Angewandte Chemie International Edition in English

Cover image for Vol. 33 Issue 19

October 17, 1994

Volume 33, Issue 19

Pages 1897–1994

Currently known as: Angewandte Chemie International Edition

    1. Cover Picture (Angew. Chem. Int. Ed. Engl. 19/1994)

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199418951

      Thumbnail image of graphical abstract

      The cover picture shows a ball-and-stick model of the first peroxocopper(II) complex [(Cu4L2)(O2)(OMe)2(ClO4)]+ (L = anion of the tridentate ligand 4-methyl-2,6-bis-(pyrrolidinomethyl)phenol) stable at room temperature. This cation (color code: Cu brown, O red, N blue, C black, Cl green) is characterized by several unusual structural details, including a μ4-bridging O2 ligand and a ClO4 ligand bound unsymmetrically to the Cu4 center. The picture was produced with the program POV-Ray on a IBM Workstation by Dipl.-Chem. S. J. Schindler, Further information on the structural and spectroscopic properties of this compound, which are of general interest for biochemistry and coordination chemistry, are reported by B. Krebs and J. Reimm on pages 1969ff.

  1. Reviews

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Corrigenda
    6. Book Reviews
    7. New Books
    1. Prostacyclin and Thromboxane Synthase: New Aspects of Hemethiolate Catalysis (pages 1911–1919)

      Prof. Dr. Volker Ullrich and Roland Brugger

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419111

      Thumbnail image of graphical abstract

      Homolytic O[BOND]O bond cleavage, rearrangement of the oxygen radical to form a carbon radical, and oxidation of the carbon radical are postulated as common features of hemethiolate-catalyzed reactions. This mechanism was deduced from studies on the mode of action of the two isomerases that generate prostacyclin (PGI2) and thromboxane (TxA2) from epidioxyprostaglandin (PGH2).

    2. Toxicity of Chlorinated Organic Compounds: Effects of the Introduction of Chlorine in Organic Molecules (pages 1920–1935)

      Prof. Dr. Dietrich Henschler

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419201

      Chlorine chemistry—a controversial subject! Why is that so? Polychlorinated compounds are, for example, frequently very stable and accumulate in the environment and in the food chain; numerous chlorinated compounds of different kinds are mutagenic and carcinogenic: “Abolition” of chlorine chemistry is of course not practical even when this has been demanded repeatedly for years. The present systematic analysis elaborates recommendations for the reduction and avoidance of risk during production, occupational handling, and general use of chlorinated alkanes, alkenes, alkynes, as well as benzene and phenol derivatives.

  2. Highlights

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Corrigenda
    6. Book Reviews
    7. New Books
    1. Bolaamphiphiles: From Golf Balls to Fibers (pages 1937–1940)

      Gregory H. Escamilla and Prof. George R. Newkome

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419371

      Molecular structures can perform diverse functions. Tailored bolaamphiphiles were used to prepare vesicles containing redox-active centers or (chiral) binding sites for guests, as well as aggregates. In addition, monomeric and polymeric bolaamphiphiles can disrupt membranes. RNA-based bolaamphiphiles of this type may also find application in biochemistry as antisense agents.

    2. Molecules and Ions with Heptacoordinated Central Atoms (pages 1941–1942)

      Prof. Dr. Rolf Minkwitz

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419411

      Not the energy-minimum structures predicted by VSEPR theory, namely a capped octahedron with C2, or a capped prism with C3, symmetry, but a pentagonal-bipyramidal structure with D5h symmetry, which, however, is highly fluxional, are observed for molecules and ions with a heptacoordinated central atom. These results were obtained from recent studies by Christe et al., Seppelt et al., and Cockcroft et al; the latter recently determined the structure of ReF7 by high-resolution powder neutron diffraction.

  3. Communications

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Corrigenda
    6. Book Reviews
    7. New Books
    1. Rb3[Nb6SBr17], the First Compound Containing an Isolated Trigonal-Prismatic Niobium Cluster (pages 1943–1944)

      Dipl.-Chem. Hermann Womelsdorf and Priv.-Doz. Dr. H.-Jürgen Meyer

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419431

      Thumbnail image of graphical abstract

      The novel trigonal-prismatic niobium cluster in the [Nb6SBr18]4− unit (shown on the right) contains a S atom (white sphere) in its center, and is linked through bromine atoms to form infinite chains. In this system the two Nb3 triangles (black spheres) are held together by strong Nb[BOND]S and weak Nb[BOND]Nb bonds.

    2. O-Glycoside Syntheses under Neutral Conditions in Concentrated Solutions of LiClO4 in Organic Solvents (pages 1944–1946)

      Prof. Dr. Herbert Waldmann, Dipl.-Chem. Gerd Böhm, Dipl.-Chem. Uschi Schmid and Dr. Herbert Röttele

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419441

      Under mild, neutral conditions syntheses of O-glycosides are possible when the glycosyl donor is treated with a glycosyl acceptor in 1 M solutions of LiClO4 in organic solvents. The vital difference between this and the usual processes is that no promoters like heavy metal salts, alkylating agents, and strong Lewis acids are needed.

    3. Doubly Bridged rac-Metallocenes of Zirconium and Hafnium (pages 1946–1949)

      Prof. Dr. Wolfgang A. Herrmann, Marcus J. A. Morawietz and Thomas Priermeier

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419461

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      A quantitative and stereoselective synthesis of rac-metallocenes has been developed for the first time. The novel rac-metallocenes 1 were obtained from readily accessible homoleptic metal amides and nondeprotonated cyclopentadienes. Complexes of this type can be considered as catalysts of isotactic olefin polymerization. M = Zr, Hf; Y = NPh, C5H4.

    4. Iron-Promoted, Regio- and Stereoselective Allylic Substitutions for the Synthesis of Alkenyl Sulfones Substituted at C-3 (pages 1949–1951)

      Prof. Dr. Dieter Enders, Dipl.-Chem. Bernd Jandeleit and Dr. Gerhard Raabe

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419491

      Thumbnail image of graphical abstract

      Almost complete transfer of chirality is observed in the nucleophilic addition of various carbon and nitrogen nucleophiles (Nu) to the highly enantiomerically enriched 1-phenylsulfonyl-substituted (η3-allyl)tetracarbonyliron(1+) tetrafluoroborate with planar chirality (1; de, ee > 98%). Oxidative decomplexation yields alkenyl phenyl sulfones 2 with a range of subtituents at C-3 and high enantiomeric purity (ee ≥ 96%).

    5. α-Aryliodonio Diazo Compounds: SN Reactions at the α-C Atom as a Novel Reaction Type for Diazo Compounds (pages 1952–1953)

      Prof. Dr. Robert Weiss, Dipl.-Chem. Jörg Seubert and Dr. Frank Hampel

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419521

      Thumbnail image of graphical abstract

      α-Onio-substituted diazo compounds 2 are formed by reaction of nucleophiles Nu with α-aryliodonio diazo compounds such as 1. These are the first SN reactions at the α-C atom of diazo compounds that proceed with retention of the diazo function. Nu = pyridine, SMe2, AsPh3, SbPh3, NEt3.

    6. Diastereoselective Reaction of a 1-Phosphaallyl Anion with an Alkyne: Structure of an Isolated Dihydrophospholyl Anion and Stereospecific Protonation to Give 2,3-Dihydrophosphole (pages 1953–1955)

      Prof. Dr. Edgar Niecke, Dr. Martin Nieger and Dipl.-Chem. Peter Wenderoth

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419531

      Thumbnail image of graphical abstract

      A noncomplexed allyl anion fragment forms part of the dihydrophospholyl anion 2 which is obtained from the polar 1,3-cycloaddition of the 1-phosphaallyl anion 1 to diphenylacetylene. The crystal structure of 2 was determined. The protonation of 2 leads to the 2,3-dihydrophosphole 3 in a regio- and stereoselective reaction.

    7. Cyclopropanation by Methylene Transfer from (η2-Formaldehyde)zirconocene Complexes (pages 1955–1957)

      Prof. Dr. Gerhard Erker, Dr. Stefanie Schmuck and Dr. Maximilian Bendix

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419551

      Thumbnail image of graphical abstract

      Reminiscent of the chemistry of methylene on metal oxide surfaces, the cyclopropanation of the (formaldehyde)zirconocene dimer 1 with the alkenyl complexes 2 leads to the cyclopropyl complexes 4. The intermediates 3 were characterized by NMR spectroscopy. This reaction might contribute to the understanding of reactions on the metal oxide surfaces of heterogeneous catalysts.

    8. 2,2′-Bipyrenyl and para-Terpyrenyl—A New Type of Electronically Decoupled Oligoarylene (pages 1957–1959)

      Dipl.-Chem. Martin Kreyenschmidt, Dr. Martin Baumgarten, Prof. Dr. Nikolay Tyutyulkov and Prof. Dr. Klaus Müllen

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419571

      Thumbnail image of graphical abstract

      By bridging over centers that lie in nodal planes of the frontier orbitals, the electronic decoupling of the pyrene units in the new compounds bipyrenyl 1 and para-terpyrenyl 2 is achieved. This causes the electronic situation to differ fundamentally from that in biphenyl, oligo(para-phenylene)s, and related oligoarylenes. R is, for example, n-pentyl.

    9. Ring Closures on Polymeric Supports—Formation of Extremely Large Macrocycles by Intrapolymeric Cyclooligomerizations (pages 1960–1961)

      Prof. Dr. Manfred Rothe, Dipl.-Chem. Manfred Lohmüller, Dr. Ulrich Breuksch and Dr. Günter Schmidtberg

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419601

      Extremely large rings with up to several hundred ring atoms are obtained by cyclooligomerization of polymer-bound linear molecules, for example cyclic oligoamides of ϵ-aminohexanoic acid with up to 280 ring atoms. Thus weakly crosslinked polymeric supports do not enforce steric isolation of covalently bound bifunctional molecules, as previously reported. Instead intrapolymer reactions with subsequent ring closure dominate.

    10. The First Spectroscopic Identification of an Enol Radical Cation in Solution: The Anisyl-dimesitylethenol Radical Cation (pages 1961–1963)

      Prof. Dr. Michael Schmittel, Dr. Georg Gescheidt and Dipl.-Chem. Maik Röck

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419611

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      Deprotonation is the preferred reaction path for enol radical cations. This was shown by the characterization of the enol radical cation 1 in solution by ESR and ENDOR spectroscopy, cyclic voltammetric investigations, and measurement of the kinetic isotope effect. The mechanism of action of ribonucleotide reductase and diol dehydratase, which was formulated as nucleophilic attacks on enol radical cations, must therefore be reconsidered.

    11. Matrix Spectroscopy of 2-Adamantylidene, a Dialkylcarbene with Singlet Ground State (pages 1964–1966)

      Prof. Thomas Bally, Dipl.-Chem. Stephan Matzinger, Leo Truttmann, Prof. Matthew S. Platz and Dr. Scott Morgan

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419641

      Thumbnail image of graphical abstract

      A broad band at λmax ≈ 620 mm confirms the singlet character of the carbene 1, since no other conceivable compounds in the system should absorb in this region. Moreover, calculations on dialkylcarbenes yield similar λ values. Compound 1 rearranges photochemically to 2, and on warming in a CO-doped argon matrix it affords 3.

    12. 3,3′-Bis(dicyanomethylene)-4,4,4′,4′-tetramethyl-2,2′-bithiolanylidene, a Compound Containing the Fundamental Chromophore of Thioindigo: (E/Z) and Valence Isomers, Thermo- and Photochromism (pages 1966–1969)

      Dipl.-Chem. Andreas Pawlik, Priv.-Doz. Dr. Walter Grahn, Dipl.-Chem. Axel Reisner, Prof. Dr. Peter G. Jones and Prof. Dr. Ludger Ernst

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419661

      Thumbnail image of graphical abstract

      The first dicyanomethylene analogue 1 [(E/Z) mixture] of a compound containing the fundamental chromophore of thioindigo can be converted consecutively into the valence isomers 2,3, and 4. The two new photochromic systems found (2/1 and 3/4), which are based on the hexatriene/cyclohexadiene conversion, may be of interest for optical information technology.

    13. A Thermally Stable Peroxocopper(II) Complex with Unusual μ4-Coordination of the Peroxo Ligand (pages 1969–1971)

      Dipl.-Chem. Jörg Reim and Prof. Dr. Bernt Krebs

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419691

      Thumbnail image of graphical abstract

      Stable at room temperature, the peroxocopper(II) cation in 1 (HL = 4-methyl-2,6-bis(pyrrolidinomethyl)phenol) is a tetranuclear complex (the picture shows the central unit) that displays several unusual structural details, including a μ4-bridging peroxo ligand. Peroxocopper(II) complexes are, in general, unstable compounds that can often be characterized only by spectroscopic methods at low temperatures. • equals; Cu, ○ = O,

      = N.

      • equation image
    14. Regio- and Diastereoselective Photooxygenation of Chiral 2,5-Cyclohexadiene-l-carboxylic Acids (pages 1971–1972)

      Dr. Torsten Linker and Lothar Fröhlich

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419711

      Thumbnail image of graphical abstract

      Diastereoselectivities greater than 96% were achieved in the singlet oxygen ene reaction of the cyclohexadiene carboxylic acids 1. The hydroperoxides 2 and 3 were obtained in excellent yields and constitute valuable building blocks for organic synthesis. The stereoselectivities can be influenced by varying the substituents R and the reaction conditions. R = Me, Et, iPr.

    15. Tris(η4-naphthalene)zirconate(2−) (pages 1973–1975)

      Dr. Meehae Jang and Prof. Dr. John E. Ellis

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419731

      Thumbnail image of graphical abstract

      Highly reactive, thermally stable, and air sensitive are three characteristics of the dark red title compound 1, which was prepared from ZrCl4·2 THF and potassium naphthalenide. The three naphthalene ligands are bound η4 to the Zr center and the co-ordination environment has approximate C3v, local symmetry (shown on the right). Compound 1 is the first tris(naphthalene) complex and the first structurally characterized homoleptic naphthalene metalate.

    16. An Anthracene-Based Fluorescent Sensor for Transition Metal Ions (pages 1975–1977)

      Prof. Dr. Luigi Fabbrizzi, Dr. Maurizio Licchelli, Dr. Piersandro Pallavicini, Prof. Dr. Angelo Perotti and Dr. Donatella Sacchi

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419751

      Thumbnail image of graphical abstract

      Recognition of cations by fluorescence quenching or enhancement has previously been limited to d0 and d10 cations. The fluorescent sensor 1 recognizes CuII and NiII ions in a pH-controlled complexation, in which the amide groups are deprotonated and the fluorescence of the anthracene group is quenched. ZnII and other divalent ions earlier in the 3d series (e.g. MnII and CoII) are not recognized by 1. Since only CuII is chelated by 1 at pH 7, CuII and NiII can be distinguished.

    17. Benzobis(thiadiazole)s Containing Hypervalent Sulfur Atoms: Novel Heterocycles with High Electron Affinity and Short Intermolecular Contacts between Heteroatoms (pages 1977–1979)

      Katsuhiko Ono, Dr. Shoji Tanaka and Prof. Dr. Yoshiro Yamashita

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419771

      Thumbnail image of graphical abstract

      Ribbon-type columns linked to form a network are found in the crystal structure of 1, R = Br. This compound differs significantly from the Kekulé-type analogue 2 in terms of its electron affinity and the position of its UV/VIS absorption maximum. The monoselenium analogues of 1 were also synthesized and characterized.

    18. Stereoselective Intramolecular Alkylation of Glycosylimides to Highly Functionalized Bicyclic 2,5-Azepanediones and Heterotricyclic [5.3.1.02, 6]undecanamides (pages 1979–1981)

      Dipl.-Chem. Carsten Endres Sowa and Prof. Dr. Joachim Thiem

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419791

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      An intramolecular, stereoselective alkylation for monosaccharides is obtained by irradiation of glycosylimides with UV light. The regiochemistry of the central Norrish type II hydrogen abstraction can be controlled by the choice of saccharides and protecting groups. In this way the bicyclic and tricyclic compounds 1 and 2, respectively, become accessible. R = tBuMe2Si.

    19. Homoleptic Thiolato Complexes: Di- and Trinuclear TiIV Complexes with Unexpected Metal–Sulfur Cores, [NMe2H2][Ti2(SMe)9] and [Ti3(SMe)12] (pages 1981–1983)

      Wolfram Stüer, Dr. Kristin Kirschbaum and Dr. Dean M. Giolando

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419811

      Thumbnail image of graphical abstract

      Despite terminal thiolato ligands, none of the titanium centers in complexes 1 and 2 have a coordination geometry close to the expected Oh symmetry. In 1 (counterion: [NMe2H2]+) the coordination polyhedra of the metal atoms are trigonally twisted to the mid-point of the Oh [RIGHTWARDS ARROW] D3h reaction coordinate by about 32°; in 2 the coordination polyhedron of the central Ti atom is so severely twisted that it approaches D3h symmetry. • = SMe.

    20. The First Structurally Characterized Metal Complex Involving the Free Acid of a New Tris(pyrazolyl)borate as Ligand (pages 1983–1985)

      Prof. Dr. Arnold L. Rheingold, Brian S. Haggerty and Dr. Swiatoslaw Trofimenko

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419831

      Thumbnail image of graphical abstract

      One of the three pyrazolyl groups of the scorpionato ligand occurs in the protonated form in the bright orange Cu complex [(TpCy)HCuCl2] (1) and forms a hydrogen bond with a Cu-bound Cl atom. In the reaction of [TpCyTl] with CuCl2ṁ2H2O. 1 is formed rather than the expected complex [TpCyMCl] (TpCy = [HB(cyclohexylpyrazolyl)3], R = Cy = cyclohexyl).

    21. The SRN2 Pathway—A Mechanistic Alternative for Radicals in Polar Media? (pages 1985–1988)

      Dr. Hendrik Zipse

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419851

      Thumbnail image of graphical abstract

      The calculated activation barrier is much lower for nucleophilic substitution reactions in radicals than for those with closed-shell systems. Monte Carlo simulations of the studied model system (a) predict that this is valid for aqueous solution too. These results should therefore also be relevant for radical chemistry under physiological conditions.

  4. Corrigenda

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Corrigenda
    6. Book Reviews
    7. New Books
    1. You have free access to this content
      Corrigendum (page 1988)

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419881

  5. Book Reviews

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Corrigenda
    6. Book Reviews
    7. New Books
    1. Book Review: Organic Phtochemistry, Principles and Applications. By J. Kagan (page 1990)

      Axel G. Griesbeck

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419901

    2. Book Review: Reactivity in Molecular Crystals. Edited by Y. Ohashi (pages 1991–1992)

      Gerd Kaupp

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419911

  6. New Books

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Corrigenda
    6. Book Reviews
    7. New Books
    1. New Books (Angew. Chem. Int. Ed. Engl. 19/1994) (page 1994)

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.199419941

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