Angewandte Chemie International Edition in English

Cover image for Vol. 17 Issue 12

December 1978

Volume 17, Issue 12

Pages 875–979

Currently known as: Angewandte Chemie International Edition

  1. Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Author Index
    5. Subject Index
    1. Multistage Organic Redox Systems—A General Structural Principle (pages 875–886)

      Dr. Klaus Deuchert and Prof. Dr. Siegfried Hünig

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197808753

      Reversible two-stage electron transfer is possible with organic compounds of the type X–(CH[DOUBLE BOND]CH)n–X; one or both of the end groups X can be replaced by Y. This general structural principle permits categorization of numerous known compounds and the design of new redox systems.

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    2. Physical and Chemical Properties of Dissolved Electrons (Excess Electrons) (pages 887–901)

      Prof. Dr. Ulrich Schindewolf

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197808871

      Of great importance in all radiolytic and photochemical processes are “dissolved electrons” generated by ionization in a gaseous, liquid, or solid solvent.

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    3. Pore Sizes of Solids (pages 901–908)

      Prof. Dr. István Halász and Dr. Kornél Martin

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809011

      Size exclusion chromatography (SEC) on solids provides a means of separating polymers according to their molecular weight. Conversely, the porous nature (pore volume, specific surface, volume of closed pores, pore size distribution) of solids such as silica gel can be determined if a set of polymers of known molecular weight is available.

    4. Superacid-Catalyzed Oxygenation of Alkanes. [New synthetic methods (26)] (pages 909–931)

      Prof. Dr. Georg A. Olah, Dr. David G. Parker and Dr. Norihiko Yoneda

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809091

      “Paraffins” can be oxyfunctionalized by reaction with ozone or hydrogen peroxide in highly acidic, weakly nucleophilic solvent systems, e.g. in FSO3H/SbF5/SO2. The reactions proceed via pentacoordinated carbonium ions.

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  2. Communications

    1. Top of page
    2. Reviews
    3. Communications
    4. Author Index
    5. Subject Index
    1. Use of a Photoelectron Spectrometer in Gas Phase Analysis: Cyanogen and Hydrogen Cyanide (pages 932–933)

      Prof. Dr. Hans Bock, Dr. Bahman Solouki and Dipl.-Chem. Jörg Wittmann

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809321

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      New applications of photoelectron spectroscopy have been found in the elucidation of the course of gas phase reactions and the optimization of such reactions. For example, a PES analytical technique has been developed for acetonitrile (1), cyanogen (2), malononitrile, and hydrogen cyanide; the reaction of (1) with (2) was subsequently monitored by PE spectroscopy. The copper-catalyzed formation of benzonitrile (3) in the gas phase could be optimized: about 40 wt% of (3) were formed in a single passage over Cu/AI2O3 at 850 K/10 torr.

    2. Copper-Catalyzed Cyanation of Benzene in the Gas Phase (pages 933–934)

      Prof. Dr. Hans Bock, Dr. Bahman Solouki, Dipl.-Chem. Jörg Wittmann and Dr. Hans-Jürgen Arpe

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809331

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      New applications of photoelectron spectroscopy have been found in the elucidation of the course of gas phase reactions and the optimization of such reactions. For example, a PES analytical technique has been developed for acetonitrile (1), cyanogen (2), malononitrile, and hydrogen cyanide; the reaction of (1) with (2) was subsequently monitored by PE spectroscopy. The copper-catalyzed formation of benzonitrile (3) in the gas phase could be optimized: about 40 wt% of (3) were formed in a single passage over Cu/AI2O3 at 850 K/10 torr.

    3. Diastereoselective Radical Recombination and Variation in Thermal Stability of Diastereomeric Hydrocarbons (pages 934–935)

      Dipl.-Chem. Karl-Heinz Eichin, Kevin J. McCullough, Dr. Hans-Dieter Beckhaus and Prof. Dr. Christoph Rüchardt

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809341

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      An activation barrier to the dimerization of radicals has been detected for the first time by observations on diastereoselectivity. The radical (1) forms DL and meso dimers in the ratio of 1.66:1. Hence ΔΔG (135.2°C) is calculated as 0.4 kcal/mol.

    4. Synthesis and Characterization of Liquid-Crystalline Polymers with Cholesteric Phase (pages 935–936)

      Dr. Heino Finkelmann, Johanna Koldehoff and Prof. Dr. Helmut Ringsdorf

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809351

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      The first series of polymeric liquid crystals with a cholesteric phase has been prepared by copolymerization of the methacrylic esters (1) and (2). Pure poly-(1) forms a nematic phase; the cholesteric structure is induced by the chiral species (2).—Pure poly-(2) is not liquid crystalline.

    5. trans-3,6-Dioxa-9-azatris-σ-homobenzene and cis-Epoxyepimino-1,3-cyclohexadiene (pages 936–937)

      Dr. Eric Francotte, Dipl.-Ing. Robert Merényi and Prof. Dr. Heinz Günter Viehe

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809361

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      A facile entry to oxaazahomobenzene derivatives such as (2) is provided by the reaction of (1) with 1,3-dienes. Stereospecific addition is followed by rearrangement of the primary adduct.

    6. Correlation of the Absolute Configuration of Chiral Epoxides by Complexation Chromatography; Synthesis and Enantiomeric Purity of (+)- and (−)-1,2-Epoxypropane (pages 937–939)

      Univ.-Doz. Dr. Volker Schurig, Bernhard Koppenhöfer and Waldemar Bürkle

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809371

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      Chiroptical properties of chiral substrates can be determined by complexation chromatography. 10-9 g of crude, non-derivatized substance suffice for determination of optical purity; the rotation of the pure enantiomer need not be known. Moreover, the absolute configuration of three-membered ring heterocycles can be deduced from their retention behavior on a special nickel complex with the aid of a quadrant rule for (1), X[DOUBLE BOND]NH, O, S.

    7. Structure of the First Open-Chain Diorganotin Chalcogenide (page 939)

      Prof. Dr. Heinrich Puff, Anne Bongartz, Dr. Rolf Sievers and Dr. René Zimmer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809391

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      Polymeric diisopropyltin sulfide(1), a new stable modification of such compounds made up of long planar chains (X-ray structure analysis), is formed from iPr2SnCl2 and Na2S in DMF. Hitherto only puckered six- and planar four-membered rings were known in this class of compounds.

    8. Ozone Cleavage of Olefins with Formation of Ester Fragments (pages 939–940)

      Dipl.-Chem. Joachim Neumeister, Dr. Helmut Keul, Dr. Mahendra Pratap Saxena and Prof. Dr. Karl Griesbaum

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809392

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      High yields of esters, including dicarboxylic esters, are now directly accessible by ozonolysis of olefins and cyclic olefins in the anhydrous, HCl-containing solution of an alcohol.

    9. Demonstration of Diastereomeric Electron-Donor-Acceptor Complexes by 1H-NMR Spectroscopy (pages 940–942)

      Prof. Dr. Albrecht Mannschreck, Dipl.-Ing. Peter Roza, Prof. Dr. Hans Brockmann jr. and Dr. Thorsten Kemmer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809401

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      Intermolecular interactions in solution, such as the formation of donor-acceptor complexes, can be readily studied by 1H-NMR spectroscopy by means of a trick in the case of chiral compounds. Reaction of the donor, e.g. (RS)-(1), with an optically active acceptor, e.g. (R)-(2), gives the two diastereomeric complexes [(R)-(1) + (R)-(2)] and [(S)-(1) + (R)-(2)], whose NMR spectra differ: a signal splitting is observed.

    10. 1,5-Cyclooctadien-3-yne—A Novel, Highly Reactive C8H8 Hydrocarbon (pages 942–943)

      Prof. Dr. Herbert Meier, Toni Echter and Dipl.-Chem. Hermann Petersen

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809421

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      The new highly strained C8H8 isomer(1) is one of the relatively uncommon chiral hydrocarbons without an asymmetric C atom and is exceptionally reactive. Intramolecular transformation into cyclooctatetraene can be explained in terms of two thermally allowed, suprafacial 1,5 H shifts.

    11. 1,6-Dimethylbicyclo[4.4.1]undeca-2,4,7,9-tetraene—A Higher Vinylog of Norbornadiene (pages 943–944)

      Dipl.-Chem. Jürgen Frank, Dr. Wolfram Grimme and Dr. Johann Lex

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809431

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      Dimethylated “dihydromethano [10] annulene”, the title compound (1), has been synthesized in several steps. (1) is transformed into (2) at room temperature. This rearrangement could take place from a twist conformation having C2 symmetry.

    12. 1-(1-Adamantyl)-1-methylethoxycarbonyl: A New Protecting Group for Peptide Syntheses (pages 944–945)

      Dipl.-Chem. Hubert Kalbacher and Prof. Dr. Wolfgang Voelter

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809441

      Thumbnail image of graphical abstract

      Although many amino protecting groups are already available, not all wishes are satisfied. The new Adpoc group has the advantage that it resists hydrogenolysis and treatment with alkali, but is removed some 1000 times faster than the Boc group by CF3COOH in CH2Cl2.

    13. Regioselective Synthesis of the Anthraquinones Digito-purpone and Islandicin (pages 945–947)

      Dr. Manfred Braun

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809451

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      The synthesis of anthraquinone derivatives is of topical interest in view of the cytostatic action of daunomycin and adriamycin. The regioselective synthesis of the anthraquinones (1), R[DOUBLE BOND]H, and (2), R[DOUBLE BOND]H, has now been accomplished in 51 and 29% yield, respectively.

    14. The Synthesis of Unsymmetrical Tetraarylporphyrins on Solid Phases (page 947)

      Dr. Clifford C. Leznoff and Dr. Polina I. Svirskaya

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809471

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      Conventional syntheses of unsymmetrical tetraarylporphyrins do give the desired products in low yield, but only after extensive purification. A simple extraction step suffices in the solid phase synthesis of (1), R = p-tolyl, R′ = p- or m-hydroxyphenyl.

    15. Addition of Water to o-Phenylethynyl-Substituted Triphenylphosphanes (pages 947–948)

      Dr. Werner Winter

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809472

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      The stereospecific hydrogenation of a C[TRIPLE BOND]C bond and addition of oxygen to phosphorus are effected by straightforward recrystallization of (1), R, R′ = H and/or C[TRIPLE BOND]CPh, from commercial grade ethanol. A side product of unusual structure affords further information about the reaction mechanism.

    16. Enantiomerism and Diastereoisomerism of Bishelical Bilatriene Dimers in the Crystal Lattice (pages 948–949)

      Dr. Harald Lehner, Prof. Dr. Silvia E. Braslavsky and Prof. Dr. Kurt Schaffner

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809481

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      The formation of stereoisomeric bishelices in the crystal lattice of unsymmetrically substituted compounds such as (1) is the reason for the X-ray analytical disorder of the substituents. This effect could not previously be explained.

    17. Dipotassium Hexaisobutyldialuminate, a Complex Containing an Al[BOND]Al Bond (pages 949–950)

      Priv.-Doz. Dr. Heinz Hoberg and Dr. Siegfried Krause

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809491

      The new dialuminum complex(1) is formed by the route shown below (hexane, 20°C, 63% yield, brown crystals). A σ-interaction of the A1 atoms is deduced from the spectra and properties of (1).

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    18. 2,2′-Bipyridine(tetramethylcyclobutadiene)nickel(0) (pages 950–951)

      Dr. Udo Griebsch and Priv.-Doz. Dr. Heinz Hoberg

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809501

      The first monocyclobutadiene-nickel(0) complex, the bipyridine-stablized tetramethyl derivative (2), has been prepared from the nickel(II) complex (1). Compound (2) is diamagnetic, of remarkable thermal stability, sublimable in a vacuum, and hydrogenated only with difficulty.

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    19. Redox Properties of Zinc Tetrabenzporphyrin (pages 951–952)

      Prof. Dr. Arnd Vogler, Birgit Rethwisch, Dr. Horst Kunkely, Prof. Dr. Jürgen Hüttermann and Dr. Jürgen Otto Besenhard

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809511

      The redox potential of porphyrins could previously only be modified by variation of the central metal and additional axial ligands. However, it can also be considerably reduced by extension of the π-electron system of the porphyrins: in zinc tetrabenzporphyrin (containing a redox-inert metal) the potential difference between the first oxidation and the first reduction of the ring is only 1.84 V, as against ca. 2.25V in other porphyrins.

    20. Carbonyl(pyridine)iron(II) Tetrabenzporphyrin π-Radical Cation (pages 952–953)

      Prof. Dr. Arnd Vogler, Birgit Rethwisch, Dr. Horst Kunkely and Prof. Dr. Jürgen Hüttermann

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809521

      “Oxidation state isomerism” exists between porphyrins which differ only in the localization of their electrons. Such a system is that of the title compound [FeII(TBP+)(CO)(py)]⊕, in which one electron is removed from the porphyrin ring, and the corresponding (unknown) FeIII porphyrin.

    21. A New Example of a Dichromium Compound with a Supershort CrCr Quadruple Bond (page 953)

      Professor Dr. F. Albert Cotton, Dr. Brian E. Hanson and Dr. Gary W. Rice

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809531

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      The influence of the ligands on the length of the CrCr quadruple bond is not so well known as was previously thought. Thus the compound (1) contains a “supershort” CrCr bond but no benzene ring—hence these structural features are not coupled with each other.

    22. Thiooxalates as Dithiabutadienes (pages 953–954)

      Prof. Dr. Klaus Hartke, Dr. Thomas Kissel, Dipl.-Chem. Josef Quante and Dipl.-Chem. Günter Henssen

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809532

      Thumbnail image of graphical abstract

      1,2-Dithiocarbonyl compounds are heterodienes—or more precisely 1,4-dithiabutadienes—and should therefore undergo Diels-Alder reactions. It has now been found that the stable di- and tetrathiooxalic esters MeX—CS—CS—XMe (X[DOUBLE BOND]O or S) do indeed form cycloadducts, acting as 2π- or 4π-components.

    23. Norcaradiene and Cycloheptatriene Endoperoxides (pages 954–955)

      Prof. Dr. Waldemar Adam and Dr. Metin Balci

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809541

      Thumbnail image of graphical abstract

      Three types of Diels-Alder adducts can formally occur in the cycloheptatriene ⇌ norcaradiene system. All three expected products have now been isolated for the first time on reaction with singlet oxygen.

    24. syn,syn-1,6:8,17:10,15-Trismethano[18]annulene (pages 956–957)

      Dr. Wolfgang Wagemann, Dr. Masahiko Iyoda, Dr. Hans M. Deger, Dr. Johannes Sombroek and Prof. Dr. Emanuel Vogel

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809561

      Thumbnail image of graphical abstract

      The series of syn-methano-bridged [4n+2]annulene has been extended to include the title compound (3). Like (1) and (2), compound (3) possesses aromatic character but is air-sensitive.—The closely similar electronic spectra of the three homologs decorate the front cover of this issue.

    25. syn,syn-1,6:8,17:10,15-Trismethano[18]annulene Dication—Dication of a [4n+2]Annulene (pages 957–958)

      Dr. Hans M. Deger, Priv.-Doz. Dr. Klaus Müllen and Prof. Dr. Emanuel Vogel

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809571

      Thumbnail image of graphical abstract

      syn,syn-Trismethano[18]annulene gives the 4nπ dication(1) in superacid solution: this species was detected by its spectra and trapped with methanol. Charge accumulates at the four perimeter atoms of the central rings.

  3. Author Index

    1. Top of page
    2. Reviews
    3. Communications
    4. Author Index
    5. Subject Index
    1. Author Index (pages 965–968)

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809651

  4. Subject Index

    1. Top of page
    2. Reviews
    3. Communications
    4. Author Index
    5. Subject Index
    1. Subject Index (pages 969–979)

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197809691

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