Angewandte Chemie International Edition in English

Cover image for Vol. 34 Issue 23‐24

January 5, 1996

Volume 34, Issue 23-24

Pages 2573–2795

Currently known as: Angewandte Chemie International Edition

    1. Cover Picture (Angew. Chem. Int. Ed. Engl. 23/24/1995)

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199525711

      Thumbnail image of graphical abstract

      The cover picture shows a ball-and-stick model of a multicyclophane described by an achiral K3.3 stereoelement. K3.3 graphs consist of two sets of three points where each point in one set is connected to every point in the other set. In the multicyclophane shown, these six points are the red and blue benzene rings. J. S. Siegel et al. report more on pages 2657–2660 on this multicyclophane and its D2h-symmetric isomer, which have dimensions on the order of nanometers in terms of length and kilodaltons in terms of weight. The picture was generated with the program QMView developed by Kim K. Baldridge and Jerry Greenberg at the San Diego Supercomputer Center.

  1. Reviews

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Book Reviews
    6. Author Index
    7. Subject Index
    1. Palladium-Catalyzed Reactions of Propargylic Compounds in Organic Synthesis (pages 2589–2612)

      Prof. Dr. Jiro Tsuji and Prof. Dr. Tadakatsu Mandai

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199525891

      Thumbnail image of graphical abstract

      Owing to the ready availability of propargylic alcohols and their esters by the reaction of terminal alkynes with carbonyl compounds, their Pd-catalyzed reactions hold great potential in organic synthesis. For instance, the reaction of methyl carbonate 1 with methyl acrylate (2) leads to the coupling product 3. Many reactions, including carbonylations, yield allenes that can be used in a range of subsequent reactions. THP = tetrahydropyranyl.

    2. Computer-Assisted Planning of Organic Syntheses: The Second Generation of Programs (pages 2613–2633)

      Dr. Wolf-Dietrich Ihlenfeldt and Prof. Dr. Johann Gasteiger

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526131

      To imitate the way a chemist thinks in the planning of a synthesis is the goal of the synthesis-planning program WODCA presented here. The system provides a variety of tools to be selected by the knowledgeable chemist, which guide a synthesis plan toward starting materials, exploiting long-range synthetically accessible structural similarities. The way the program operates is demonstrated for the development of suggestions for the synthesis of the calicheamicin precursors, (+)-α-bisabolene, and (+)-7,8-epoxy-2-basmen-2-one.

  2. Highlights

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Book Reviews
    6. Author Index
    7. Subject Index
    1. X-ray Crystal Structures of Cytochrome c Oxidases from Paracoccus denitrificans and Bovine Heart and Their Implications for the Molecular Mechanism of Cell Respiration (pages 2635–2637)

      Prof. Dr. Bernhard Kadenbach

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526351

      Pores with rotational symmetry, each formed from five transmembrane helices in cytochrome c oxidase, form the postulated pathways for the protons required for the biochemical reduction of O2 as well as for the protons transported across the cell (or inner mitochondrial) membrane resulting in a H+ gradient. The structures of cytochrome c oxidase from a bacterium recently described by Michel et al. and from bovine heart by Yoshikawa et al. corroborate many previous results on the structure and function of this enzyme and disprove others.

    2. New Evidence Concerning the Structure of Amorphous Red Phosphorus (pages 2637–2638)

      Prof. Dr. Hans Hartl

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526371

      Thumbnail image of graphical abstract

      Helical strands from P2 and P10 units (see structure below), recently predicted by ab initio calculations to be thermodynamically stable, and shortly thereafter discovered as a structural element in (CuI)3P12, might be the major component of amorphous red phosphorus. Radial distribution functions calculated on the basis of this structural model are in very good agreement with experimentally determined diagrams.

  3. Communications

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Book Reviews
    6. Author Index
    7. Subject Index
    1. Regio- and Diastereoselective Synthesis of β-Amino Ketones by Addition of Imines to Iminium Salts (pages 2639–2640)

      Dipl.-Chem. Michael Arend and Prof. Dr. Nikolaus Risch

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526391

      Thumbnail image of graphical abstract

      High regioselectivity, good yields, and mild reaction conditions are the advantages of the reaction of iminium salts 1 with imines 2 to afford the Mannich bases 3. Since the amino group in 3 can be substituted readily, this approach enables the simple regioselective functionalization of ketones—an important goal in synthesis.

    2. Asymmetric Sulfide Oxidation with Vanadium Catalysts and H2O2 (pages 2640–2642)

      Prof. Dr. Carsten Bolm and Dipl.-Chem. Frank Bienewald

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526401

      Thumbnail image of graphical abstract

      With less than 1 mol% of a chiral vanadium catalyst and aqueous H2O2 as oxidizing agent, sulfides can be converted under the simplest of conditions into optically active sulfoxides (with up to 85% ee) [Eq. (a)]. R, R′ = alkyl, aryl.

    3. The First μ(OH)-Bridged Model Complex for the Mixed-Valent FeIIFeIII Form of Hemerythrin (pages 2642–2645)

      Ursula Bossek, Dipl.-Chem. Helga Hummel, Dr. Thomas Weyhermüller, Dr. Eckhard Bili and Prof. Dr. Karl Wieghardt

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526421

      Thumbnail image of graphical abstract

      The mixed-valent FeIIFeIII complex 1 (structure shown on the right; the dashed line indicates a weak hydrogen bond to one ClOmath image counterion) with the ground state St = 1/2 is the first functional model for the mixed-valent form of the metalloprotein hemerythrin. Like the protein, 1 disproportionates autocatalytically in CH3CN to the FeIIFeII and FeIIIFeIII forms. L = 1,4,7-trimethyl-1,4,7-triazacyclonane.

      • equation image
    4. Synthesis and Structures of Triamino- and Tetraaminosilanes (pages 2645–2647)

      Karsten Wraage, Dipl.-Chem. Antje Künzel, Dr. Mathias Noltemeyer, Hans-Georg Schmidt and Prof. Dr. Herbert W. Roesky

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526451

      The first compounds of the type RSi(NH2)3 containing substituents R bound through oxygen or nitrogen to silicon are presented herein. These compounds are expected, like the isoelectronic silanetrioles RSi(OH)3, to exhibit a wide range of reactivity—selective substitutions have already been carried out—and should be ideal precursors for the preparation of dendrimers and ceramics.

    5. Fivefold Deprotonated D-Mannose as Ligand in Homoleptic Dinuclear Metalates of Trivalent Iron, Vanadium, Chromium, Aluminum, and Gallium (pages 2647–2649)

      Dipl.-Chem. Joachim Burger, Dipl.-Chem. Claudia Gack and Prof. Dr. Peter Klüfers

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526471

      Thumbnail image of graphical abstract

      Bridging by carbohydrate ligands instead of hydroxo or oxo ligands causes the formation of small complexes instead of networks for the trivalent atoms in the complexes 1 (M = Fe, V, Cr, Al, Ga; n ≈ 13). At slightly alkaline pH values all five acidic protons of the furanose form of D-mannose are split off: this pentaanion can then act as a pentadentate ligand. The crystal structure of the anion in complex 1, M = Fe, is displayed on the right.

      • equation image
    6. dad Compounds of Niobium and Tantalum: Examples of the Structural Flexibility of dad Ligands (pages 2649–2651)

      Dr. Bodo Richter, Dr. Joachim Scholz, Prof. Dr. Joachim Sieler and Prof. Dr. Karl-Heinz Thiele

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526491

      Thumbnail image of graphical abstract

      New uses for dad! Ideal examples of the flexible coordination of 1,4-diaza-1,3-butadiene (dad) ligands are the novel niobium and tantalum (dad) complexes 1 and 2. As a result of the unusual μ-η22 bridging function of two dad ligands in 1a, b, the lithium ions are located within the ligand sphere of the complexes. Irrefutable evidence of the different coordination modes is provided by 2: three types are represented in this one dinuclear niobium complex.

      • equation image
    7. Zeolite Encaged Cu(Histidine) Complexes as Mimics of Natural Cu Enzymes (pages 2652–2654)

      Dr. Bert M. Weckhuysen, An A. Verberckmoes, Ina P. Vannijvel, Josephina A. Pelgrims, Dr. Philip L. Buskens, Prof. Pierre A. Jacobs and Prof. Robert A. Schoonheydt

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526521

      Thumbnail image of graphical abstract

      Epoxidations of olefins and oxidations of alcohols can be carried out in the presence of peroxides at relatively low temperatures with Cu2+ histidine complexes that have been immobilized in zeolite cavities (structure from molecular modeling shown on the right). Combined diffuse reflectance and ESR spectroscopic studies reveal the presence of three nitrogen atoms in the first coordination sphere of Cu2+.

    8. Self-Assembly of 1,3,5-Benzenetricarboxylic Acids (Trimesic Acids) and Several Analogues in the Solid State (pages 2654–2657)

      Sergei V. Kolotuchin, Edward E. Fenlon, Dr. Scott R. Wilson, Colin J. Loweth and Prof. Steven C. Zimmerman

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526541

      Thumbnail image of graphical abstract

      More often than previously thought, the solid-state structures of carboxylic acids display hydrogen bonding motifs that differ from those of the classic carboxylic acid dimers. In studies aimed at engineering crystals with predictable structures, a specially designed tetracarboxylic acid was found to crystallize with THF to form a solid-state host–guest complex (clathrate); the host lattice is shown on the right.

    9. Synthesis and Structure of the Nanodimensional Multicyclophane “Kuratowski Cyclophane”, an Achiral Molecule with Nonplanar K3,3 Topology (pages 2657–2660)

      Chao-Tsen Chen, Dr. Peter Gantzel, Prof. Jay S. Siegel, Dr. Kim K. Baldridge, Prof. Robin B. English and Dr. Douglas M. Ho

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526571

      Thumbnail image of graphical abstract

      Topology is topical in supramolecular chemistry! Two new macrocyclophanes have been prepared with novel architectures and relative molecular masses in the kilodalton range. One of them, the compound below, displays the K3, 3 nonplanar molecular graph.

    10. Homeomorphic Isomerism in a Peptidic Macrobicycle (pages 2660–2662)

      Dr. Richard S. Wareham, Dr. Jeremy D. Kilburn, Dr. David L. Turner, Dr. Nicholas H. Rees and Dr. Duncan S. Holmes

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526601

      Thumbnail image of graphical abstract

      Bicyclic compounds can exist as in–out isomers, which can interconvert when one chain passes through the ring that it bridges, as shown schematically on the right. A novel peptide macrobicycle exhibits this property and two separate in–out isomers, which can be distinguished by their NMR spectra because of stereocenters in one of the three chains, have been separated and found to interconvert in solution over several days.

    11. Synthesis and Structure of [Li(thf)4]2(Ph2P)10Cd4] Containing a Dianion with a Cd4P10 Adamantanoid Core (pages 2662–2664)

      Dr. Michael A. Beswick, Dr. Paul R. Raithby, Christopher A. Russell, Dr. Alexander Steiner, Kerry L. Verhorevoort, Gregory N. Ward and Dr. Dominic S. Wright

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526621

      Thumbnail image of graphical abstract

      A potential single-source precursor for semiconducting cadmium phosphide phases, the title complex is prepared by nucleophilic substitution of [Cd{N(SiMe3)2}2] with Ph2PLi. The adamantanoid core of the dianion (shown on the right) contains four Cd centers and six bridging phosphido ligands; four terminal phosphides complete the coordination spheres of the Cd atoms. (For clarity the substituents on phosphorus have been omitted.)

    12. Luminescence Stimulated by Electron Transfer: Fluorescent Donor/Acceptor-Substituted Stilbenes Containing Pyrenoid and Heteroaromatic Subunits (pages 2664–2666)

      Dr. Andreas Knorr and Prof. Dr. Jörg Daub

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526641

      Thumbnail image of graphical abstract

      To correlate the electron transfer, electronic structure, and molecular structure of compounds with their optical and electrochemical properties was the motivation behind the synthesis and study of donor/acceptor-substituted stilbenoids such as 1. This particular compound displays electrochemically induced luminescence when the radical cation and radical anion are formed sequentially.

    13. Glc-PC, a New Type of Glucosidic Phospholipid (pages 2667–2669)

      Dr. Michael Mickeleit, Dr. Thomas Wieder, Dr. Klaus Buchner, Dr. Christoph Geilen, Prof. Dr. Johann Mulzer and Prof. Dr. Werner Reutter

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526671

      Thumbnail image of graphical abstract

      An efficient inhibitor of cell proliferation, the novel phospholipid 1 is not cytotoxic and in contrast to other PC derivatives does not act by inhibition of the enzyme protein kinase C. The title compound was synthesized in eight steps starting from (R)-isopropylideneglyceraldehyde in 22% overall yield.

    14. A New Dimension in Radical Chain Group Transfer Reaction by Photosensitized Electron Transfer (PET) Reductive Activation of PhSeSiR3 (pages 2669–2671)

      Dr. Ganesh Pandey and K. S. Sesha Poleshwar Rao

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526691

      Thumbnail image of graphical abstract

      Reductive cleavage of the Se[BOND]Si bond in PhSeSiR3 (R3 = Ph2tBu) leads to the generation of the corresponding silyl radical and the anion PhSe. These can be employed in situ for a large number of cyclizations, as shown schematically below. X = Cl, Br.

    15. A Highly Reactive and Catalytically Active Model System for Intradiol-Cleaving Catechol Dioxygenases: Structure and Reactivity of Iron(III) Catecholate Complexes of N,N′-Dimethyl-2,11-diaza[3.3](2,6)pyridinophane (pages 2671–2674)

      Welf O. Koch and Dr. Hans-Jörg Krüger

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526711

      Thumbnail image of graphical abstract

      The reactivity of intradiol-cleaving catechol dioxygenases can be modeled with the complex cation 1. The complex reacts nearly quantitatively with molecular oxygen yielding 3,5-di-tert-butylmuconic anhydride (3) and 3,5-di-tert-butyl-5-carboxymethyl-2-furanone in a 1:1 ratio. The catalytic oxygenation reaction of 2 [Eq. (a)] gives 3 in 70% yield and with a turnover number of 54. dbcH2 = 3,5-di-tert-butylcatechol; L-N4Me2 = N,N′-dimethyl-2,11-diaza[3.3](2,6)pyridinophane.

    16. Assessing Similarity and Diversity of Combinatorial Libraries by Spatial Autocorrelation Functions and Neural Networks (pages 2674–2677)

      Dr. Jens Sadowski, Dr. Markus Wagener and Prof. Dr. Johann Gasteiger

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526741

      Thumbnail image of graphical abstract

      Kohonen neural networks have been used to show that the combinatorial libraries derived from 1 and 2 are very similar, whereas those obtained with 3 are distinctly different. The depicted Kohonen map indicates that the libraries from 1 and 2 are so similar that they need not both be synthesized for screening. R1[BOND]R4: one of 18 possible amino acid residues.

    17. Synthesis of a Cationic 1,3-Diphospha-2,4-dipallada(II)tricyclo[1.1.1]pentane Derivative: The First Structurally Characterized Pyramidal μ2-Phosphinidene (pages 2677–2679)

      Yves Canac, Dr. Antoine Baceiredo, Dr. Heinz Gornitzka, Dr. Dietmar Stalke and Dr. Guy Bertrand

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526771

      Thumbnail image of graphical abstract

      Two pyramidalized μ2-phosphinidene units are present in the cation 1 shown on the right. The complex 1-BFmath image, formed by heating a solution of a diphosphapalladacyclobutene in dichloromethane to reflux in the presence of a diphosphirenium salt, was characterized by an X-ray structure analysis.

    18. Two Diorganopotassates: Crystal Structure of [K(C6H6)][K{C(SiMe3)2(SiMe2Ph)}2] (pages 2679–2680)

      Prof. Colin Eaborn, Dr. Peter B. Hitchcock, Dr. Keith Izod and Dr. J. David Smith

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526791

      The different environments for the two potassium ions in 1 justify its formulation as a potassium salt of a potassate. In an attempt to synthesize the analogous compound containing [C(SiMe3)2{SiMe2(HC[DOUBLE BOND]CH2)}] as anion, crystals of 2 were obtained after four weeks, by the adventitious reaction with silicone grease.

      • equation image
    19. Structure-Determining C[BOND]H…O[BOND]Si Hydrogen Bonds in Cobaltocenium Fluoride Nonasil (pages 2680–2682)

      Prof. Dr. Peter Behrens, Dipl.-Chem. Gianpietro van de Goor and Dr. Clemens C. Freyhardt

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526801

      Thumbnail image of graphical abstract

      Fixed in the SiO2 cage at temperatures below 485 K, the [CoCp2]+ ion in the cobaltocenium fluoride nonasil 1 exhibits no rotational disorder. This unusual structural feature for clathrasils is attributed to strong C[BOND]H…O[BOND]Si interactions, among them hydrogen bonds with a H…O distance of 2.31 Å.

      • equation image
    20. Cascade Radical Reactions of Isonitriles: A Second-Generation Synthesis of (20S)-Camptothecin, Topotecan, Irinotecan, and GI-147211C (pages 2683–2684)

      Prof. Dennis P. Curran, Sung-Bo Ko and Dr. Hubert Josien

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526831

      Thumbnail image of graphical abstract

      Complex molecules can be made in short order, as shown in a concise synthesis of the antitumor agent (20S)-camptothecin (1 with R1 = R2 = H), which relies on a cascade radical reaction [Eq. (a)]. This approach also provides a straightforward route to substituted analogs (R1 = H, Et; R2 = OMe, OH), which are immediate precursors of compounds that have better properties for pharmaceutical applications and are currently in clinical trials.

    21. The Formal Potentials of Solid Metal Hexacyanometalates (pages 2685–2687)

      Prof. Dr. Fritz Scholz and Dipl.-Chem. Aleš Dostal

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526851

      The first report of the formal potentials of a series of solid metal hexacyanometalates (M+)nM′[M″ (CN)6] is given (M+ = Li+, K+, Na+, Rb+, Cs+; M′ = Ag, Al, Cd, Co, Cr, Cu, Fe, Ga, In, Mn, Ni, Pb; M″ = Cr, Fe, Mn). A linear correlation exists between the ionic potential Φ = z/reff of the nitrogen-bonded M′ ions and the formal potentials of the hexacyanometalate ions. This results from increased π back bonding when the acid–base interaction between the nitrogen atom of the cyanide ions and the M′ ions is stronger.

    22. Palladium Complex Catalyzed Asymmetric Allylic Substitutions with Nitromethane: Enantioselectivities Exceeding 99.9%ee (pages 2687–2689)

      Heiko Rieck and Prof. Dr. Günter Helmchen

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526871

      Thumbnail image of graphical abstract

      Small but powerful! Nitromethane serves as a nucleophile in palladium-catalyzed allylic substitutions with allylic carbonates 1 giving nitro compounds 2 with high enantioselectivities. A new mechanism is in action in addition to the known one when R = alkyl; mechanistic details are not yet known.

    23. Transition Metal Complexes as Both Host and Guest: Second-Sphere Coordination between a Pt-Azacrown Ether Host and a Pt-NH3 Guest (pages 2689–2691)

      Dr. Beth R. Cameron, Sonia S. Corrent and Prof. Dr. Stephen J. Loeb

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526891

      Thumbnail image of graphical abstract

      Complexes of the type [PtCl2(PEt3)(azacrown)] can be obtained by the substitution of the ammine ligand in trans-[PtCl2(PEt3)(NH3)] for azacrown ethers. These transition metal containing host molecules form adducts with the cations NHmath image and tBuNHmath image and the neutral complex trans-[PtCl2-(PEt3)(NH3)]. As an X-ray structural study shows, the latter complex is bound to the host by hydrogen bonds (schematic representation shown on the right, R = PtCl2(PEt3)).

    24. A Study on Rhodium – Vinylallene Complexes Leading to a New Reaction, Rhodium-Catalyzed Carbonylative [4 + 1]Cycloaddition (pages 2691–2694)

      Prof. Masahiro Murakami, Kenichiro Itami and Prof. Yoshihiko Ito

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526911

      Thumbnail image of graphical abstract

      Both η2- and η4-coordinated (vinylallene)rhodium(I) complexes can be obtained by ligand exchange with vinylallenes, depending on the substitution at the allene terminus. Vinylallenes like 1 react with CO via η4 complexes in a new RhI-catalyzed [4 + 1]cycloaddition to give cyclopentenones 2.

    25. Distinguishing the Silanol Groups in the Mesoporous Molecular Sieve MCM-41 (pages 2694–2696)

      Prof. Jiesheng Chen, Qinghua Li, Prof. Ruren Xu and Dr. Fengshou Xiao

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526941

      Thumbnail image of graphical abstract

      At least four types of silanol groups are present in MCM-41, a novel silicate with uniform mesopores, according to IR spectroscopy. Isolated silanol groups (type 1 in the picture on the right) and those involved in hydrogen bonds were distinguished by partial silylation with chlorotrimethylsilane (CTMS) and chlorotriphenylsilane (CTPS). Isolated silanol groups are accessible for both CTMS and the bulkier CTPS.

    26. Fluorophosphazenate Ions: A Route to Complexation of Fluoride Ions (pages 2696–2698)

      Dr. Enno Lork, Dr. Dieter Böhler and Prof. Dr. Rüdiger Mews

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526961

      Thumbnail image of graphical abstract

      In the center of the molecule—and thus where it always is for fluorine chemists—sits one of the fluorine atoms of the PF3 unit in the twelvemembered heterocycle P6N6Fmath image (structure shown on the right). However, in the eight-membered ring in the P4N4Fmath image ion, the corresponding fluorine atom interacts with the three other phosphorus centers and forms the apex of a highly distorted square pyramid.

    27. A Novel Class of Versatile Solvents for Two-Phase Catalysis: Hydrogenation, Isomerization, and Hydroformylation of Alkenes Catalyzed by Rhodium Complexes in Liquid 1,3-Dialkylimidazolium Salts (pages 2698–2700)

      Dr. Yves Chauvin, Dr. Lothar Mussmann and Hélène Olivier

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199526981

      Thumbnail image of graphical abstract

      A significant extension of the field of two-phase catalysis is achieved through the use of ionic liquids such as 1. In this way substrates, complexes, and ligands that are poorly soluble or unstable in water can be employed for this industrially important variant of homogeneous catalysis.

    28. Synthesis and Coordination Chemistry of ortho-Functionalized Dimercaptobenzene: Building Blocks for Tripodal Hexathiol Ligands (pages 2700–2703)

      Prof. Dr. F. Ekkehardt Hahn and Dipl.-Chem. Wolfram W. Seidel

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527001

      Thumbnail image of graphical abstract

      The tripodal hexathiol ligand H6−1 is accessible for the first time by coupling 2,3-dimercaptobenzoic acid (2) to 1,3,5-tris(aminomethyl)benzene. The hexadentate ligand H6-1 forms a trinuclear complex with [(C5H5)2 TiCl2] and the complex [Mo(1)] with [Mo(O)2(acac)2].

    29. Ta5(S,Te)2: Microporous Tantalum with Chalcogen-Coated Inner Surfaces (pages 2703–2705)

      Dipl.-Chem. Thomas Degen and Prof. Dr. Bernd Harbrecht

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527031

      Thumbnail image of graphical abstract

      Channels more than 0.6 nm wide run through the tantalum partial structure of Ta5(S,Te)2 (section of structure shown on the right). The microporous structure results from the penetration and linkage of Ta13 icosahedra and icosahedral hypho-Ta11 and arachno-Ta10 fragments. The chalcogen atoms cover the walls of the pores.

    30. Towards the Development of Molecular Wires: Electron Localization, Exchange, and Transfer in Alkyne-Bridged Multinuclear Complexes (pages 2705–2708)

      Vincent Grosshenny, Prof. Anthony Harriman and Dr. Raymond Ziessel

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527051

      Thumbnail image of graphical abstract

      Alkynes are effective promoters of light-induced electron, hole, and energy transfer between metal centers in a multinuclear complex. Studies on ZnII, FeII, and CoII complexes of type 1 led to this and other conclusions.

    31. Butatrienes by Cumuhomologation of Propadienes (pages 2709–2710)

      Prof. Dr. Rolf. W. Saalfrank, Dr. Andreas Welch and Dipl. Chem. Martin Haubner

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527091

      Thumbnail image of graphical abstract

      In only four steps starting from commercially available alkynols, acceptor-substituted butatrienes 1 are accessible in good yields. The key feature of this synthesis is the “cumulation” of the allene function.

    32. New Fluorescent Water-Soluble Taxol Derivatives (pages 2710–2712)

      André A. Souto, Dr. A. Ulises Acuña, José M. Andreu, Dr. Isabel Barasoain, Miguel Abal and Dr. Francisco Amat-Guerri

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527101

      Thumbnail image of graphical abstract

      Biological activity and surprisingly good solubility in water are the properties of the fluorescein-labeled taxol 1 that make visible the attack of the antitumor agent taxol on the microtubule system in cell cultures.

    33. Saccharide–Peptide Hybrids as Novel Oligosaccharide Mimetics (pages 2712–2713)

      Dr. Hans Peter Wessel, Catherine M. Mitchell, Dr. Cinta Maria Lobato and Dr. Gérard Schmid

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527121

      Thumbnail image of graphical abstract

      Block by block the carbohydrate amino acids can be peptidically coupled to form oligosaccharide mimetics, thus providing a simple approach to a novel class of compounds that has great significance for physiological processes. The feasibility of the approach is demonstrated by the block synthesis of tetramer 1.

    34. Synthesis and X-ray Structure of a Shape-Persistent Macrocyclic Amphiphile (pages 2713–2716)

      Dr. Sigurd Höger and Dr. Volker Enkelmann

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527131

      Thumbnail image of graphical abstract

      A rigid molecular framework with hydrophilic and hydrophobic substituents is found in the macrocyclic amphiphile 1, which can be prepared in gram quantities. An X-ray structure determination of crystals of 1 obtained from pyridine shows that the polar phenoxy groups point toward the outside and that the macrocycle has a hydrophobic interior.

    35. Structure and Magnetic Properties of a Decanuclear Oxoiron(III) Cluster: A Further Step to Understanding Iron Aggregation Processes (pages 2716–2718)

      Dr. Andrea Caneschi, Dr. Andrea Cornia, Prof. Antonio C. Fabretti and Prof. Dante Gatteschi

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527161

      Thumbnail image of graphical abstract

      Parallel layers of Fe and O atoms are found in the core of the decairon(III) complex 1 (dbm = dibenzoylmethane) (structure shown on the right), which is prepared by controlled hydrolysis of FeCl3. The O atoms in 1 display the same cubic closest packing arrangement as that found in some iron oxides and hydroxides. The layered arrangement of iron ions may suggest a possible mechanism for the growth of bulk oxides from smaller aggregates

      • equation image
    36. “Fast Amide Cleavage” or Reproducible, Concentration- and Time-Dependent Aggregation of Anionic and Cationic Surfactants? (pages 2718–2720)

      Prof. Wilmer K. Fife and Dr. Shanghao Liu

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527181

      Thumbnail image of graphical abstract

      Mixtures of a cationic surfactant containing an activated amide function and the anionic surfactant hexadecanoate ion in aqueous buffer at pH 8 and 25.0 °C produce anion–cation aggregates rather than the “fast amide cleavage under mild conditions” reported by Menger et al. last year in Angewandte Chemie.

    37. A Strategy of “Random Glycosylation” for the Production of Oligosaccharide Libraries (pages 2720–2722)

      Osamu Kanie, Frank Barresi, Yili Ding, Jill Labbe, Albin Otter, L. Scott Forsberg, Dr. Beat Ernst and Prof. Ole Hindsgaul

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527201

      Six at one blow! The creation of small oligosaccharide libraries was achieved by a new strategy of random glycosylation of nonprotected sugars. With tri-O-benzyl-L-fucopyranosyl trichloroacetimidate as donor and βGal(1 [RIGHTWARDS ARROW] n)βGlcNAc[BOND]OR (n = 3, 4, 6; R = (CH2)8OC6H4-p-OMe) as acceptors, all six trisaccharides form in DMF in roughly equal quantities. It is astounding that all free OH groups are fucosylated at a similar rate.

    38. A New Nickel-Catalyzed Cross-Coupling Reaction between sp3 Carbon Centers (pages 2723–2725)

      Dr. Arokiasamy Devasagayaraj, Dipl.-Chem. Thomas Stüdemann and Prof. Dr. Paul Knochel

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527231

      Thumbnail image of graphical abstract

      Polyfunctional dialkylzinc compounds and primary alkyl iodides bearing a remote double bond undergo nickel-catalyzed cross-coupling even at −35 °C within a few hours, as shown in the example below. The resulting polyfunctional products are formed in good yield. NMP = N-methyl-2-pyrrolidinone, acac = acetylacetonate, Piv = pivaloyl.

    39. Water-Soluble Dendritic Iron Porphyrins: Synthetic Models of Globular Heme Proteins (pages 2725–2728)

      Dr. Peter J. Dandliker, Prof. François Diederich, Dr. Jean-Paul Gisselbrecht, Dr. Alain Louati and Prof. Maurice Gross

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527251

      Thumbnail image of graphical abstract

      The redox behavior is markedly different for the second generation dendrimer 1 (depicted on the right) from that of the first generation dendrimer without the densely packed dendritic structure. The unusually positive FeIII/FeII redox potential of 1 in water (+0.19 V vs. SCE) is attributable to the strong shielding of the heme core from the surrounding solvent by the dendritic environment.

    40. A New Strategy in Heterogeneous Catalysis: The Design of Cortex Catalysts (pages 2728–2730)

      Prof. Dr. Manfred T. Reetz, Dr. Stefan A. Quaiser, Dipl.-Ing. Rolf Breinbauer and Dr. Bernd Tesche

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527281

      Thumbnail image of graphical abstract

      Without appreciable migration into the pores of the support (Al2O3), preformed and size-selectively synthesized metal clusters (e.g. Pd or Ni) and bimetal clusters (e.g. Pt/Sn) stabilized by ammonium salts can be placed specifically on the outer surface and immobilized (see schematic representation on the right; black: metal cluster, gray: support particles). Initial experiments indicate that such cortex catalysts show increased activities in hydrogenation reactions.

    41. 1-Phenyl-1,2-cyclooctadiene Dimerizes in an Unusual Manner (pages 2730–2732)

      Prof. Dr. Manfred Christl, Dipl.-Chem. Marcus Rudolph, Eva-Maria Peters, Karl Peters and Prof. Dr. Hans Georg von Schnering

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527301

      Thumbnail image of graphical abstract

      Under kinetic control, the dimerization of the title allene proceeds with participation of one phenyl group. Only on thermolysis of the dimer 1 is the thermodynamically favored dimer 2 formed, which, unlike the dimers of known cycloallenes with eight-membered or smaller rings, has a cis configuration.

  4. Book Reviews

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Book Reviews
    6. Author Index
    7. Subject Index
    1. New Books (Angew. Chem. Int. Ed. Engl. 23/24/1995) (page 2733)

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527331

  5. Author Index

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Book Reviews
    6. Author Index
    7. Subject Index
    1. Author Index [Angrew. Chem. Int. Ed. Engl. 1995, 34] (pages 2745–2755)

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199527451

  6. Subject Index

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Book Reviews
    6. Author Index
    7. Subject Index

SEARCH

SEARCH BY CITATION