Angewandte Chemie International Edition in English

Cover image for Vol. 29 Issue 8

August 1990

Volume 29, Issue 8

Pages 823–938

Currently known as: Angewandte Chemie International Edition

    1. Cover Picture (Angew. Chem. Int. Ed. Engl. 8/1990)

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008231

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      The cover picture shows the structure of a hemisphere of the cluster shell {V18O42} with effective ionic radii and view along the virtual S8-axis. The central iodide ion (violet) in this negatively charged cage is surrounded by 18 vanadium atoms (blue) and 24 oxygen atoms (red). In place of the iodide, an ion with distinctly smaller radius, e.g. chloride or bromide, can also be encapsulated. The 18/24 spherical shell apppears to be of general significance for such encapsulations, the oxygen atoms being able to form both one of the 13 Archimedean solids as well as the so-called 14th Archimedean solid. More about the preparation and structure of such hollow spherical compounds with the amazing property of being able to encapsulate negative ions is reported by A. Müller et al. on p. 926.

  1. Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Correspondences
    1. Syntheses, Conformations and X-Ray Structure Analyses of the Saccharide Chains from the Core Regions of Glycoproteins (pages 823–839)

      Prof. Dr. Hans Paulsen

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008233

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      In the binding protein-regionN-glycoproteins, like O-glycoproteins, have especially invariant oligosaccharide chains, which are referred to as core regions (core pattern of the N-glycoproteins shown on the right) It has been possible with the help of improved synthetic methods to prepare complex core-saccharides containing up to eleven sugar units. Structure determinations on such oligosaccharides by 2D-NMR spectroscopy and X-ray diffraction analysis can contribute to an elucidation of the function of the glycoproteins.

    2. Nonmolecular Metal Chalcogenide/Halide Solids and Their Molecular Cluster Analogues (pages 840–856)

      Sonny C. Lee and Prof. Richard H. Holm

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008401

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      The excision of clusters from the solid-state phase has proven to be an excellent method for the synthesis of novel molecular clusters. Thus, e.g., cuboidal Mo3S4 clusters can be excised from the polysulfide Mo3S7Cl4, which is characterized by zig-zag chains of Cl2-bridged Mo3(S2)3S clusters (see Figure). The central theme of this review article further concerns the systematic correlation of solid-state structures with molecular cluster analogues.

    3. Interfaces between Molecular and Polymeric “Metals”: Electrically Conductive, Structure-Enforced Assemblies of Metallomacrocycles (pages 857–879)

      Prof. Tobin J. Marks

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008571

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      The design, synthesis, characterization and understanding of new molecular and macromolecular substances exhibiting “metal-like” electrical properties have represented an active area of research at the interface of chemistry, physics and materials science for ca. 15 years. Phthalocyaninatometal complexes have proven to be excellently suitable for transformation by crystallizatiominto molecular stacks and by condensation polymerization into stacked polymers. Reductive or oxidative doping (shown schematically on the right) renders both materials electrically conducting.

  2. Communications

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Correspondences
    1. Novel Platinum Complexes Enable Selective C-H and C-Si Activation of Tetramethylsilane at Room Temperature (pages 880–882)

      Prof. Dr. Peter Hofmann, Dipl.-Chem. Helmut Heiss, Dipl.-Chem. Peter Neiteler, Prof. Dr. Gerhard Müller and Dipl.-Chem. Joachim Lachmann

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008801

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      No C[BOND]H activation of benzene, but a selective C[BOND]Si activation of tetramethylsilane (TMS) characterizes the reactivity of the coordinative and electronically highly saturated, “hot” Pt0-complex 2, which is formed from the cis-hydridoneopentyl complex 1 at room temperature by elimination of neopentane. 2 can be detected by trapping reactions; reaction with TMS at room temperature leads quantitatively to the methyl(trimethylsilyl)-complex 3, which is also formed by intramolecular rearrangement of the independently synthesized hydride complex 4.

    2. Heteronuclear “X-Y” Decoupling in the MAS-NMR Spectroscopy of Inorganic Solids (pages 882–884)

      Robert Maxwell, David Lathrop, Deanna Franke and Prof. Dr. Hellmut Eckert

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008821

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      31P-spin decoupling in 113Cd- and 77Se-NMR spectroscopy leads to considerable signal sharpening, as could be demonstrated, for example, with the semiconductor CdGeP2 and the ionic conductor Ag7PSe6. Sample rotation at the magic angle (MAS) and simultaneous irradiation of the 31P resonance frequence furnished, in the case of CdGeP2, the highly resolved 113Cd-NMR spectrum pictured on the right.

    3. Hydrogenobyrinic Acid: Isolation, Biosynthesis, and Function (pages 884–886)

      Dr. Francis Blanche, Denis Thibaut, Denise Frechet, Marc Vuilhorgne, Dr. Joel Crouzet, Béatrice Cameron, Dipl.-Biol. Kersten Hlineny, Dipl.-Chem. Ute Traub-Eberhard, Dipl.-Chem. Maureen Zboron and Dr. Gerhard Müller

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008841

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      The cobalt-free analogue of the vitamin- B12 parent substance cobyrinic acid 2, the hydrogenobyrinic acid 1, has been made available by a biosynthetic method. This opens up new possibilities for studies on the biosynthesis of 1 and 2 as well as on their chemistry. The first investigations on the biosynthesis and function of 1 are reported; and a complete assignment of the 1H- and 13C-NMR signals of 1 is given.

    4. Application of the Combined ab initio/IGLO/NMR Method to Resolve the B6H12 Structural Question (pages 886–888)

      Dipl.-Chem. Michael Bühl and Prof. Dr. Paul von Ragué Schleyer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008861

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      Reliably checking, or even possibly in some cases replacing the need for experiment is a facility of the combined ab initio/IGLO/ NMR method being increasingly applied for the solution of complex structural questions. The method throws doubt on the structure assigned to B6H12 (1) on the basis of gasphase electron diffraction (GED), as the alternative, calculated (MP2/6-31G*) structure shown in the figure, results in calculated 11B-NMR shifts which more closely match experimentally observed chemical shifts than those calculated using the GED structure.

    5. Surprising Basicity of Low Valent Transition Metal Carbonyl Fluorides; Crystallographic Characterization of an sp2-CHF Hydrogen Bond (pages 888–890)

      Dr. Carolyn E. Osterberg, Dr. Margaret A. King, Dr. Atta M. Arif and Prof. Thomas G. Richmond

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008881

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      Realization of molecular recognition with transition metal complexes via exploitation of C[BOND]HF[BOND]M and/or O[BOND]HF[BOND]M hydrogen bonds—this aim is approached by the result that was observed with the WII-complex 1, which proves to be a surprisingly strong Lewis base that binds 4-chlorophenol equally as well as pyridine. The solid-state packing of an analogue of 1 fluorinated in the aryl ring is characterized by hydrogen bonds between imine-CH and fluoroligands.

    6. O-Atom Insertion into Si[BOND]H Bonds by Dioxiranes: A Stereospecific and Direct Conversion of Silanes into Silanols (pages 890–891)

      Prof. Dr. Waldemar Adam, Dr. Rossella Mello and Prof. Dr. Ruggero Curci

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008901

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      The synthesis of silanols 2 from the corresponding silanes 1 is especially easy, if the latter are allowed to react with dimethyl or methyl(trifluoromethyl)dioxirane (1–18 min reaction time, quantitative yields of enantiomerically pure product after removal of the solvent). The experimental data are consistent with an oxene mechanism (R1[BOND]R3 = alkyl, aryl).

    7. Synthesis and Molecular Structure of cis-[Pd(C6F5)2(C6H5CH2Nme2)], an Intramolecular Coordination Compound Containing an Unusual η1-Arene Ligand (pages 891–893)

      Dr. Larry R. Falvello, Prof. Juan Forniés, Dr. Rafael Navarro, Dr. Violeta Sicilia and Dr. Milagros Tomás

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008911

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      Benzyldimethylamine as C,N-chelate ligand in which, in addition, the phenyl ring is η1-coordinated; this is the surprising feature of the structure of the title complex (right: section without C6F5 ligands). The Pd[BOND]C7 distance (2.335(7) Å) is greater than a Pd[BOND]C σ-bond, but smaller than that in an η2-arene-Pd complex. Despite η1-coordination, the phenyl ring is planar, and all C[BOND]C bond lengths and C[BOND]C[BOND]C angles are equal. Possibly the complex has model character for intermediates in orthometalations.

    8. Bis(pentamethylcyclopentadienyl)silylene as Ligand in Gold(I) Chloride Complexes (pages 893–894)

      Prof. Dr. Peter Jutzi and Dr. Andreas Möhrke

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008931

      The first real silylene complex was obtained by reaction of decamethylsilicocene 1 with carbonylgold(I) chloride. To reduce the electron deficit at the silicon in 2, one of the two cyctopentadienyl ligands remains π-bonded. The deep-red silylene complex 2 resembles the Fischer carbene complexes. Addition of pyridine or tert-butyl isocyanide leads to the donor-stabilized silylene complexes of the type (Me5C5)2Si(donor)–AuCl, in which both cyclopentadienyl ligands are σ-bound.

      • equation image
    9. Ytterbium(II) Benzamidinates, a New Class of Highly Reactive Lanthanoid(II) Complexes (pages 894–896)

      Michael Wedler, Dr. Mathias Noltemeyer, Ursula Pieper, Hans-Georg Schmidt, Dr. Dietmar Stalke and Dr. Frank T. Edelmarin

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008941

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      Good solubility and high reactivity characterize the readily accessible ytterbium benzamidinates 1 (R = H, OMe). Their strong reducing action can be exploited for the synthesis of novel lanthanoid(III) complexes with “soft” chalcogenolato ligands.

    10. Oxidative Addition of Phosphorus Ylides to Ru3(CO)12 (pages 896–898)

      Dr. D. Scott Bohle, Dipl.-Chem. Daniel Heineke, Prof. Antonio Tiripicchio, Prof. Marisa Tiripicchio Camellini and Prof. Dr. Heinrich Vahrenkamp

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008961

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      The Ru3C-cluster 1 with a C-bonded phosphane ligand is the final product of the reaction of Ph3P[DOUBLE BOND]CH2 with Ru3(CO)12. This cluster could be structurally characterized, as also could a phosphonio enolate isolated as intermediate. The formation of 1 completes the use of all methane H-atoms in the sequence CH4 [RIGHTWARDS ARROW] CH3I [RIGHTWARDS ARROW] CH2 = PPh3 [RIGHTWARDS ARROW] 1.

    11. Functional Tetrahedral Zinc Complexes (pages 898–899)

      Dipl.-Chem. Ralf Alsfasser, Dr. Anne K. Powell and Prof. Dr. Heinrich Vahrenkamp

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008981

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      A hydrophobic pocket is formed by the residues R(Ph, tBu) in the zinc compounds L3Zn–X 1, X = NOmath image, CHmath image and C2H5S. The first unequivocally characterized hydroxocomplex of zinc [L3Zn[BOND]OH[BOND]ZnL3](ClO4)3, L = tert-butylpyrazole anion, was formed by hydrolysis, presumably via the intermediate cation with X = H2O. In the four complexes the whole hard/soft scale is covered with respect to the ligand X. There are structural relationships to the active centers of zinc-containing enzymes.

    12. A 1,2:2,1-Bis(2-silapropane-1,3-diyl)diborane(6): Stabilization Product of Bis(trisyl)diborane(2)? (pages 899–900)

      Theo Mennekes, Prof. Dr. Peter Paetzold and Dr. Roland Boese

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199008991

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      A first indication of the occurrence of an organic derivative of diborane(2), HB[DOUBLE BOND]BH, as intermediate is provided by the unexpected constitution of the structurally characterized product 1 of the reaction of (Me3Si)3CBCl2 with Na/K alloy. It may be assumed that (Me3Si)3C(Cl)B[BOND]B(Cl)C(SiMe3)3 or (Me3Si)3CB: are initially formed and then react further to give the B[DOUBLE BOND]B system. A stabilization by C[BOND]H-additions at the reactive double bonds would be the final step.

    13. Boroboration of CO with Tri-tert-butylazadiboriridine (pages 900–902)

      Prof. Dr. Peter Paetzold, Burkhard Redenz-Stormanns and Dr. Roland Boese

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009001

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      The formation of the unexpected, exotic product 2 in the reaction of the sterically shielded Hückel-aromatic three-membered ring compound 1 can plausibly be. explained by way of analogy. With CO from Fe(CO)5, a completely different, likewise unexpected product is obtained, whose formation involves cleavage of the C[TRIPLE BOND]O triple bond, and even at −30°C! Both results throw valuable light the reactivity of CO.

    14. The First Clamped and Strongly Deformed Adamantane (pages 902–904)

      Prof. Dr. Fritz Vögtle, Dipl.-Chem. Joachim Dohm and Dr. Kari Rissanen

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009021

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      Adamantane provides a universal building lock for the replacement of benzene rings in trained ring compounds. This is found in the synthesis of the adamantanophane “1”, whose bond angles and bond lengths, according to an X-ray structure analysis, differ considerably from those of the free adamantane. One of the two intraannular aliphatic hydrogen atoms (Hi) penetrates deep into the π-electron sphere of the boat-shaped, deformed benzene ring and is thus shifted strongly up-field (δ = −0.10!).

    15. CsNa2(OH)3 · 6H2O: Structural Differentiation in the Hydrate of a Ternary Alkali-Metal Hydroxide (pages 904–905)

      Prof. Dr. Dietrich Mootz and Dipl.-Chem. Heinz Rütter

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009041

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      Differentiation, both between the various large cations as well as between the H2O molecules and OH ions characterizes the crystal structure of CaNa2(OH)3·6H2O (right: central projection along the b axis). The Na ions are coordinated by six H2O molecules in a distorted octahedral geometry. The octahedra are linked by common faces to form columns which are arranged in a close packed pattern of cylindrical rods, and are connected to each other by a complex system of hydrogen bridges.

    16. C4O2 (1,2,3-Butatriene-1,4-dione), the First Dioxide of Carbon with an Even Number of C Atoms (pages 905–908)

      Prof. Dr. Günther Maier, Dr. Hans Peter Reisenauer, Prof. Dr. Heinz Balli, Dipl.-Chem. Willy Brandt and Prof. Dr. Rudolf Janoschek

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009051

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      Photolysis of the diazaketones 1 or 2 in an argon matrix affords access to butatrienedione 3, which is readily cleaved photochemically into C3O and CO. So far it has not been possible to clarify, either experimentally or computationally, whether 3 has a triplet or a singlet ground state.

    17. Identification of Butatrienedione, Its Radical Anion, and Its Radical Cation in the Gas Phase (pages 908–909)

      Dipl.-Chem. Detlev Sülzle and Prof. Dr. Helmut Schwarz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009081

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      Butatrienedione is also detectable mass spectroscopically: electron impact ionization of 1 affords, via elimination of CO2 and Me2CO, the radical anion OC4O•⊖, which can be converted by vertical charge reversal into the corresponding cation. In neutralization-reionization experiments, starting from both species it was possible to obtain the neutral molecule.

    18. Iron(II)-Mediated Hydride and Methanide Transfer to Carbonyl Groups (pages 910–912)

      Dipl.-Chem. Detlef Schröder and Dipl.-Chem., Prof. Dr. Helmut Schwarz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009101

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      In the Fe-mediated Meerwein-Ponndorf-Verley-Oppenauer reaction in the gas phase the following is noteworthy: besides the conventional hydride transfer, an analogous methanide migration has been detected for the first time. In contrast, in the case of sterically crowded alkoxides such as 1 a β-CH3 rearrangement takes place.

    19. Unsaturated C3B2 Rings with Neighboring Boron Atoms: Derivatives of 4-Methylene-1,2-dibora-cyclopentane, Dilithium 2,3-diboratafulvene, and 1,2-Dibora-3-yclopentene (pages 912–913)

      Prof. Dr. Gerhard E. Herberich, Dipl.-Chem. Christian Ganter, Dr. Lars Wesemann and Dr. Roland Boese

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009121

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      Among the unsaturated B[BOND]C heterocycles, those with B[BOND]B groups in the ring are especially difficult to synthesize. By borylation of the trimethylenemethane dianion and reaction of the product with HCl it has now been possible to synthesize the first 1,2-C3B2 compounds 13. Compound 1, R = iPr, has an unusual twist conformation in the Crystal. Metalation of 1 with bulky, strong bases affords 3,4-diboratafulvenes 2; their protonation with cyclopentadiene yields 4-methyl-1,2-dibora-3-cyclopentane derivatives 3, R = Et,iPr.

    20. Low-Dimensional Compounds Incorporating Polychalcogenide Ligands. The Unusual Polymeric Structures of [AuSe5]math image and [AuSe13]math image (pages 914–915)

      Younbong Park and Prof. Mercouri G. Kanatzidis

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009141

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      With short Au…Au contacts of 2.9 Å, the “dimeric” structure of the polymeric [AuSe5] anion 1 in KAuSe5 provides a further example of d10–d10 interactions in the solid state. KAuSe5 is formed as reddish-brown, needlelike crystals from a polychalcogenide melt (K2Se: Au:Se = 2:1 :8); if the amount of K2Se is reduced to 1.8, K3AuSe13 is formed.

    21. Biomimetic Catalysis of an SN2 Reaction Resulting from a Novel Form of Transition-State Stabilization (pages 915–918)

      Dr. David A. Stauffer, Richard E. Barrans Jr. and Prof. Dennis A. Dougherty

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009151

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      A cation – π-electron interaction is the essential factor responsible for the stabilization of the transition state during the methylation of quinoline (and related bases) with methyl iodide by a cage host compound (see picture on the right). The stabilization results in a catalytic effect: In the presence of the host the reaction is accelerated by a factor of 100. The system provides a primitive model for enzymatic methylation.

    22. 1,2-Dimethyl-1,2-disila-closo-dodecaborane(12), the First Silicon Analogue of an ortho-Carborane (pages 918–919)

      Prof. Dietmar Seyferth, Dr. Klaus Büchner, Dr. William S. Rees Jr. and Dr. William M. Davis

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009181

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      The carborane homologous, icosahedral o-disilaborane 1 is formed together with other products upon reaction of B10H14 with bis(dimethylamino)(methyl)silane in boiling benzene. The Si[BOND]Si distance of 2.308(2) Å would suggest that the Si2-unit in 1 may formally be regarded as a doubly bridged disilyne MeSi[TRIPLE BOND]SiMe. 1 is air-stable and inert toward acids; in KOH solution, however, it decomposes within minutes.

    23. Helicene Dianions: Paratropicity of Twisted Phenanthrene Dianions (pages 919–921)

      Dipl.-Chem. Ron Frim, Prof. Dr. Albrecht Mannschreck and Prof. Dr. Mordecai Rabinovitz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009191

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      Non-planar, alkyl-substituted phenanthrenes are reduced to the dianions 1a–c with metallic lithium and sodium in [D8]THF. The paratropic chemical shifts in the 1H-NMR spectrum and the linewidths of the signals of all dianions depend in the same way on the angle of twist: the greater the twist, the better the resolution of the 1H-NMR signals and the smaller the upfield shifts.

    24. Correlations between Magnetism and Structure in Dinuclear CuIIFeIII Complexes with Integer Spin EPR Signals (pages 921–923)

      Theodore R. Holman, Kevin A. Andersen, Prof. Oren P. Anderson, Michael P. Hendrich, Carlos Juarez-Garcia, Prof. Eckard Münck and Prof. Lawrence Que Jr.

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009211

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      The FeIII and the CuII-atom in the complexes 1 and 2 shown below are antiferromagnetically and ferromagnetically coupled, respectively. This difference in the coupling interaction can be correlated with the orientation of the orbital at CuII responsible for the magnetism relative to the bridging phenolate O-atom. L = 2 6-bis[(bis(2-pyridylmethyl)amino(methyl))]-4-methylphenol.

    25. Torand Synthesis by Trimerization—New Receptors for Guanidinium (pages 923–925)

      Prof. Thomas W. Bell and Jia Liu

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009231

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      The largest cycloarene derivative reported so far, the torand 1, is surprisingly readily accessible by CsOH-mediated cyclotrimerization. According to Macromodel calculations, 1 is almost planar and binds guanidinium with formation of six almost ideal hydrogen bonds with only slight change in conformation: the UV spectra of the torand and of its guanidinium complex are almost identical.

    26. Topologically Interesting Cages for Negative Ions with Extremely High “Coordination Number”: An Unusual Property of V-O Clusters (pages 926–927)

      Prof. Dr. Achim Müller, Dipl.-Chem. Michael Penk, Dipl.-Chem. Ralf Rohlfing, Erich Krickemeyer and Dipl.-Chem. Joachim Döring

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009261

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      Negatively charged ions with significantly different radii, e.g. Cl, Br and I, can be encapsulated as guest molecules in V[BOND]O-cluster shells such as {V18O42} 1. According to X-ray structure analyses the encapsulated ions are fixed in the center of 1 and are surrounded by 18 V atoms and 24 O atoms. The distance from the center of the cluster to the O and V atoms of the periphery is on average 367.5 and 375.0 pm, resp. (V = black, O = white).

    27. A 1,6-Diphospha-1,2,4,5-hexatetraene, Synthesis and Ring Closure Reactions to Cyclobutenes (pages 927–929)

      Prof. Dr. Gottfried Märkl, Dipl.-Chem. Peter Kreitmeier, Prof. Dr. Heinrich Nöth and Dr. Kurt Polborn

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009271

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      By oxidative coupling of the lithiated allene 1, the title compound 2 is formed in several stereoisomeric forms. One of them cyclizes rapidly in a conrotatory ring closure to give 3, another cyclizes slowly to give 4, which was characterized by an X-ray structure analysis. Aryl = 2,4,6-tBu3C6H2.

    28. The Azide Homologues Et[BOND]PPP and Ph[BOND]AsAsAs as Bifacially Coordinated Ligands in Tripod-Cobalt Complexes: Synthesis, Structure and Molecular Dynamics (pages 929–931)

      Dipl.-Chem. Annette Barth, Prof. Dr. Gottfried Huttner, Dipl.-Chem. Martin Fritz and Dr. Laszlo Zsolnai

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009291

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      What should they be called, the higher homologues of azides: phosphides and arsides? Hardly, and even the 1990 recommendations of the Inorganic IUPAC rules do not help very much further. Research is often one step ahead of nomenclatural canonization, as is demonstrated by the synthesis of the PhAs3 complex cation 1 and an EtP3 analogue. 1 is formed upon reaction of Co(BF4)2 · 6H2O with PhAsH2 in the presence of H3CC(CH2PPh2)3 (= L) and can be isolated as the BFmath image salt (blackish-green crystals).

    29. A Novel Synthesis of 2-Aminomethyl-1,3-butadienes from N,O-Acetals (pages 932–933)

      Dipl.-Chem. Thomas Arenz and Priv.-Doz. Dr. Herbert Frauenrath

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009321

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      The synthesis of 2-aminomethyl-1,3-butadienes 3 can be achieved surprisingly easily, namely from unsaturated N,O-acetals 1 under the conditions of base-catalyzed C[DOUBLE BOND]C isomerization. β-Aminocarbonyl compounds 2 probably occur as intermediates, which are formed by a hovel variant of the intramolecular Mannich reaction.

    30. Imidazo[1,2-e][1,3,5]triazepine Derivatives: First Representatives of a New Heterocyclic System (pages 933–935)

      Prof. Dr. Gerd Kaupp and Dipl.-Chem. Klaus Sailer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009331

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      The novel tetraazaheterocycles 2 are obtainable in a one-pot process if the benzimidazole derivative 1 is allowed to react with RNH2 in anhydrous dichloromethane (room temperature, yield ca. 60%). The compounds 2 are potential precursors for tetraazaazulene cations and, because of their being related to pteridines, can be expected to display interesting biological activities (R = H, alkyl, aryl).

  3. Book Reviews

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

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Correspondences
    1. Correspondence (page 938)

      D. S. Bohle and H. Vahrenkamp

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199009381