Angewandte Chemie International Edition in English

Cover image for Vol. 18 Issue 8

August 1979

Volume 18, Issue 8

Pages 563–639

Currently known as: Angewandte Chemie International Edition

  1. Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    1. Stereochemistry of [2,3]Sigmatropic Rearrangements (pages 563–572)

      Prof. Dr. Reinhard W. Hoffmann

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197905633

      Thumbnail image of graphical abstract

      Exploitation of the interrelatoionship between prochirality and chirality in [2,3] sigmatriopic syntheses permits stereoselective syntheses. e.g of natural products.

    2. Adiabatic Photoreactions of Organic Molecules (pages 572–586)

      Prof. Dr. Nicholas J. Turro, Prof. Dr. Jeffrey McVey, Prof. Dr. V. Ramamurthy and Dr. Peter Lechtken

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197905721

      Thumbnail image of graphical abstract

      An insight into energetic aspects of photochemical reactions is provided by the study of adiabatic reactions; in such reactions a “representative point” traverses a single energy surface. The article surveys examples of more complicated transformation including fragmentations and geometrical isomerization.

    3. Compounds of Alkali Metal Anions (pages 587–598)

      Prof. Dr. James L. Dye

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197905871

      Thumbnail image of graphical abstract

      The key to solvent free salts of alkali metal anions (“alkalides”) and possibly solid “electrides” lies in the stablization of the cations by complexation with crown ethers or cryptands. The most throughly studied representative is the salt (1) which form relatively stable crystals with a golden luster.

      • equation image
    4. Spatial Structure Formation in Protein Gels (pages 599–610)

      Dr. M. G. Bezrukov

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197905991

      Thumbnail image of graphical abstract

      Research into protein gels is of both scientific and practical importance, e.g. in the food industry. In this sector, a knowledge of gel structure can be utilized to improve products and reduce manufacturing costs.

  2. Communications

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    1. endo-Hydroxytrioxatris-σ-homotropilidenes (pages 611–612)

      Prof. Dr. Horst Prinzbach, Dipl.-Chem. Christoph Rücker and Prof. Dr. Hans Fritz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906111

      Thumbnail image of graphical abstract

      Preperatively useful syntheses of the isomeric trioxatris-σ-homotropilidene derivatives(2) and (3), R[DOUBLE BOND]H, start from the readily accessible dibromodiacetate (1), R[DOUBLE BOND]Ac. (2) and (3) are of interest as reactants for pontentially “trishomobenzenoid” carbenium ions.

    2. Hexamethyldisilane/Iodine: Convenient In Situ Generation of Iodotrimethylsilane (pages 612–614)

      Prof. Dr. George A. Olah, Subhash C. Narang, B. G. Balaram Gupta and Ripudaman Malhotra

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906121

      Organic syntheses involving iodotrimethylsilane, e.g. cleavage of esters, ethers, snd carbamates under mild conditions, have advantages but Me3SiI is not readily obtainable and is also a sensitive compound. These difficulties are overcome by the Me3SiSiMe3/I2 reagent which can be used for convenient in-situ generation of Me3SiI.

      • equation image
    3. Formic Anhydride (page 614)

      Prof. Dr. George A. Olah, Dr. Yashwant D. Vankar, Massoud Arvanaghi and Prof. Jean Sommer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906141

      The parent compound of carboxylic anhydrides—formic anhydride—has now been synthesized in ethereal solution at −78° C by four different methods, and charactrized by 1H-NMR, 13C-NMR, and IR spectroscopy. The anhydride undergoes partial decomposition to formic acid on distillation of the solutions, even at low temperature.

      • equation image
    4. [2 + 2]-Cycloaddition of a Vinyl Cation (pages 614–615)

      Dipl.-Chem. Günter Hammen and Prof. Dr. Michael Hanack

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906142

      Thumbnail image of graphical abstract

      The first cycloaddition to a vinyl catoin has now been accomplished: (2), obtained from (1) by solvolysis in the presence of AgBF4, reacts with cyclohexene to give mainly the cation (3) and thence to (4). In contrast, reaction with F3CCOOAg gives only the ester [(1), F3CCOO in place of Br]; the pronounced nucleophilic character of the trifluoroacetate ion prevents cycloadditon (An = p-methoxyphenyl).

    5. Synthesis and Intramolecular 1,3 Cl,H Disproportionation of Ethyl 2,2-Dichloro-2-(dimethylamino)-acetate (pages 615–616)

      Lic. Chem. Fabienne Huys, Dipl.-Ing. Robert Merényi, Dr. Zdenek Janousek, Dr. Lucien Stella and Prof. Dr. Heinz Günter Viehe

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906151

      Thumbnail image of graphical abstract

      Compounds having geminal capto-dative substitutents contain a donor and an acceptor group bonded to the same C atom;such substitution stabilizes radicals. Compound (1) is an example; its remarkable Cl,H disproportionation to give the glyoxalic ester derivative (2) probably proceeds via a radical.

    6. Intramolecular Cl,H Disproportionation of an Oxamide Chloride. An Entry to Imidazole Derivatives (pages 616–617)

      Dr. Zdenek Janousek, Lic. Chem. Fabienne Huys, Dr. Loïc René, Lic. Chem. Michèle Masquelier, Dr. Lucien Stella, Dipl.-Ing. Robert Merényi and Prof. Dr. Heinz Günter Viehe

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906161

      Thumbnail image of graphical abstract

      The key step of exhaustive chlorination of tetramethyldithiooxamide(1), which surprisingly led to the new imidazolium salt (4), is Cl,H disproportionation of (2) (capto-dative substitution) to give (3). Compound (2), precipitates on chlorination of Me2NC[TRIPLE BOND]CNMe2, but cannot be isolated.

    7. Acidity of Acetophenone Enol in Aqueous Solution (pages 617–619)

      Dipl.-Chem. Pavel Haspra, Dipl.-Chem. Alfred Sutter and Priv.-Doz. Dr. Jakob Wirz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906171

      Thumbnail image of graphical abstract

      Thermodynamically unstable enols(1) are of interest as primary products of Norrish Type II cleavage of ketones—butyrophenone in this case—in alkaline solution. Since (1) quickly forms the enolate, which is only slowly protonated to the ketone (2), it is possible to measure the pK value directly by flash photolytic “titration” (pK = 10.34 ± 0.05)

    8. Redox Addition/Elimination Processes of Cluster-Bound Ligands: Oxidative Elimination of CO from Co3(CO)9C[DOUBLE BOND]OH and Reductive Addition of Acetylene to Co3(CO)9H (pages 619–620)

      Dr. Giuseppe Fachinetti, Dr. Sergio Pucci, Prof. Pier Francesco Zanazzi and Dr. Uncharee Methong

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906191

      Thumbnail image of graphical abstract

      Hydrogenation of acetylene with the hydrido cluster(1) in solution at room temperature leads immediately to the saturated compound (2). The cluster (1) was obtained from Co3(CO)9C[BOND]OH by oxidative elimination of CO and isolated at low temperature.

    9. Asymmetric Hydrogenation of (Z)-α-(Acetylamino)-cinnamic Acid by a Rh/norphos Catalyst (pages 620–621)

      Prof. Dr. Henri Brunner and Dr. Willigis Pieronczyk

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906201

      Thumbnail image of graphical abstract

      A generalizable procedure for production of pure enantiomeric chelating phosphanes is based on the surprisingly facile resolution of the corresponding phosphane oxides—(±)-norphosO in this case—with L-([BOND])-dibenzoyltartaric acid. (+)- and ([BOND])-norphosO (optically pure after two separation steps) can reduced by SiHCl3 to (+)- and ([BOND]) norphos, respectively, which from valuable catalysts for asymmetric hydrogenation with Rh compounds.

    10. Regioselective Alkylation of 1,4,5-Trihydroxy-9,10-anthraquinone with Formaldehyde and Glyoxylic Acid (pages 621–622)

      Dr. Karsten Krohn

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906211

      Thumbnail image of graphical abstract

      The ring system of the cytostatically active anthracycline antibiotics is being increasingly synthesized by intramolecular cylization. Reaction of (1) with glyoxylic acid, reduction and esterification of the primery product gave the monoester (2), R1 = R2 = H, R3 = CH2CO2CH3, which can converted in only two steps into 9-dexoy-ε-rhodomycinone (3).

    11. Competition in the Three-Component System Triphenylphosphane/Azo Ester/3-Hydroxy-Carboxylic Acid: OH[BOND] versus COOH-Activation (pages 622–623)

      Dr. Johann Mulzer, Gisela Brüntrup and Alexander Chucholowski

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906221

      Thumbnail image of graphical abstract

      The question whether hydroxy carboxylic acid are activated at the OH and/or the COOH group is of considerable importance, e.g. in syntheses of macrolides and peptides. IN the system (1) ([DOUBLE BOND]PPh3 + azo ester)/(2) the extent of reaction at OH and/or COOH depends upon R1 and R1; Q = ((3) + (4))/(5) can be correlated almost completely with Taft's steric parameter Es.

    12. Complexes of γ-Cyclodextrin with Crown Ethers, Cryptands, Coronates, and Cryptates (pages 623–624)

      Prof. Dr. Fritz Vögtle and Walter M. Müller

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906231

      Thumbnail image of graphical abstract

      Cascade complexes are comparable with a set of three interfitting dolls: γ-cyclodextrin (γ-CD)—a ring of eight glucose molecules—accommodates a small crown ether (see model) or cryptand, which in turm can take up a cation. The [12] crown-4-LiSCN complex and the [2.2.1] ⊂ Ca(SCN)2 cryptate from crystalline cascade complexes of stoichiometry 1:1 and 2:1, respectively, with γ-CD from aqueous solution.

    13. Colloidal Redox Catalysts for Evolution of Oxygen and for Light-Induced Evolution of Hydrogen from Water (pages 624–626)

      Dr. John Kiwi and Prof. Dr. Michael Grätzel

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906241

      Chemical utilization of the sun's radiation is very attractive aim. The evolution of oxygen and, on irradiation, hydrogen from water in the presence of redox catalysts are known, but rather slow processes. Colloidal ruthenium and other metals catalyze these reactions better than less finely divided materials.

    14. CS2- and CS3-Bridged Transition Metal Complexes—Directed Synthesis of Metallodithiocarboxylato-Metal Complexes (pages 626–627)

      Prof. Dr. Wolf Peter Fehlhammer, Dr. Andreas Mayr and Dipl.-Chem. Heribert Stolzenberg

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906261

      Thumbnail image of graphical abstract

      Di- and trinuclear transition metal complexes with the structural units(1) and (2) present in the same molecule have now been made accessible by studies on the basic metal/heteroallene/acid or Lewis acid metal system. An apt example of directed synthesis is the production of complex (3).

    15. (C5H5)3Co3(CS)(S); The First Complex to Have a μ3-Thiocarbonyl Bridge (pages 627–628)

      Prof. Dr. Helmut Werner and Dr. Konrad Leonhard

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906271

      Thumbnail image of graphical abstract

      The complex lignand CS follows in the footsteps the classical ligand CO. The complex (1), with a μ3-thiocarbonyl bridge, has now been synthesized as the missing member of the series LnM[BOND]CS, LnM22-CS), LnM33-CS), long known in the case of CO.

    16. [{Cu3WS3Cl}(PPh3)3O], Directed Synthesis of a Compound Containing Different Metal Atoms in a Cu-bane-like Skeleton (pages 628–629)

      Prof. Dr. Achim Müller, Dr. Theng Khing Hwang and Dipl.-Chem. Hartmut Bögge

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906281

      Thumbnail image of graphical abstract

      A “synthon” suitable for a copper- and sulfurcontaining compound with a cubane skeleton is the “ready-made corner” OWSmath image. Reaction of Cs2WOS3 with CuCL2 and PPh3 expectedly (preferred formation of Cu[BOND]S as aginst Cu[BOND]O bonds) gives comples (1). Cu-bane-type structure containing Cu and S were formerly unknown.

    17. Existence and Bond Energy of the Cesium Auride Molecule (pages 629–630)

      Dipl.-Ing. Bernd Busse and Prof. Dr. Konrad G. Weil

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906291

      Detection of cesium auride (CsAu) by mass spectrometry represents the first success in the study of systems of two metals with a large difference in electronegativity. The fragmentation energy yields a value of D (CsAu) ≈ 460 ± 30 kJ/mol for the bond energy. The stability of CsAu is determined mainly by an ionic bonding component.

    18. Complexes of Nitrogen-Containing Crown Ether Surfactants with Stable Silver Atoms (pages 630–631)

      Dr. Robin Humphry-Baker, Prof. Dr. Michael Grätzel, Prof. Dr. Pietro Tundo and Prof. Dr. Ezio Pelizzetti

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906301

      Thumbnail image of graphical abstract

      Photochemical reduction of complexed Ag+ ions to stable complexed Ag atoms can be accomplished with the aid of the heterocycle (1), which combines the properties of a crown ether and of a surfactant. (1) Ag+ is formed spontaneously from (1) and AgNO3; reduction with visible light requires a cyanine dye as sensitizer.

    19. η5-Cyclopentadienylchromium Complexes with Thiocarbonyl and Nitrosyl Ligands (pages 631–632)

      Prof. Dr. Max Herberhold and Dr. Paul D. Smith

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906311

      Thumbnail image of graphical abstract

      Three new chromium complexes containing the rare ligand combination CS/NO have been synthesized with the aim of comparing the acceptor strength of diatomic lignands CO, CS, and NO. It can be deduced from the spectra that CS in (1) is a more effective acceptor than CO in CpCr(CO)2(NO). In the cation (3), however, CS is a weaker acceptor than CO in [CpCr(CO)(NO)2]+. These observations are in accord with rules proposed by Andrews.

    20. Reaction of α-Lithioacetic Acid Esters with Succinic Anhydrides (pages 632–633)

      Dr. Franz-Peter Montforts and Dipl.-Chem. Silvio Ofner

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906321

      Thumbnail image of graphical abstract

      A considerably improved synthesis of β-ketoadipic esters(3) and (4)—important intermediates for the synthesis of natural products—has been accomplished as shown below. (1), R1[DOUBLE BOND]CH3, reacts preferentially at the substituted carbonyl function; this is the first example of regioselective addition of a nucleophile with CC linkage by the “Bürgi-Duntiz principle”.

    21. New Evidence for Zwitterionic Intermediates in the Wittig Reaction (pages 633–634)

      Prof. Dr. Manfred Schlosser and Dr. Huynh Ba Tuong

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906331

      Thumbnail image of graphical abstract

      The course of the Wittig reaction is still a topic of controversy; oxaphosphetanes (2) have been confirmed, betaines (1) not ruled out. Reaction of Ph3P C⊖(Me) CD2OLi with CH2O and that of the non-deuterated compound with CD2O lead to the same mixture of deuterated allyl alcohols. This result indicates an equilibrium between the different oxaphosphetans, i.e. the existence of a zwitterion.

    22. A Fragmentational Approach to Macrolides: (5-E, 8-Z)-6-methyl-5,8-undecadien-11-olide (pages 634–636)

      Dr. Daniel Sternbach, dipl. Ing.-Chem. Fritz Jaisli, dipl. sc. nat. Marco Bonetti, Prof. Dr. Albert Eschenmoser and Prof. Dr. Masayuki Shibuya

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906341

      Thumbnail image of graphical abstract

      Decarboxylative double fragmentation of type A is the key step in the synthesis of the unsaturated lactone (2) from the amidinium salt (1). The diastereomer of (1) also gives (2). The isomeric lactone (3) can be obtained analogously from diastereomeric amidinium salts.

    23. A Fragmentational Approach to Macrolides: (5-E,9-E)-6-methyl-5,9-undecadien-11-olide (pages 636–637)

      Dipl. Ing. -Chem. Fritz Jaisli, Prof. Dr. Albert Eschenmoser and Prof. Dr. Masayuki Shibuya

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906361

      Thumbnail image of graphical abstract

      Decarboxylative double fragmentation of type A is the key step in the synthesis of the unsaturated lactone (2) from the amidinium salt (1). The diastereomer of (1) also gives (2). The isomeric lactone (3) can be obtained analogously from diastereomeric amidinium salts.

    24. Steric Course of the Reduction of Ketoacetal Esters with Alkali Metals in Liquid Ammonia (pages 637–638)

      dipl. Ing.-Chem. Fritz Jaisli, Dr. Daniel Sternbach, Prof. Dr. Albert Eschenmoser and Prof. Dr. Masayuki Shibuya

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.197906371

      Thumbnail image of graphical abstract

      The stereochemistry of the reduction of keto groups such as in (1) by alkali metals is influenced by neighboring oxygen functions. Compounds (1). R1, R2[DOUBLE BOND]H, CO2Me, give (2) and (3) in th ratio 1:2.5–3. This unexpected finding is explained in terms of stabilization of the axial alkoxide corresponding to (3) by a Li bridge. Na+ and K + are too large for bridge formation; they give mainly (2).

  3. Book Reviews

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

SEARCH

SEARCH BY CITATION