Angewandte Chemie International Edition in English

Cover image for Vol. 20 Issue 10

October 1981

Volume 20, Issue 10

Pages 819–898

Currently known as: Angewandte Chemie International Edition

  1. Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    1. α,ω-Diisocyanatocarbodiimides, -Polycarbodiimides, and Their Derivatives (pages 819–830)

      Dr. Kuno Wagner, Dr. Kurt Findeisen, Dr. Walter Schäfer and Dr. Werner Dietrich

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108193

      The cumulative double bonds in the molecule predestine the title compounds (1) as attractive components for polyaddition reactions. Compounds (1) can be synthesized on an industrial scale by catalytic “carbodimerization”.

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    2. Analysis of Low Molecular Weight Homologues of Fiber-Forming Polycondensates (pages 831–840)

      Prof. Dr. V. Rossbach

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108311

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      Oligomers in and on polymer fibers—as illustrated on the right—are undesirable “natural impurities”; nevertheless, they serve as valuable model and calibration substances. A versatile analytical procedure is required in order to determine the purity and molecular homogeneity of oligomers.

    3. The Critical Screening and Assessment of Scientific Results without Loss of Information—Possible or Not? (pages 841–849)

      Prof. Dr. Reiner Luckenbach, Dr. Reinhard Ecker and Dr. Josef Sunkel

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108411

      The question posed in the title can, in the case of organic chemistry, be discussed on the basis of the criteria developed and tested by the Beilstein Institute from 100 years of experience for the critical screening of scientific results from the primary literature without loss of information. The extent of data reduction possible in this way is demonstrated for a few examples.

    4. Replication and Evolution in Inorganic Systems (pages 850–860)

      Prof. Dr. Armin Weiss

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108501

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      An “inorganic” intermediate in the creation of life certainly lies within the realm of possibility: Spontaneous self-multiplication (replication) has been demonstrated in layer silicates; errors in replication and their feedback, together with environmental influences, may lead to mutants with higher or lower replication rates, thus enabling evolution.

  2. Communications

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    1. Electro-Enzymatic and Electro-Microbial Stereospecific Reductions (pages 861–863)

      Prof. Dr. Helmut Simon, Dr. Helmut Günther, Dr. Johann Bader and Dr. Wilhelm Tischer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108611

      The hydrogenation of prochiral α,β-unsaturated carboxylates and aldehydes to chiral compounds can be accomplished electrochemically, both with isolated enoate reductase as well as with whole bacteria cells which contain this enzyme; methylviologen functions as electron-transfer agent. Since NAD+ can also be reduced to NADH, in principle all substrates of NAD-dependent enzymes can be stereospecifically hydrogenated with this method.

    2. Cyclopropanation with Dimethylcarbene (pages 863–864)

      Prof. Dr. Peter Fischer and Dipl.-Chem. Gerhard Schaefer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108631

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      The first preparatively useful entry to dimethylcarbene is the α-elimination from 2,2-di-bromopropane with n-butyllithium in diethyl ether at −70°C without auxiliary bases. For example, hexamethylcyclopropane (1) can be prepared in this way in 46% yield.

    3. 2-Acylbutadienes and Their Tricarbonyliron Complexes from Butatriene(hexacarbonyl)diiron Complexes via Friedel-Crafts Acylation (pages 864–865)

      Prof. Dr. Michel Franck-Neumann, Dr. Daniel Martina and Dr. Francis Brion

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108641

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      The extremely useful synthetic building blocks, 2-acylbutadienes, can be isolated in a novel way, either as the tricarbonyliron complexes (1), R [BOND] CH3, C6H5, or in a free form such as the tetramethyl derivative (2). (1), R [BOND] CH3, can be demetalated; the free acetylbutadiene immediately dimerizes or can be trapped with dienes.

    4. Investigation of Valence Isomerism Cyclobutadiene—Bismethylenecyclobutene—[4]Radialene (pages 865–867)

      Prof. Dr. Herbert Meier, Dipl.-Chem. Toni Echter and Dipl.-Chem. Oswald Zimmer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108651

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      1,5-Cyclooctadien-3-yne (1)already dimerizes at room temperature. The initial product (2), which has the cyclobutadiene structure, is converted by electro-cyclic reaction into (3) and (4). A 400-MHz 1H-NMR spectrum shows that the valence isomer (3) preponderates considerably in the equilibrium. The mixture of dimers reacts spontaneously with 4-phenyl-1,2,4-triazoline-3,5-dione.

    5. Reactions of a Heterocyclic System Having Ambidentate Reactivity (pages 867–868)

      Priv. Doz. Dr. Johann Gasteiger, Dr. Ulrich Strauß and Priv. Doz. Dr. Ulrich Schubert

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108671

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      The α-phenylhydrazono-2,5-dihydro-2-thiazole acetic acid esters (1), which can be attacked electrophilically and nucleophilically, are initially deprotonated in an alkaline medium. Intramolecular attack of the anion at the azomethine group affords the heterobicycle (2), which is in equilibrium with the dihydrotriazine (3) in solution; only (2) is present in the crystal.

    6. The 2-Chlorooxirane–α-Chloroketone Reactivity Spectrum (pages 868–869)

      Priv. Doz. Dr. Johann Gasteiger and Dr. Christian Herzig

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108681

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      2-Chlorooxiranes (3) are not only more reactive than 2-chloroketones (1), but also react with nucleophiles to give other products. Thus, (1) reacts with P(OMe)3 to give the phosphate (2), while (3) yields the phosphonate (4).

    7. Me3C[BOND]P(CI)[BOND]SiMe3, the First P-Halogenated Silylphosphane (pages 869–870)

      Prof. Dr. Rolf Appel and Dipl.-Chem. Wilfried Paulen

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108691

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      Almost quantitative yields of the reactive title compound (2) containing the partial structure Cl[BOND]P[BOND]Si can be prepared from stoichiometric amounts of (1) and hexachloroethane. Compound (2) loses Me3SiCl in toluene, even at room temperature, slowly forming the likewise novel, unsymmetrical diphosphane (3).

    8. A Boron-Boron One-Electron π-Bond (pages 870–871)

      Dipl.-Chem. Hartmut Klusik and Prof. Dr. Armin Berndt

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108701

      Thumbnail image of graphical abstract

      The simplest boron-boron π-bond is to be found in the radical anion (1); from the ESR spectrum of (1b) it follows that each of the two boron atoms and each of the four hydrogen atoms in the two sets are equivalent. (1) has a conformation in which each pair of tert-butyl groups of the trans-neopentyl groups shields both boron atoms from above and below.

    9. Novel Reactions of λ5-Phosphorins and Their Tricarbonylchromium Complexes (pages 871–872)

      Prof. Dr. Karl Dimroth and Hans Kaletsch

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108711

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      Cyclic phosphorus ylides such as (1) have been deprotonated for the first time; the “double” ylide (2) is formed which adds electrophiles E (D,CHmath image, PhCHmath image) with formation of (3). In principle, the same reactions are possible with the more strongly “ylidie” (CO)3Cr-complexes (4).

    10. Bis(thimethylgermyl)magnesium, the First Organogermylmagnesium Compound Isolated (pages 872–873)

      Priv.-Doz. Dr. Lutz Rösch

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108721

      The title compound (1) could be prepared for the first time by reaction of (Me3Ge)2Hg with Mg in dimethoxyethane, thus proving that compounds of this type are capable of existing. (1) forms colorless crystals which melt at 90 °C.

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    11. ENDOR Investigation of a Novel Organic Tetraradical in the Quintet State (pages 873–874)

      Dr. Burkhard Kirste, Prof. Dr. Wolfgang Harrer and Prof. Dr. Harry Kurreck

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108731

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      The first ENDOR-spectrum of an organic tetraradical, the almost tetrahedral galvinoxyl system (1), has been measured. The corresponding alcohol was prepared in a few steps from SiCl4 and 1,4-dibromobenzene. From it, the mono-, di-, tri-, and tetraradical could be generated selectively.

    12. Stereoisomerization of Aryl-Substituted Cyclopropanes via Trimethylene Radical Anions (pages 874–876)

      Prof. Dr. Gernot Boche and Dipl.-Chem. Helmut Wintermayr

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108741

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      The intermediary occurrence of trimethylene radical anions (2). during electron transfer to cyclopropancs (1) probably ensues via two consecutive reactions: the stereoisomerization of, e.g., trans,trans-(1) to cis,trans-(1) and cis,cis-(1) (44 :55 :1) and the dimerization of (2) after longer reaction time to a substituted hexane dianion.

    13. Nickel-Induced Coupling and Cleavage of CC-Bonds (pages 876–877)

      Prof. Dr. Heinz Hoberg and Dr. Antonio Herrera

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108761

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      The reversible formation of a CC bond in nickel complexes such as (1) has been studied, for example, in the reaction of (1), R = C6H5, with CO. At 80 °C (2) is formed, at 150 °C it decomposes again to (1). CO (> 10 bar) liberates the cyclobutendione derivative from (2).

    14. 1,2,3-Cycloheptatriene by Isomerization of Tricyclo[4.1.0.02,7]-hept-1(7)-ene (pages 877–878)

      Dipl.-Chem. Hans-Georg Zoch, Prof. Dr. Günter Szeimies, Dipl.-Chem. Roland Römer and cand. chem. Robert Schmitt

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108771

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      The bridged bicyclo[1.1.0]but-l(3)-ene derivative (1) rearranges thermally into the cumulene (2), which can be trapped with dienes or tert-butoxide. (1) was first generated by fluoride-induced trimethylsilyl bromide elimination.

    15. Aldehydes by Formylation of Grignard or Organolithium Reagents with N-Formylpiperidine (pages 878–879)

      Prof. Dr. George A. Olah and Mr. Massoud Arvanaghi

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108781

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      The standard repertoire of the preparative organic chemist may soon include the reaction of organolithium and Grignard compounds with N-formylpiper-idine, for it conveniently affords aldehydes in very good yields under mild conditions.

    16. Cyclobutanone and Cyclobutenone Derivatives by Reaction of Tertiary Amides with Alkenes or Alkynes (pages 879–880)

      Lic. Jean-Bernard Falmagne, Lic. José Escudero, Lic. Sofia Taleb-Sahraoui and Prof. Dr. Léon Ghosez

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108791

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      Cyclobutanones (1) and cyclobutenones (2), R1 and/or R2 = alkyl, aryl, H, often used as synthetic building blocks, could be prepared from N,N-dialkylamides, trifluorome-thanesulfonic acid anhydride and alkenes or alkynes in the presence of collidine. N,N-Dialkyl-N-alkylideneammonium(keteniminium) salts occur as intermediates.

    17. Anionic Cycloaddition on Electron-Deficient Alkynes–Synthesis and Stereochemistry of 3-Pyrroline-3-carboxylic Acid N,N-Dimethylamides (pages 880–881)

      Dr. Liliane Vo Quang, Dipl.-Ing. Henri Gaessler and Dr. Yen Vo Quang

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108801

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      An entry to 3-pyrroline derivatives such as (2), with defined spatial arrangement of the substituents on C-2 and C-5, is opened up by the reaction of (1) with electron-deficient alkynes. Compounds of type (2) are of interest because of their biological activity.

    18. (E,E)-5-Amino-2,4-pentadienal: The First Preparative Synthesis of Hydrolyzed Pyridine (pages 881–882)

      Dr. Dieter Reinehr and Dr. Tammo Winkler

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108811

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      The main product of the photohydrolysis of pyridine, the title compound (1a), had previously only been characterized spectroscopically. Its synthesis on the preparative scale [by-product: (1b)] was accomplished by reaction of (2) with isopropylamine.

    19. Oxidation of Isatins to Anthranilic Acid Esters (pages 882–883)

      Dr. Gernot Reissenweber and Dr. Dietrich Mangold

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108821

      Thumbnail image of graphical abstract

      A direct route to multi-substituted anthranilic acid methyl esters (2) is outlined below. The educts (1) are conveniently obtained from aniline derivatives.

    20. Vinyl Isocyanate by Thermal Dehydrohalogenation of 1-Haloethylcarbamoyl Halides with α-Pinene (page 883)

      Dr. Karl-Heinz König, Dr. Karl-Heinz Feuerherd, Dr. Volker M. Schwendemann and Dr. Heinz-Günter Oeser

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108831

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      Vinyl isocyanate (3) and the novel 1-chloroethyl isocyanate (2) are formed on heating the acid chloride (1) in the presence of α-pinene. The increase in proportion of (3) in the product mixture as a function of the residence time could be explained in terms of an equilibrium between (2) and CH3[BOND]CH[DOUBLE BOND]N[BOND]COCl (X = Cl).

    21. Thiatriazinones via a Novel 1,5-Carboxylic Ester Shift (pages 884–885)

      Dr. Rolf-Dieter Acker, Dr. Gerhard Hamprecht and Dr. Erich Hädicke

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108841

      Thumbnail image of graphical abstract

      Novel key thiatriazinone structures (1)–regarded as a combination of uracil and sulfonamide–are of interest because of their potential biological activity. A novel 1,5-carb-oxylate-shift opens up a convenient route.

    22. 4,5-Dihydroisoxazoles from Cyclopropyl Ketone Oximes (page 885)

      Dr. Costin N. Rentzea

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108851

      Thumbnail image of graphical abstract

      A change in the course of reaction of cyclopropyl styryl ketones (1) is possible by addition of 1,2,4-triazole. Reaction of NH2OH·HCl with adduct (2) furnishes an oxime, which unlike the (1)-oxime, however, does not now form the six-membered ring compound (4), but the five-membered ring compound (3) (R = p-X[BOND]C6H4).

    23. Base Catalyzed Asymmetric Induction of the Reaction of Methyl(phenyl)ketene with 1-Phenylethanol: Method of Obtaining Hydratropic Acid in High Enantiomeric Purity (pages 885–887)

      Dipl.-Chem. Joachim Jähme and Prof. Dr. Christoph Rüchardt

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108852

      Thumbnail image of graphical abstract

      The conversion of (±)-hydratropaoyl chloride into (S)-(+)-hydratropic acid (4) can be achieved with (S)-(−)-1-phenylethanol (2) as chiral auxiliary agent in the following way: Generation of the ketene (1) from the acid chloride in situ, reaction with (S)-(−)-(2) in the presence of a base to give a mixture of the diastereomers (3) [with pyridine, e.g., (S,S) :(R,S) = 88 :12], hydrolysis of (S)-(+)-(4) with recovery of (S)-(−)-(2).

    24. Experimental Electron Density Determination of a Dimetallacyclopropane-Type μ-Methylene Complex (pages 887–888)

      Dr. Dore Augusto Clemente, Dr. Bernard Rees, Dr. Giuliano Bandoli, Prof. Dr. Marina Cingi Biagini, Barbara Reiter and Prof. Dr. Wolfgang A. Herrmann

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108871

      A considerable negative charge on the bridge carbon atom in the dimanganacyclopropane complex (1) has been demonstrated by determination of the electron density. This finding is in agreement with the result of detailed MO calculations. No accumulation of charge density was found between the two Mn atoms, although according to MO calculations direct metal-metal bonding is present. It must be assumed that there is inadequate overlap of the corresponding metal orbitals.

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    25. Stereochemistry of the Ozonolysis of Alkenes: Ozonide- versus Carbonyl Oxide-Control (pages 888–889)

      Priv.-Doz. Dr. Dieter Cremer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108881

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      In the three-step mechanism of the ozonolysis of alkenes suggested by Criegee, ab initio calculations enable statements to be made about the energetics and stereochemistry of step (b). In lower alkenes the carbonyl oxide, in higher alkenes the primary ozonide determines the stereochemistry. According to quantum-chemical calculations the syn-isomers of alkylcarbonyl oxides are about 3–4 kcal/mol more stable than the anti-isomers.

    26. On the Structure of the Helical N-Terminus in Alamethicin—α-Helix or 310-Helix? (pages 889–890)

      Dipl.-Chem. Thomas Butters, Dipl.-Chem. Peter Hütter, Prof. Dr. Günther Jung, Dipl.-Chem. Norbert Pauls, Dipl.-Chem. Heribert Schmitt, Prof. Dr. George M. Sheldrick and Doz. Dr. Werner Winter

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108891

      The crystal structure of the helical undecapeptide (1), a model of the N-terminal alamethicin helix, suggests that no 310- but an α-helix conformation is most probably present in the antibiotics alamethicin, trichotoxin, and suzukacillin. The nine N-terminal amino acids of (1) are part of an α-helix.

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    27. Selective Micellar Catalysis with Histidinyl Surfactants of Defined Absolute Configuration (pages 890–892)

      Dr. John M. Brown, Dr. Richard L. Elliott, Dr. Colin G. Griggs, Prof. Dr. Günter Helmchen and Dr. Günter Nill

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108901

      Thumbnail image of graphical abstract

      The stereoselectivity of the micellar-catalyzed hydrolysis of amino acid esters (2) by the histidinyl surfactants (1) strongly depends on their absolute configuration: In presence of the R,S-configurated surfactant (1), which like the S,S-diastereomer was also prepared in a few steps from γ-butyrolactone, S-(2) hydrolyzes 2.5 times as fast as R-(2).

    28. A Mild and Effective Method for the Reactivation or Maintenance of the Activity of Heterogeneous Catalysts (pages 892–894)

      Dr. Helmut Tiltscher, Dipl.-Chem. Helmut Wolf and Dipl.-Ing. Joachim Schelchshorn

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108921

      The influence of increasing the pressure into the supercritical region on heterogeneous catalysts has been investigated, for example, on the isomerization of 1-hexene in the presence of 2-chlorohexane (500:1) on γ-Al2O3. On increasing the pressure the catalyst could even be reactivated when covered with volatile substances or when specific catalyst poisons had been added.

    29. Synthesis of Glycopeptides: Selective Carboxy-Deblocking of Completely Protected Glucosylserine Derivatives (pages 894–895)

      Prof. Dr. Horst Kunz and Dipl.-Chem. Michael Buchholz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108941

      Thumbnail image of graphical abstract

      Models for acid- and base-sensitive glycopeptides such as (1), with O-glycosidically linked serine moieties, have been synthesized by HBr-elimination from protected glucosyl bromide and protected serine esters with CF3SO3Ag. Selective cleavage of the ester protecting group in (1) with NaI/Zn enables chain lengthening with further amino acid 2-bromoethyl esters.

    30. Synthesis of Glycopeptides: Selective Amino-Deblocking of 2-Phosphonioethoxycarbonyl-Protected Asparagine N-Acetylglucosamine Moieties (pages 895–896)

      Prof. Dr. Horst Kunz and Dipl.-Chem. Hermann Kauth

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198108951

      Thumbnail image of graphical abstract

      Models for acid- and base-sensitive glycopeptides of type (1), with N-glycosidically linked asparagine moieties, can be synthesized by employing the Peoc-protecting group (Ph3P[BOND](CH2)2[BOND]O[BOND]CO), which can be selectively removed, e.g., with 5% HNEt2 in tBuOH. In this way, it is possible to increase the chain length with further N-Peoc amino acids.

  3. Book Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews

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