Angewandte Chemie International Edition in English

Cover image for Vol. 24 Issue 4

April 1985

Volume 24, Issue 4

Pages 237–356

Currently known as: Angewandte Chemie International Edition

    1. Cover Picture (Angew. Chem. Int. Ed. Engl. 4/1985)

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198502371

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      The cover page shows schematically the main area of research of the Max-Planck-Institut für Kohlenforschung in Mülheim: the synthesis and structure elucidation of organometallic compounds and the study of their catalytic activity. The activity and selectivity of (η5-RC5H4)Co(cod) catalysts in the synthesis of pyridine is controlled by the R residue. If R is a donor, the 59Co-NMR signals are shifted upfield and the catalytic activity decreases; the R[BOND]C bond is orthogonal to the schematically drawn double bonds of the COD ligand (structure and measured points on right side). If R is an acceptor, Co is deshielded and the catalytic activity increases; the R[BOND]C bond is parallel to the COD double bonds (structure and measured points on left side). Further details on the structure-activity relationships for cobalt complexes in homogeneous catalysis are reported by H. Bönnemann in a review on p. 248.

    2. Graphical Abstract (Angew. Chem. Int. Ed. Engl. 4/1985)

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198502372

  1. Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    1. High-Resolution X-ray Crystallography—An Experimental Method for the Description of Chemical Bonds (pages 237–247)

      Dipl.-Chem. Klaus Angermund, Karl Heinz Claus, Dr. Richard Goddard and Prof. Dr. Carl Krüger

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198502373

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      The determination of the electron distribution in molecules is now made possible by the high accuracy of X-ray analysis. In this way, the electron density that results from the detormation of the spherical charge distribution as a consequence of chemical bond formation can be represented (example, 1,2,3-triazine, right).

    2. Organocobalt Compounds in the Synthesis of Pyridines–An Example of Structure-Effectivity Relationships in Homogeneous Catalýsis (pages 248–262)

      Prof. Dr. Helmut Bönnemann

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198502481

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      The successful optimization of the properties of a catalyst of the type [YCoL] for the synthesis of pyridine from alkynes and nitriles is achieved by variation of the ligands Y and L. As in 1, Y and L can be pentamethyl-cyclopentadienyl and cycloocatadiene.

    3. Catalytic Synthesis of Organolithium and Organomagnesium Compounds and of Lithium and Magnesium Hydrides—Applications in Organic Synthesis and Hydrogen Storage (pages 262–273)

      Prof. Dr. Borislav Bogdanović

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198502621

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      Catalytically prepared magnesium hydride is suitable as a high-temperature hydrogen storage material. “Magnesium-anthracene” 1 and a transition-metal halide serve as a homogeneous catalyst.

    4. Oxidation of Organometallic Compounds (pages 274–282)

      Prof. Dr. Jack Halpern

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198502741

      An essential step in syntheses involving transition metals, such as reaction (1), is the oxidation of the complex in order to liberate the product. Of interest is also the characterization of the usually short-lived primary products and the elucidation of the role played by the oxidation of organometallic compounds in catalytic oxidations–both biological and industrial.

      • equation image
    5. η3-Allylpalladium Compounds (pages 283–295)

      Dr. Peter W. Jolly

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198502831

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      The optimal use of palladium in homogeneous catalysts demands a thorough study of the chemistry of the Pd[BOND]C bond. Investigations of η3-allylpalladium compounds such as 1 afford deep insight into the course of Pd-catalyzed transformations of dienes.

    6. Reactive Organometallic Compounds Obtained from Metallocenes and Related Compounds and Their Synthetic Applications (pages 295–311)

      Priv.-Doz. Dr. Klaus Jonas

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198502951

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      The partial or total degradation of metallocenes, such as 1, and similar compounds opens up an efficient route to organotransition-metal complexes such as 2. These can in turn be used in a variety of ways for syntheses.

  2. Communications

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    1. Formation of Organoaluminium Compounds in the Mixture AlCl3[BOND]TiCl4[BOND]Al[BOND]C2H4 (pages 311–313)

      Dr. Heinz Martin, Helmut Bretinger and Fritz Fürbach

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503111

      In legal controversies concerning the patent rights for the Ziegler catalysts, publications of Max Fischer and of Hall and Nash have played an important role. It was claimed that the polymerization of ethylene under the given conditions was effected by a Ziegler catalyst. This claim has now been successfully disproved: no Et2AlCl is formed in the studies carried out by Fischer; the catalyst involved is therefore different from that described by Ziegler. As intermediates, the new compounds Cl2Al[BOND]CH2CH2[BOND]AlCl2 and (Cl2Al)2CH[BOND]CH3 could be identified and synthesized.

    2. Nickel-Catalyzed Cyclodimerization of 2-tert-Butyl- and 2-Trimethylsilyl-1,3-butadiene (pages 313–314)

      Dr. Tamas Bartik, Prof. Paul Heimbach, Dipl.-Chem. Thomas Himmler and Dr. Richard Mynott

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503131

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      An unexpectedly rapid cyclodimerization was observed for the title compounds 1 and 2. They react with Ni0 catalysts exclusively to give substituted 4-vinylcyclohexenes. The structure of the products could be elucidated by the 2D-INADEQUATE technique.—Surprisingly, PPh3 inhibits the reaction.

    3. Novel Trimerization of Cyclopentadiene with a Homogeneous, Bifunctional Palladium-Acid Catalyst System (pages 314–315)

      Dr. Arno Behr and Prof. Dr. Wilhelm Keim

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503141

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      Nearly total suppression of the dimerization and selective trimerization of cyclopentadiene is effected by a novel mixed catalyst formed from a palladium complex, a phosphane, and a carboxylic acid. The cyclopentene ring attached to the norbornane system of the trimers 1a, b is in the endo arrangement.

    4. A New Method for Determining Enantiomeric Excess, where the Sample Serves as its Own Reference (pages 315–316)

      Dr. Maurice L. Pasquier and Prof. Dr. Werner Marty

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503151

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      Measurable “diastereomeric interactions” between enantiomers in a sample can be used for the determination of the enantiomeric excess ee. The ee of 1 can be calculated from the ratio of the diastereomers m and e, which are formed from the bidentate ligand 1 and a nickel salt and which can be distinguished by NMR spectroscopy.

    5. 4-Methylene-1-cyclopentenes from Methylenecyclopropanes and Alkynyltrimethylsilanes (pages 316–317)

      Priv.-Doz. Dr. Paul Binger, Qui-Hao Lü and Petra Wedemann

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503161

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      [3 + 2]Cycloadditions between methylenecyclopropanes 1 and substituted alkynes 2 are achieved on a triarylphosphite(“TOPP”)-containing nickel(0) catalyst. The three 4-methylene-1-cyclopentenes 35, R and/or R′ ≠ H, are formed in the reaction with 1.

    6. cis-Triaza-tris-σ-homobenzene as Tridentate Ligand [La(C6H9N3)4·CH3CN·(ClO4)3]: LaN12 Complex with Icosahedral Coordination (pages 318–319)

      Dr. Reinhard Schwesinger, Dr. Klaus Piontek, Dr. Walter Littke and Prof. Dr. Horst Prinzbach

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503181

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      The title compound contains a LaN12 coordination polyhedron in which the “cis-benzenetriimine” functions as a tridentate ligand. The imino hydrogen atoms are oriented outwards. MN12 complexes, even those with small inorganic ligands, are very rare.

    7. I(py)2BF4, a New Reagent in Organic Synthesis: General Method for the 1,2-Iodofunctionalization of Olefins (pages 319–320)

      Prof. Dr. José Barluenga, José M. González, Dr. Pedro J. Campos and Prof. Dr. Gregorio Asensio

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503191

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      A variety of charged and uncharged nucleophiles (Nu) can be added to olefins using the title compound 1. The 1,2-functionalized compounds 2 are formed, which can be used as synthetic building blocks.

    8. Catalytic Transformations of Sesquiterpene Hydrocarbons on Alkali Metal/Aluminum Oxide (pages 320–321)

      Dr. Roland Rienäcker and Dr. Jürgen Graefe

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503201

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      Selective reactions of cyclic sesquiterpenes such as (+)-calarene 1 are achieved with catalysts formed from 2–10% potassium or sodium and basic Al2O3. Besides isomerization, e.g., to (–)-aristolene 2, the catalysts can also effect dehydrogenations.

    9. Torsional Isomerism in Metallocenes: Hindered Cp-Rotation in (s-cis-η-Butadiene)-bis(η-tert-butylcyclopentadienyl)zirconium (pages 321–323)

      Priv.-Doz. Dr. Gerhard Erker, Dipl.-Chem. Thomas Mühlenbernd, Dr. Reinhard Benn, Dr. Anna Rufińska, Dr. Yi-Hung Tsay and Prof. Dr. Carl Krüger

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503211

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      Three isomers of the title compound, a butadiene-zirconocene with tert-butyl substituents, could be identified at 310 K by NMR spectroscopy. In contrast to metallocenes with unsubstituted cyclopentadienyl groups, the rotation of the tBuC5H4 groups is a high-energy process.

    10. Ethynebis(triphenylphosphane)nickel(0) (pages 323–324)

      Dr. Klaus R. Pörschke, Dr. Yi-Hung Tsay and Prof. Dr. Carl Krüger

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503231

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      The title compound 2 was synthesized as the first ethyne complex of nickel(0) that is stable at room temperature. Reaction of (Ph3P)Ni(C2H4)2 with ethyne affords the reddish brown complex 1, which reacts with additional ethyne and PPh3 to give yellow 2.

    11. Simple Synthesis of Stable Iminoboranes (page 324)

      Martin Haase and Prof. Dr. Uwe Klingebiel

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503241

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      Owing to the (Me3Si)3C group, the iminoborane 4 is stable for months at room temperature. The synthesis of 4 is achieved by reaction of the aminoborane 1 with tris(trimethylsilyl)methyllithium 2; the substitution product 3 eliminates Me3SiF above 60°C to give 4, which is polar according to its NMR spectrum.

    12. The First Isolated Carbonylation-Active σ-Carbamoylnickel Complex (page 325)

      Prof. Dr. Heinz Hoberg and Dr. F. Javier Fañanás

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503251

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      The new σ-carbamoylnickel iodide 1 is superbly suited for formation of CC bonds. 1 had been postulated as an intermediate in nickel-induced carbonylations, but never isolated. It exhibits high carbonylation activity in the reaction with CO and Et2NH to give the oxalic acid derivative 2. The Ni[BOND]C σ-bond in 1 is capable of undergoing addition to CC multiple bond systems; the allyl complex 3 is formed from 1 and allene.

    13. CC Bond Formation of Alkenes with Isocyanates on Ni0 Complexes—a New Synthesis of Acrylamides (pages 325–326)

      Prof. Dr. Heinz Hoberg, Dipl.-Chem. Klaus Sümmermann and Armin Milchereit

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503252

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      The first metal-induced synthesis of an acrylic acid derivative 4 from a non-activated alkene 1 and an isocyanate 2 takes place via CC coupling to give an azanickelacyclopentanone 3. 4 is immediately formed upon heating 3.

    14. Dimerization of a C2B3-closo-Carbaborane(5) to the C4B6-Adamantane and its 2z/3z Valence Isomerization to the C4B6-nido-Carbaborane(10) (pages 326–328)

      Prof. Dr. Roland Köster, Günter Seidel and Dr. Bernd Wrackmeyer

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503261

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      The competition between classical and nonclassical structures of compounds of the type C4BnRn+4 is supported for the first time by experimental evidence. Whether the dimerization of 1 leads to the C4B6-adamantane derivative 2 or to the C4B6-nido-carbaborane(10) 3 is determined by the substituents on the C atoms equation image

    15. Crystal and Solution Structures of [tBu2C[DOUBLE BOND]NLi·O[DOUBLE BOND]P(NMe2)3]n (pages 328–329)

      Dr. Donald Barr, Dr. William Clegg, Dr. Robert E. Mulvey, Dr. David Reed and Dr. Ronald Snaith

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503281

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      The first dimeric lithium alkylideneamide with a μ2-nitrogen ligand and resulting Li2N2 ring is the solvent-stabilized title compound 1. The ring is exactly planar. Both the dimer 1 and the monomer are present in aromatic solvents, as was confirmed by cryoscopic Mr determinations in combination with high-field 1H- and 7Li-NMR measurements.

    16. Activation Energy of the Racemization of Optically Active Tricarbonyl(tropone)iron Complexes (pages 329–330)

      Dr. Akio Tajiri, Dr. Noboru Morita, Prof. Toyonobu Asao and Prof. Masahiro Hatano

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503291

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      Following HPLC resolution of the enantiomers of 1 and 2, the activation energy for the racemization of 1 was determined to be 25.8 kcal/mol by circular dichroism measurements. 2 does not racemize under the same conditions, since, in this case, an intermolecular process would be required.

    17. Intramolecular [4 + 2]-Cycloreversion of the Two Symmetrical Homobasketenes (pages 331–332)

      Dr. Wolfram Grimme, Dr. Wolfgang Mauer and Dipl.-Chem. Christian Sarter

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503311

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      The strain energy of the educts and the aromaticity of the products are the driving force for the [4 + 2]-cycloreversion of the homobasketene 1. The tricyclic intermediate 2 decomposes to benzene and cyclopentadiene. The free energy of activation for the decomposition of basketene and its homologues is proportional to the loss of strain energy.

    18. A New Class of Tantalum(V) Dithiolate Complexes: Synthesis and Characterization of [Ta(η5-C5Me4R)(SCH[DOUBLE BOND]CHS)2] (R = Me, Et) and [Ta(η5-C5Me5)(SCH2CH2S)2] (pages 332–333)

      Dr. Kazuyuki Tatsumi, Junko Takeda, Yoitsu Sekiguchi, Masaki Kohsaka and Prof. Akira Nakamura

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503321

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      The tantalum complex 1 is conformationally very flexible; an inversion of the five-membered TaS2C2 chelate ring takes place. The structure of 1 can be explained on the basis of MO considerations. Transition-metal thiolate complexes are interesting because of their biological and catalytic significance.

    19. Complete Signal Assignment of the 13C-NMR Spectra and Structure Determination of Corrinoids by 2D-INADEQUATE and 2D 13C, 1H-NMR Chemical Shift Correlation Using nJ(C,H) (pages 333–335)

      Dr. Reinhard Benn and Dr. Richard Mynott

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503331

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      The structure determination of corrinoids by two-dimensional NMR techniques has proven to be quick and reliable. Thus, the NMR signals of all 52 nonequivalent carbon atoms of the heptamethyl cobyrinate 1 can be assigned. These resonances are spread out over a region of more than 17 kHz; the coupling constants 1J(C,C) lie between 30 and 80 Hz.

    20. 13C-NMR Spectroscopy of Mixed Dialkylzinc Compounds with Prochiral Alkyl Residues (pages 335–336)

      Dr. Richard Mynott, Ing.-Grad. Barbara Gabor, Prof. Herbert Lehmkuhl and Dipl.-Chem. Ingo Döring

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503351

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      The disputed existence of dialkylzinc compounds containing two different alkyl groups has now been established for 1. A 1 : 1 mixture of sBu2Zn and iPr2Zn exhibits additional 13C-NMR signals. The differing signals for C6′ and C6″ of 1 confirm that the group iPrZn is bonded to a chiral residue.

    21. Chiral Copper(II) Complexes for the Enantioselective Resolution of DL-Dansyl-Amino Acids by HPLC (pages 336–337)

      Prof. Dr. Rosangela Marchelli, Dr. Arnaldo Dossena, Prof. Dr. Giuseppe Casnati, Prof. Dr. Francesco Dallavalle and Dr. Shulamith Weinstein

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503361

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      Insight into the nature of the interactions that are important for chiral recognition is provided by the ligands of the copper(II) complex 1 (R [DOUBLE BOND] C6H5CH2, (CH3)2CH, CH3; n = 2, 3). The ligands were synthesized in order to correlate the structure and stability of their copper(II) complexes with the ability of the complexes to resolve DL-dansyl-amino acids.

    22. On the Role of Radical Ion Pairs in [4 + 2] Cycloadditions (pages 337–339)

      Dr. Mechthild Dern, Dr. Hans-Gert Korth, Dipl.-Chem. Gebhard Kopp and Prof. Dr. Reiner Sustmann

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503371

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      The radical ions that have been postulated as intermediates in the Diels-Alder reaction could be detected spectroscopically in the reaction of the diene 1 with tetracyanoethylene (TCNE). The radical ion pair 2 is also formed when the adduct 3, which precipitates as colorless crystals from a deep-colored solution, is redissolved in tetrahydrofuran.

    23. Sealing and Opening Porous Monolayer Vesicle Membranes (pages 339–340)

      Prof. Dr. Jürgen-Hinrich Fuhrhop, Dipl.-Chem. Ulrich Liman and Dipl.-Chem. Hans Hermann David

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503391

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      A sealed vessel of molecular dimensions, which can be opened upon acidification, is formed by a synthetic vesicle whose pores can be reversibly sealed with a “stopper” 1. A prerequisite for the sealing was the use of a membrane composed of an uncharged bolaamphiphile and the pore-forming monensin pyromellitate.

    24. A New, Facile Route to 2-Azaallenium Salts—Bis(2-adamantylidene)ammonium Hexachloroantimonate (pages 340–341)

      Priv.-Doz. Dr. Ernst-Ulrich Würthwein, Dipl.-Chem. Rainer Kupfer, Dr. Peter H. M. Budzelaar, Dipl.-Chem. Cornelia Strobel and Prof. Dr. Horst P. Beck

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503401

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      A double isocyanate reaction affords the title compound 1, the first pure, alicyclic, substituted 2-aza-allenium salt. An X-ray structure determination was carried out on 1. 2-Aza-allenium salts have been proposed as intermediates in SNl reactions.

    25. Stable Triaziridines (pages 341–342)

      Prof. Dr. Gerd Kaupp, Dr. Oswald Dengler, Prof. Dr. Klaus Burger and Dipl.-Chem. Silvia Rottegger

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503411

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      Irradiation of the azimine 1 yields the triaziridines 2, which are stable up to 80°C and can therefore be distilled. Their stability makes it possible to carry out physical studies on this interesting small-ring system. Above 100°C, the triaziridines 2 decompose to the azimines 1 and 3.

    26. Reductive Alkylation of Bituminous Coal: Coal-Propanesulfonic Acids Having Remarkable Solubilities (pages 342–344)

      Priv.-Doz. Dr. Matthias W. Haenel, Ing.-Grad. Udo-Burckhard Richter and Heribert Hiller

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503421

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      Very water-soluble coal derivatives 2, R [DOUBLE BOND] H or Na, were prepared as shown below. In 2, the original structure of the coal is largely retained; most likely, the benzylic C atoms are alkylated.

    27. (CH3)2NSFmath imageAsFmath image–Synthesis and Stability of a Simple Pentacoordinated Sulfur(VI) Cation (pages 344–345)

      Dipl.-Chem. Thomas Meier and Prof. Dr. Rüdiger Mews

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503441

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      The relationship between sulfur(VI) cations and the isoelectronic phosphoranes is shown by their largely similar structures and bonding. In the cation 1 of the title compound, synthesized for the first time, sulfur displays the expected trigonal-bipyramidal coordination.

    28. Coupling of 3-Diazo-3H-pyrazoles with 2-Alkoxy-1,6-methano[10]annulenes and Oxidative Cyclization to Pyrazolotriazines (pages 346–347)

      Prof. Dr. Richard Neidlein, Dipl.-Chem. Uwe Jäschke, Priv.-Doz. Dr. Alfred Gieren, Dr. Gabriela Weber and Dipl.-Chem. Thomas Hübner

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503461

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      The functionalization of 1,6-methano[10]annulenes is achieved by reaction with diazonium-substituted heterocycles. Azo dyes, which can be cyclized oxidatively to 1, are obtained from the title compounds under mild conditions.

    29. Cationic Allylruthenium Complexes via Interchange of Allyl Moieties (pages 347–348)

      Dr. Faouzi Bouachir, Dr. Bruno Chaudret, Dr. Denis Neibecker and Dr. Igor Tkatchenko

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503471

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      The cationic ruthenium complex 1 is suited as a precatalyst for the dimerization and polymerization of unsaturated substrates. It also catalyzes the isomerization and hydrogenation of alkenes. The mechanism of formation of 1 has been elucidated; the most important step is an allyl group exchange.

    30. Strongly Preferential Alkylation and Carbonyl Olefination of α- and β-Hydroxycarbonyl Compounds by Organo-Transition Metal Reagents in Competition Experiments with the Corresponding Deoxy Compounds (pages 348–350)

      Prof. Dr. Thomas Kauffmann, Thomas Möller, Heidi Rennefeld, Siegfried Welke and Dipl.-Chem. Raphael Wieschollek

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503481

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      The reagents Cl2Cr[BOND]CH3, (iPrO)3Ti[BOND]CH3, and ClMo(O)[DOUBLE BOND]CH2 can distinguish between α- and β-hydroxyketones and “normal” ketones. As shown by competition experiments, the hydroxyketones are methylated or olefinated appreciably faster than the ketones without a hydroxy group.

    31. Isolation of the (E)-Enols of β-Ketocarboxylic Acid Derivatives (pages 350–351)

      Prof. Dr. Herbert Meier, Dipl.-Chem. Wolfgang Lauer and Dr. Friedrich Ulrich Scholter

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503501

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      The first examples of (E)-enols of β-dicarbonyl compounds are provided by the isolation of the methyl ester, X = OMe, and the morpholide, X = NC4H8O. Their melting points as well as their IR and NMR spectra differ clearly from those of the (Z)-isomers, which were also isolated.

    32. Hexaphosphabenzene as Complex Ligand (pages 351–353)

      Prof. Dr. Otto J. Scherer, Dipl.-Chem. Helmut Sitzmann and Dr. Gotthelf Wolmershäuser

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503511

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      Hexaphosphabenzene, P6, long a goal of chemical synthesis, has been obtained for the first time as a complex-stabilized ligand. The triple-decker sandwich complex 1 forms air-stable, amber-colored crystals. According to an X-ray structure analysis, the aromatic P6 ring is planar and lies parallel to the two five-membered rings.

    33. Carbonyliron-Assisted Coupling of Cyclopolyenes with Methyl Acrylate (pages 353–354)

      Dr. Richard Goddard, Dr. Friedrich-Wilhelm Grevels and Rosemarie Schrader

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198503531

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      The preparation of Fe(CO)3-complexed cyclic polyenes with C3 side chains was achieved as follows: the polyenes were allowed to react photochemically with [(η2-acrylic ester)Fe(CO)4] or in the dark with [(η2-acrylic ester)2Fe(CO)3]. The CC bond formation may be followed by an H shift from the side chain to the ring (cycloheptatriene [RIGHTWARDS ARROW] 1,) or vice versa (1,3-cyclohexadiene [RIGHTWARDS ARROW] 2).

  3. Book Reviews

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

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