-branched enals toward a well-defined iminium ion/enamine reaction sequence for both Friedel–Crafts/amination and sulfa-Michael/amination cascades. The valuable multifunctional products, having two contiguous sterocenters, are isolated in high enantiomeric purity.

    28. Cycloaromatization

      A Palladium-Catalyzed Oxidative Cycloaromatization of Biaryls with Alkynes Using Molecular Oxygen as the Oxidant (pages 7895–7898)

      Zhuangzhi Shi, Shengtao Ding, Yuxin Cui and Ning Jiao

      Version of Record online: 8 SEP 2009 | DOI: 10.1002/anie.200903975

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      Dual activation of C[BOND]H bonds has enabled the preparation of polycyclic aromatics from arylindoles and arylbenzofurans in the absence of a directing group, and with using O2 as the oxidant (see scheme). Synthetically and medicinally important polycyclic aromatics have been easily prepared, and some of the resulting polycyclic heteroaromatics exhibit intense fluorescence.

    29. Biomimetic Synthesis

      Et2SBr⋅SbCl5Br: An Effective Reagent for Direct Bromonium-Induced Polyene Cyclizations (pages 7899–7903)

      Scott A. Snyder and Daniel S. Treitler

      Version of Record online: 15 SEP 2009 | DOI: 10.1002/anie.200903834

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      It's all about reactivity: Although bromonium-induced cation–π cyclizations are commonly utilized by nature to fashion six-membered rings from a diverse set of polyene precursors, no general laboratory method exists that can achieve the same breadth of substrate scope. An easily synthesized and handled reagent is described (see scheme) that is capable of directly, broadly, and rapidly effecting such reactions in good yield with a variety of geraniol, farnesol, and nerol derivatives.

    30. Antitumor Agents

      A Single Slow Electron Triggers the Loss of Both Chlorine Atoms from the Anticancer Drug Cisplatin: Implications for Chemoradiation Therapy (pages 7904–7907)

      Janina Kopyra, Constanze Koenig-Lehmann, Ilko Bald and Eugen Illenberger

      Version of Record online: 10 SEP 2009 | DOI: 10.1002/anie.200903874

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      Leaner, meaner cisplatin: Dissociative electron attachment to the anticancer drug cisplatin (1) shows intense resonances at very low energies, which result in Pt[BOND]Cl bond cleavage. A single low-energy electron can trigger the loss of both chlorine atoms from cisplatin (see scheme), thereby forming [Pt(NH3)2]. This complex is the reactive intermediate to form cisplatin–DNA adducts, which consequently inhibit DNA replication.

    31. Ionic Liquids

      Tunable Aryl Alkyl Ionic Liquids (TAAILs): The Next Generation of Ionic Liquids (pages 7908–7910)

      Sebastian Ahrens, Anke Peritz and Thomas Strassner

      Version of Record online: 16 SEP 2009 | DOI: 10.1002/anie.200903399

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      The combination of aromatic and aliphatic substituents at the imidazolium ring leads to a new generation of imidazolium-based ionic liquids (TAAILs: tunable aryl alkyl ionic liquids; see charge distribution of the methoxyphenyl methyl derivative). Electronic interaction between the aromatic substituent and the imidazolium core allows the properties of these species to be tuned more precisely than is possible for currently available ionic liquids.

    32. Cyclopamine

      Synthesis of Cyclopamine Using a Biomimetic and Diastereoselective Approach (pages 7911–7914)

      Athanassios Giannis, Philipp Heretsch, Vasiliki Sarli and Anne Stößel

      Version of Record online: 9 JUL 2009 | DOI: 10.1002/anie.200902520

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      From Homer to hedgehog: Cyclopamine, the first inhibitor of the hedgehog signaling pathway, causes cyclopia in embryos but in adults it is a potent anticancer drug. A concise biomimetic and diastereoselective synthesis of cyclopamine (2) starting from commercially available dehydroepiandrosterone (1) now also provides access to several analogues.

    33. Carbynes

      tert-Butyl-End-Capped Polyynes: Crystallographic Evidence of Reduced Bond-Length Alternation (pages 7915–7919)

      Wesley A. Chalifoux, Robert McDonald, Michael J. Ferguson and Rik R. Tykwinski

      Version of Record online: 7 AUG 2009 | DOI: 10.1002/anie.200902760

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      Cumulene or polyyne? The synthesis and X-ray crystallographic analysis of a series of polyynes up to 20 Csp atoms in length and end-capped with tert-butyl groups has been achieved. The structural data show a distinct reduction in the bond-length alternation as a function of the polyyne length, but this trend appears to saturate before a cumulenic-like structure is achieved.

    34. Heteroborates

      Synthesis and Characterization of Digerma-closo-dodecaborate: A Higher Homologue of Icosahedral ortho-Carborane (pages 7920–7923)

      Claudia Nickl, Dominik Joosten, Klaus Eichele, Cäcilia Maichle-Mössmer, Karl W. Törnroos and Lars Wesemann

      Version of Record online: 11 SEP 2009 | DOI: 10.1002/anie.200903300

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      Missing link: Starting from germanium(II) bromide, decaborane, and triethylamine, a dimeric 2,2′-bis(1,2-digerma-closo-dodecaborate) was prepared. Reductive cleavage yielded the monomeric dianion [Ge2B10H10]2−. With alkyl halides, neutral disubstituted species were obtained (see example), which were fully characterized by NMR spectroscopy and X-ray crystallography. The gap in the series of Group 14 di-hetero-closo-dodecaboranes is now closed.

    35. Siderophores

      Structural Basis and Stereochemistry of Triscatecholate Siderophore Binding by FeuA (pages 7924–7927)

      Florian Peuckert, Marcus Miethke, Alexander G. Albrecht, Lars-Oliver Essen and Mohamed A. Marahiel

      Version of Record online: 11 SEP 2009 | DOI: 10.1002/anie.200902495

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      An iron will: The cyclic depsipeptide ferribacillibactin ([FeIIIBB]3−) is tightly bound by the siderophore binding protein FeuA (see picture). The FeuA/[FeIIIBB]3− complex contains a basic triad, which interacts with the triscatecholate unit of the siderophore. H2O molecules stabilize [FeIIIBB]3− in an energetically unfavored conformation. FeuA allows only a Λ configuration at the ferri-triscatecholate metal center and can thus alter the configuration of a Δ species upon binding.

    36. Phototherapeutic Agents

      Photoactive Hybrid Nanomaterial for Targeting, Labeling, and Killing Antibiotic-Resistant Bacteria (pages 7928–7931)

      Cristian A. Strassert, Matthias Otter, Rodrigo Q. Albuquerque, Andrea Höne, Yolanda Vida, Berenike Maier and Luisa De Cola

      Version of Record online: 3 SEP 2009 | DOI: 10.1002/anie.200902837

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      Killing with light: A multifunctional nanosized zeolite L uses amino groups, a luminescent dye, and a 1O2 producer to target, label, and kill pathogenic and antibiotic-resistant bacteria.

    37. RNA Modifications

      Parallel Isotope-Based Quantification of Modified tRNA Nucleosides (pages 7932–7934)

      Tobias Brückl, Daniel Globisch, Mirko Wagner, Markus Müller and Thomas Carell

      Version of Record online: 11 SEP 2009 | DOI: 10.1002/anie.200902740

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      Modifications make a difference: An isotope-based mass spectrometry method allows the facile and quantitative analysis of modified tRNA nucleosides in various types of cells. This method could be capable of distinguishing between individual cell lines as well as between healthy tissue and cancer cells.

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