Angewandte Chemie International Edition in English

Cover image for Vol. 35 Issue 5

March 4, 1996

Volume 35, Issue 5

Pages 467–555

Currently known as: Angewandte Chemie International Edition

    1. Cover Picture (Angew. Chem. Int. Ed. Engl. 5/1996)

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199604651

      Thumbnail image of graphical abstract

      The cover picture shows the structure of the subnitride Na14Ba14CaN6. Ion clusters (blue) of the composition Ba8CaN6 with a perowskitelike arrangement of atoms—Ca-centered Ba8 cubes surrounded by N atoms above all faces—are dispersed in a metallic matrix (red) of sodium and barium. More about this compound, which can be considered a salt dissolved in a metal, is reported by U. Steinbrenner and A. Simon on p. 552 ff.

  1. Editorial

    1. Top of page
    2. Editorial
    3. Reviews
    4. Highlights
    5. Communications
    6. Corrigenda
    7. Book Reviews
    1. You have free access to this content
      EDITORIAL (pages 467–468)

      Peter Gölitz

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199604671

    1. Graphical Abstract (Angew. Chem. Int. Ed. Engl. 5/1996) (pages 467–472)

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199604672

  2. Reviews

    1. Top of page
    2. Editorial
    3. Reviews
    4. Highlights
    5. Communications
    6. Corrigenda
    7. Book Reviews
    1. The Schenck Ene Reaction: Diastereoselective Oxyfunctionalization with Singlet Oxygen in Synthetic Applications (pages 477–494)

      Dr. Michael Prein and Prof. Dr. Waldemar Adam

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199604771

      Thumbnail image of graphical abstract

      The obstinate singlet oxygen can be tamed by a number of factors: steric, stereoelectronic, electronic, and conformational effects of the functional group X play an important role in controlling the direction of the attack of singlet oxygen on alkenes [Eq. (a)]. This unfortunately rarely employed reaction, the Schenck ene reaction, yields diastereoselectively oxyfunctionalized compounds—useful intermediates in organic synthesis. X = hydroxyl, amino, halogen, ether, ester, sulfoxide, sulfone.

    2. Electron Domains and the VSEPR Model of Molecular Geometry (pages 495–514)

      Prof. Ronald J. Gillespie and Prof. Edward A. Robinson

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199604951

      Simpler to apply than the original model and supported by the analysis of electron density distributions with the Laplacian operator, the reformulation of the VSEPR model of molecular geometry presented here is based on the concept of electron domains. In this form it is suitable as foundation for a qualitative understanding of the geometry of a large number of molecules, including those of metal compounds. Analyses of the valence and core electron densities with the Laplacian operator often also yield plausible explanations why some molecules do not have the structure predicted by the VSEPR model.

  3. Highlights

    1. Top of page
    2. Editorial
    3. Reviews
    4. Highlights
    5. Communications
    6. Corrigenda
    7. Book Reviews
    1. Voids in Variable Chemical Surroundings: Mesoporous Metal Oxides (pages 515–518)

      Prof. Dr. Peter Behrens

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605151

      Structural design in the synthesis of solids is now a step closer, at least for mesoporous compounds. Surfactant assemblies are used as templates to structure metal oxides, which are formed from metal alkoxides. By adapting the headgroup of the surfactant to the inorganic component and exploiting the coordination chemistry of the metal atoms in the alkoxides, a wide range of mesoporous metal oxides, including alumina, titania, niobia, and zirconia, becomes available.

    2. The “Magic” Diarylhydroxymethyl Group (pages 519–522)

      Prof. Dr. Manfred Braun

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605191

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      Increasing stereoselectivity in numerous recently developed methods of asymmetric synthesis is possible with the diarylhydroxymethyl group, which is typically employed in deprotonated form as a ligand in metal complexes. In the transition state of these reactions the geminal aryl groups are apparently fixed in a chiral conformation owing to the influence of a permanent stereogenic center X*. A schematic representation of this type of metal catalyst is shown on the right.

  4. Communications

    1. Top of page
    2. Editorial
    3. Reviews
    4. Highlights
    5. Communications
    6. Corrigenda
    7. Book Reviews
    1. Pyridinium Ions Adjacent to Oxirane Rings: Useful Intermediates for the Stereospecific Synthesis of β-Hydroxy Ketones (pages 523–524)

      Dr. Yousef Al-Abed, Noshena Naz, Dr. Khalid Mohammed Khan and Prof. Dr. Wolfgang Voelter

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605231

      Thumbnail image of graphical abstract

      α,β-Epoxytriflates like epoxytriflate pyranoside 1 undergo rearrangement in a one-pot reaction after treatment with pyridine. The epoxy ring is opened giving N-vinylpyridinium derivatives such as 2, which can be reduced with NaBH4 and hydrolyzed under acidic conditions to give β-hydroxy ketones. This generally applicable procedure can be used to convert easily accessible epoxypyranoses into deoxyketo sugars like 3 in high yields.

    2. New Cobalt Catalysts for Hydroformylations in Two-Phase Systems (pages 524–526)

      Dr. Uwe Ritter, Dr. Norbert Winkhofer, Hans-Georg Schmidt and Prof. Dr. Herbert W. Roesky

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605241

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      Not water, but polyethyleneglycol serves as the solvent for the cobalt complex 1 (R [DOUBLE BOND] CH2CH2(OCH2CH2)nOH, n = 9), an efficient catalyst for the hydroformylation of 1-hexene. Because complex 1 is not soluble in unpolar solvents, this highly chemoselective reaction can be conducted in the two-phase system polyethyleneglycol/hexene.

    3. The First closo-Monosilaborane (page 527)

      Dr. Lars Wesemann and Dr. Ulli Englert

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605271

      Thumbnail image of graphical abstract

      A cluster construction reaction starting with silaborane 1 and triethylamine–borane provides 1-methyl-1-sila-closo-dodecaborate(1−) 2 in 93% yield.

    4. Bis(lithiomethyl) Sulfide, An Unexpectedly Stable 1,3-Dilithiated Synthetic Building Block (pages 528–529)

      Dr. Carsten Strohmann

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605281

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      Although extremely useful, only a few 1,3-dilithiated organoelement compounds are known, because no suitable synthetic methods were available. Now bis(lithiomethyl) sulfide (2) has been prepared by double metal-lithium exchange (transmetalation) from 1 and 3. At room temperature 2 is a colorless metastable powder.

    5. Trapping and Imaging Molecular Dynamics by Combining Scanning Force Microscopy with Topology (pages 529–530)

      Prof. Bruno Samori, Dr. Carmelo Nigro, Amalia Gordano, Dr. Innocenzo Muzzalupo and Dr. Carla Quagliariello

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605291

      Thumbnail image of graphical abstract

      Transient detachments and even minor movements of chain segments of a single DNA molecule adsorbed on a substrate can be revealed by the method described in this communication. The scanning force microscopy image on the right shows a DNA molecule on mica with an open circular shape acquired after extensive detachments and movements.

    6. Programmed Self-Assembly of Copper(II)-L- and -D-Arginine Complexes with Aromatic Dicarboxylates to Form Chiral Double-Helical Structures (pages 531–532)

      Nayumi Ohata, Dr. Hideki Masuda and Prof. Dr. Osamu Yamauchi

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605311

      Thumbnail image of graphical abstract

      The dianion is the key! Complexes of the type [Cu(Arg)2](L)·nH20 (L = aromatic dicarboxylate, n = 5,6) formed by self-assembly show double-helical structures in the solid state, which comprise infinite [Cu(Arg)2]2+-L2− strands (shown schematically below). In these, the dianions function as bridging ligands, bound through guanidinium–carboxylate pairs, between the complex cations and read the information of handedness coded in the [Cu(Arg)2]2+ units.

    7. Methyltrioxorhenium(VII)-Catalyzed Epoxidation of Alkenes with the Urea/Hydrogen Peroxide Adduct (pages 533–535)

      Prof. Dr. Waldemar Adam and Dipl.-Chem. Catherine M. Mitchell

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605331

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      High yields and only traces of side products are possible in the synthesis of epoxides by oxidation of alkenes when the urea/hydrogen peroxide adduct (UHP) is used as the oxygen donor in the methyltrioxorhenium(VII)-catalyzed reaction (see below). Chiral allylic alcohols with 1,3-strain were employed as stereochemical probes; the high threo diastereoselectivities obtained allow important mechanistic insights into the oxygen transfer process.

    8. Diastereoselective Chelation-Controlled Radical Cyclization of Chiral Oxazolidinone-Derived 2-Alkenamides and Modeling of the Transition State (pages 535–538)

      Dr. Domenico Badone, Dr. Jean-Marie Bernassau, Dr. Rosanna Cardamone and Dr. Umberto Guzzi

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605351

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      A good yield, but only modest diastereoselectivity (2:3 = 45:55) is achieved in the radical cyclization of 1 to give 2 and 3. MgBr2·Et2O was essential for good diastereoselectivity (2:3 = 82:18). Transition state modeling with a specifically developed “radical force-field” suggested that the observed diastereoselectivities can be ascribed to van der Waals attractive interactions between arenes.

    9. Synthesis and NLO Properties of Polar Self-Assemblies of Molecular Pyramids Covalently Bound on Oxide Surfaces (pages 538–540)

      Dr. Xiaoguang Yang, Dr. Duncan McBranch, Dr. Basil Swanson and Dr. DeQuan Li

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605381

      Thumbnail image of graphical abstract

      Ultrahigh second-order nonlinearities were observed in calix[4]arene-based, chromophoric super-molecules, which form densely packed, highly ordered monolayers on silica surfaces (shown on the right). The super chromophores consist of four stilbazole-imine units in a rigid cone conformation, in which all the dipoles are aligned in the same direction.

    10. Formation of a Porous Zirconium Oxo Phosphate with a High Surface Area by a Surfactant-Assisted Synthesis (pages 541–543)

      Dipl.-Chem. Ulrike Ciesla, Dipl.-Chem. Stefan Schacht, Prof. Dr. Galen D. Stucky, Prof. Dr. Klaus K. Unger and Prof. Dr. Ferdi Schüth

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605411

      Thumbnail image of graphical abstract

      Analogous to the synthesis of MCM-41, a mesostructured product (shown schematically on the right) can be obtained from aqueous solutions of zirconium sulfate by addition of alkyltrimethylammonium salts. After a treatment with phosphoric acid, this material can be calcined without structural collapse. The resulting zirconium oxo phosphate shows BET surface areas of up to 400 m2 g−1.

    11. Generation of a Heterocyclic 1,3-Cyclopentanediyl Radical Cation by Chemically Induced Electron Transfer Oxidation and Pulse Radiolysis (pages 543–545)

      Prof. Dr. Waldemar Adam, Dipl.-Chem. Thomas Kammel and Prof. Dr. Steen Steenken

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605431

      Thumbnail image of graphical abstract

      Instead of the 1,2-alkyl migration well-established for carbocyclic analogues, the 1,3-radical cation 1˙+, generated from the corresponding housane 1 by oxidation with (4-BrC6H4)3N˙+SbClmath image, undergoes an unexpected deprotonation to give the monoradical (1[BOND]H)˙. In this process the proton is presumably transferred to one of the two carbonyl groups of the triazolidinedione ring.

    12. Sibyllimycine, 5,6,7,8-Tetrahydro-3-methyl-8-oxo-4-azaindolizidine, a Novel Metabolite from Thermoactinomyces sp. (pages 545–547)

      Dipl.-Biol. Doris Hafenbradl, Dr. Martin Keller, Prof. Dr. Karl O. Stetter, Priv.-Doz. Dr. Peter Hammann, Dipl.-Ing. Frank Hoyer and Dr. Herbert Kogler

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605451

      Thumbnail image of graphical abstract

      The first natural product of its structure type, azaindolizidine 1 was produced by fermentation of an isolate of thermophilic actinomyces obtained from a 60°C hot spring at Lake Tanganyika (Africa). The structure of this compound was determined from NMR data and verified by synthesis from methylimidazole and 4-bromobutyronitrile.

    13. Phosphaalkyne Hydrometalation: Synthesis of [RuCl(P[DOUBLE BOND]CHtBu)(CO)(PPH3)2] (pages 547–549)

      Dr. Robin B. Bedford, Dr. Anthony F. Hill and Dr. Cameron Jones

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605471

      Thumbnail image of graphical abstract

      An unprecendently simple metallaphosphaalkene, which can be readily and reversibly protonated to provide a complex of the otherwise unstable phosphaalkene HP[DOUBLE BOND]CHtBu, is the product of the first hydrometalation of phosphaalkynes [Eq. (a); [Ru] [DOUBLE BOND] RuCl(CO)(PPh3)2, R [DOUBLE BOND] tBu].

    14. Synthesis of a “Molecular Pinwheel”: [3.3.3.3.3.3](1,2,3,4,5,6)Cyclophane (pages 549–550)

      Youichi Sakamoto, Naomi Miyoshi and Prof. Dr. Teruo Shinmyozu

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605491

      Thumbnail image of graphical abstract

      Six trimethylene bridges link the phenyl rings of the “pinwheel” compound 1, which was synthesized from [35](1,2,3,4,5)cyclophane. An intramolecular aldol condensation serves as the key step for introducing the final trimethylene bridge. The NMR spectroscopic data suggest a highly symmetrical and dynamic structure for 1.

    15. Synthesis and Structure of a Digallane with Tris(trimethylsilyl)silyl and Chloro Substituents (pages 550–552)

      Dr. Gerald Linti and Dipl.-Chem. Wolfgang Köstler

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605501

      Thumbnail image of graphical abstract

      A cage comprising four gallium and four chlorine atoms (shown on the right) is the characteristic feature of the first dimeric digallane 1 (R = Si(SiMe3)3) having two different substituents. It is synthesized together with the tetrasilyl-substituted digallane 2 from Ga[GaCl4] and LiSi(SiMe3)3(THF)3.

    16. Na14Ba14CaN6—A Nanodispersion of a Salt in a Metal (pages 552–554)

      Dipl.-Chem. Ulrich Steinbrenner and Prof. Dr. Arndt Simon

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605521

      Thumbnail image of graphical abstract

      The new cluster Ba14CaN6, whose core Ba8CaN6 is a fragment of the perowskite structure type, is contained in the title subnitride. The structure of Na14Ba14CaN6 (pictured on the right) represents a “nanodisperse” system of saltlike particles in a metallic matrix.

  5. Corrigenda

    1. Top of page
    2. Editorial
    3. Reviews
    4. Highlights
    5. Communications
    6. Corrigenda
    7. Book Reviews
    1. You have free access to this content
      Corrigendum (page 554)

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199605541

  6. Book Reviews

    1. Top of page
    2. Editorial
    3. Reviews
    4. Highlights
    5. Communications
    6. Corrigenda
    7. Book Reviews

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