Angewandte Chemie International Edition in English

Cover image for Vol. 35 Issue 19

October 18, 1996

Volume 35, Issue 19

Pages 2163–2267

Currently known as: Angewandte Chemie International Edition

    1. Cover Picture (Angew. Chem. Int. Ed. Engl. 19/1996)

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199621621

      Thumbnail image of graphical abstract

      The cover picture shows a novel rhodium(II) carbonyl hydrido complex, which is proposed as the active catalyst for regioselective hydroformylation, as well as sections from the 500 MHz 1 H NMR and 1H {31P} NMR spectrum of this compound in situ. The unusually large coupling constant of 164 Hz is not attributed to a trans-2J(P,H) coupling, but to a 1J(Rh,H) coupling. More about the behavior of this dinuclear rhodium complex is reported by Stanley et al. on p. 2253 ff.

  1. Reviews

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Book Reviews
    1. The Identification of Genes Controlling Development in Flies and Fishes (Nobel Lecture) (pages 2176–2187)

      Prof. Christiane Nüsslein-Volhard

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199621761

      Vertebrate genes can often be identified based on analogies to Drosophila genes. This homology has been important in advancing the understanding of vertebrate development on a genetic level, and indicates that a basic body plan is common to the vertebrates and arthropods. Comparisons of patterning in flies and vertebrates have been successful most recently in studies of zebra fish.

    2. From Molecular Patterns to Morphogenesis—The Lessons from Studies on the Fruit Fly Drosophila (Nobel Lecture) (pages 2188–2194)

      Prof. Eric Wieschaus

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199621881

      Establishing inbred lines from single flies carrying mutagenized chromosomes was the strategy behind the mutagenesis experiments conducted by E. Wieschaus and C. Nusslein-Volhard in Heidelberg. Within two generations, homozygous flies were obtained whose development was compared with that of their heterozygous siblings. The results from 27000 inbred lines led to first indications of the causes of early morphological changes in embryogenesis.

  2. Highlights

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Book Reviews
    1. Crystal Packing and Molecular Geometry (pages 2195–2197)

      Priv.-Doz. Dr. J. Jens Wolff

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199621951

      Thumbnail image of graphical abstract

      Despite recent progress, true crystal engineering remains an elusive goal. Subtle differences in energy, as in the rotamers of 1, may cause great differences in solid-state structures, and the influence of a crystalline environment on molecular parameters is even less well-understood. Successes and problems in the studies of the structures of molecular crystals are discussed.

    2. The Tricks of Ribosomal Elongation Factors (pages 2198–2201)

      Prof. Dr. Knud H. Nierhaus

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199621981

      The two universally existing ribosomal elongation factors ET-Tu and EF-G are archetypes of the large family of G-proteins, which regulate a plethora of processes in the cell according to a basic scheme. In the past few years the crystal structures elucidated for various conformations of the elongation factors have provided exciting insights into the functions of G-proteins and into the mechanism of protein biosynthesis.

  3. Communications

    1. Top of page
    2. Reviews
    3. Highlights
    4. Communications
    5. Book Reviews
    1. Programming a Hydrogen-Bonding Code for the Specific Generation of a Supermacrocycle (pages 2204–2206)

      Dr. Mark Mascal, Dr. Nicholas M. Hext, Dr. Ralf Warmuth, Dr. Madeleine H. Moore and Dr. Johan P. Turkenburg

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622041

      Thumbnail image of graphical abstract

      Infinite channels with a diameter 10.5 Å are formed by the DNA-base hybrid 1 in the solid state. These channels arise because 1 specifically communicates the hydrogen bonding codes of the nucleobases cytosine and guanine (“C” and “G”) to unambiguously assemble hexagonal, macrocyclic aggregates 16, which overlap in the crystal.

    2. A Neutral, Triple-Helical, Trinuclear, Oxo-Centered Mixed-Valence Iron Complex (pages 2206–2208)

      Prof. Dr. Rolf W. Saalfrank, Dipl.-Chem. Stefan Trummer, Dr. Harald Krautscheid, Dr. Volker Schünemann, Prof. Dr. Alfred X. Trautwein, Dr. Stefan Hien, Dipl.-Chem. Christian Stadler and Prof. Dr. Jörg Daub

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622061

      Thumbnail image of graphical abstract

      Reminiscent of a windmill, the novel triple-helicate [(FeIII)2FeIIOL3] 1, a neutral oxo-centered mixed-valence complex, is formed in a one-pot reaction by self-assembly. The pentadentate ligand L acts in a tritopic fashion and connects the three iron ions in a triangular plane. At the center of 1 lies μ3-O2- ion. The structural similarity of 1 with trinuclear carboxylatoiron complexes is striking.

    3. The First Metallacrown Ether Sandwich Complex (pages 2209–2210)

      Prof. Dr. Rolf W. Saalfrank, Dipl.-Chem. Norbert Löw, Dr. Frank Hampel and Prof. Dr. Hans-Dietrich Stachel

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622091

      Thumbnail image of graphical abstract

      New blood for crown ether chemistry! Beside the well-known organocrown ether sandwich complexes 1 there now exist topologically equivalent metallacrown ether complexes 2. These metallasandwich complexes are generated in a one-pot reaction by spontanous self-assembly and in one case have been unambiguously characterized by a crystallographic structure analysis.

    4. Highly Selective Epoxidation Catalysts Derived from Intrazeolite Trimethyltriazacyclononane-Manganese Complexes (pages 2211–2213)

      Dr. Dirk E. De Vos, Julia L. Meinershagen and Prof. Dr. Thomas Bein

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622111

      Thumbnail image of graphical abstract

      Adsorption of a cyclic amine ligand into a Mn-exchanged faujasite zeolite results in the formation of the corresponding amine—Mn complexes in the cavities of the zeolite. These “amine—Mn zeolites” are novel catalysts for the highly selective epoxidation of numerous olefins with H2O2. A computer model of a possible catalytically active species, a MnIII/MnIV complex with bridging oxygen ligands, is shown on the right.

    5. Toward the Design of Porous Organic Solids: Modular Honeycomb Grids Sustained by Anions of Trimesic Acid (pages 2213–2215)

      Rosa E. Melendez, Dr. C. V. Krishnamohan Sharma, Prof. Michael J. Zaworotko, Dr. Carey Bauer and Prof. Robin D. Rogers

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622131

      Thumbnail image of graphical abstract

      The trigonal symmetry of trimesic acid (1,3,5-benzenetricarboxylic acid) [H3TMA] is exploited in the generation of honeycomb grid solids that eschew interpenetration. The structures of [N,N-dicyclohexylammonium]3[TMA]· xMeOH and [N,N-dimethylammonium]12[H3TMA] · [H2TMA]3 · [HTMA2−]3·[TMA3−] reveal, relative to H3TMA, expanded and contracted honeycomb grids having internal cavities with effective diameters of 12.7 and 10.4 Å, respectively.

    6. Synthesis and Structure of the Nanoclusters [Hg32Se14(SePh)36], [Cd32Se14(SePh)36-(PPh3)4],[P(Et)2(Ph)C4H8OSiMe3]5- [Cd18I17(PSiMe3)12], and [N(Et)3C4H8OSiMe3]5[Cd18I17(PSiMe3)12] (pages 2215–2218)

      Dipl.-Chem. Silke Behrens, Dipl.-Chem. Marco Bettenhausen, Dr. Anne C. Deveson, Dr. Andreas Eichhöfer, Prof. Dr. Dieter Fenske, Almut Lohde and Dr. Ulrike Woggon

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622151

      Thumbnail image of graphical abstract

      Red crystals of 1 were obtained by treatment of HgII salts with PhSeSiMe3 in organic solvents. Depending on the starting materials and conditions, 1 crystallizes either in the cubic space group P23 or in the trigonal space group P32. The diameter of the cluster that crystallizes in the cubic space group is about 2400 pm (the framework of the Hg32Se50 cluster is depicted on the right). In addition, the other title compounds were prepared and isolated in the form of colorless crystals.

    7. The Mechanism of Class II, Metal-Dependent Aldolases (pages 2219–2221)

      Prof. Dr. Wolf-Dieter Fessner, Dr. Achim Schneider, Dipl.-Chem. Heike Held, Dr. Gudrun Sinerius, Dr. Christiane Walter, Mark Hixon and Prof. Dr. John V. Schloss

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622191

      Thumbnail image of graphical abstract

      Chelation of the cis-enediolate form of dihydroxyacetone phosphate (see picture on the right) is the key step in the mechanism of action of Zn2+-dependent aldolases. This proposal is derived from inhibition studies with model compounds for both ground and transition states and from an X-ray structure determination of a protein—ligand complex. The high degree of asymmetric induction occurring at both termini of the newly formed C[BOND]C bond can now be explained.

    8. The Design and Synthesis of a Scaffold for Combinatorial Chemistry Based on Bile Acid (pages 2222–2224)

      Dr. Günther Wess, Klaus Bock, Horst Kleine, Dr. Michael Kurz, Dr. Wolfgang Guba, Dr. Horst Hemmerle, Dr. Eloisa Lopez-Calle, Dr. Karl-Heinz Baringhaus, Dr. Heiner Glombik, Dr. Alfons Enhsen and Dr. Werner Kramer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622221

      Thumbnail image of graphical abstract

      A complete β-turn can be mimicked by the tetrapeptide mimetic 1, which can thus be built into peptides with unambiguous directionality. Mimetic 1 was prepared from chenodeoxycholic acid, and is very interesting as a building block for compound libraries of β-turn mimics. ℗ = polymer support.

    9. Synthesis and Crystal Structure of the [Ni32C6(CO)36]6− Hexaanion: An Extended Fragment of the M23C6 Lattice Stabilized in a Shell of Edge-Bridging Carbonyl Ligands (pages 2225–2226)

      Dr. Francesca Calderoni, Prof. Francesco Demartin, Dr. M. Carmela Iapalucci and Prof. Giuliano Longoni

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622251

      Thumbnail image of graphical abstract

      Delight from degradation and decomposition. The aesthetically pleasing [Ni32C6(CO)36]6− carbide cluster was obtained by the degradation of [Ni38C6(CO)42]6− under a CO atmosphere and by the thermal decomposition of [Ni10C2(CO)16]2−. Its structure, the metal-carbon core of which is shown on the right, consists of an extended fragment of the Cr23C6 lattice stabilized in a shell of edge-bridging carbonyl ligands.

    10. The Aluminocenium Cation [Al(C5H5)2]+: A Highly Effective Initiator for the Cationic Polymerization of Isobutene (pages 2226–2228)

      Prof. Manfred Bochmann and Dr. David M. Dawson

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622261

      Thumbnail image of graphical abstract

      One of the last hitherto unknown simple metallocenes, the aluminocenium cation [Al(η-C5H5)2]+1, is readily accessible from [AlCp2Me] and B(C6F5)3. The spectroscopic data are consistent with a metallocene structure. The complex is a highly efficient initiator for the carbocationic polymerization of isobutene and the industrially important copolymerization of isobutene and isoprene.

    11. From 1σ4, 2σ2 to 1σ4, 2σn-Diphosphetes (n = 3–6): The Surprising Persistence of the P[BOND]P bond (pages 2228–2230)

      Muriel Sanchez, Dr. Régis Réau, Dr. Françoise Dahan, Prof. Dr. Manfred Regitz and Dr. Guy Bertrand

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622281

      Thumbnail image of graphical abstract

      Without destruction of the four-membered ring skeleton, the σ2-phosphorus atom of a 1 σ4,2σ2-diphosphete can extend its coordination number up to six (as the series below shows)!

    12. Microporous Mixed Oxides—Catalysts with Tunable Surface Polarity (pages 2230–2233)

      Dr. Stephan Klein and Prof. Dr. Wilhelm F. Maier

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622301

      The surface polarity can be regulated for amorphous, microporous Si/Ti mixed-oxide catalysts during their variable, single-step, preparation procedure (sol—gel). In contrast to zeolites the surface of these catalysts is thus tunable to the polarity of the substrate. Oxidations of various substrates can be catalyzed selectively not only with hydrogen peroxide but also with organic peroxides; the highest conversions are obtained with catalysts that have optimized surface polarity.

    13. Isolation and Characterization of the Dimetallofullerene Ce2@C80 (pages 2234–2235)

      Junqi Ding and Prof. Shihe Yang

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622341

      Purer than the driven snow. Ce2@C80 has been isolated with a purity of >99% by an efficient extraction procedure, followed by an HPLC separation. The X-ray photoelectron spectrum of Ce2@C80 suggests that both Ce atoms inside the cage occur as Ce3+, in agreement with the results of a recent ab initio calculation.

    14. Heavy Element π Donation Is Not Less Effective (pages 2236–2238)

      Dipl.-Chem. Jürgen Kapp, Dr. Christian Schade, Dr. Ahmed M. El-Nahasa and Prof. Dr. Paul von Ragué Schleyer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622361

      The inherent stabilizing effects of lone pair substituents from the first five rows of the periodic table on carbocations depend primarily on the group rather than on the period, judging from high-level ab initio computations (QCISD(T)/DZ + + PP// MP2(fc)/DZ+P). When planarity is imposed on the pnictogen compounds, the stabilization energies from group 15 substituents are almost constant (ca. 95 kcal mol−1 from N to Sb, based on CHmath image) and exceed the stabilization energies of chalcogens (60-66 kcal mol−1, O <S ≈ Se <Te) and halogens (18-38 kcal mol−1, F<Cl≈Br<I).

    15. The First Demonstration of Molecular Queuing in Pseudo[n]polyrotaxanes: A Novel Variant of Supramolecular Motion (pages 2238–2241)

      Philip E. Mason, Dr. Ian W. Parsons and Malcolm S. Tolley

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622381

      Thumbnail image of graphical abstract

      The movement of cyclophane rings along polymer chains may be appropriately described in terms of threading, passage along the thread, and unthreading (see picture). An NMR study of this shows that the molecules need to queue up in order to escape from the complexing polymer chain.

    16. A Triphosphete and a Spirocyclic Cation with a PP4 Skeleton and a 10e Spiro P Atom (pages 2242–2244)

      Prof. Dr. Hans H. Karsch, Dipl.-Chem. Eva Witt and Prof. F. Ekkehardt Hahn

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622421

      Thumbnail image of graphical abstract

      The first triphosphete 1a and its arsenic analog 1b are the products of the reactions of PCl3 and AsCl3, respectively, with Li[C(PPh2)2-(SiMe3)]. The side product Ph2(Cl)P[DOUBLE BOND]C(PPh2)(SiMe3) 2 reacts further with 1a and NaBPh4 by chloride abstraction to yield the spirocyclic ten-electron cation 3 with a pseudo-trigonal-bipyramidal PP4 skeleton.

    17. Donor/Acceptor Complexes in Hydrogen-Bonded Networks: pH-Dependent Self-Organization (pages 2244–2246)

      Prof. Dr. Hans Bock, Dr. Wolfgang Seitz, Dipl.-Chem. Mark Sievert, Dipl.-Chem. Markus Kleine and Dr. Jan W. Bats

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622441

      Thumbnail image of graphical abstract

      Novel aspects for new materials are uncovered in the structures of donor/acceptor complexes in hydrogen-bonded networks. Three examples are presented: the herringbone pattern of mixed-stack donors and acceptors can be planarized, the hydrogen-bonded network can be stretched by included hydrate molecules to accommodate larger π-donors (see below), and the donor/acceptor function can be swapped by proton exchange.

    18. A New Chiral, Cationic β-Amino Alcohol Equivalent: A Variable Approach to Enantiomerically Pure Building Blocks for Hydroxyethylene Isosters (pages 2247–2248)

      Dr. Karsten Danielmeier, Dipl.-Chem. Kerstin Schierle and Prof. Dr. Eberhard Steckhan

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622471

      Thumbnail image of graphical abstract

      Anodic oxidation of (5S)- and (5R)-2 provides (4RS,5S)- and (4RS,5R)-5-chloromethyl-4-methoxyoxazolidin-2-one 3, respectively, in good yields. These are chiral cationic amidoalkylation reagents and, through diastereoselective nucleophilic methoxy group exchange, afford variably functionalized enantiomerically pure amino alcohols 4 as well as 1-substituted 2,3-epoxypropylamines 1, which are precursors for peptidomimetics.

    19. The Nature of the Starter Unit for the Rapamycin Polyketide Synthase (pages 2249–2251)

      Philip A. S. Lowden, Dr. Günter A. Böhm, Dr. James Staunton and Dr. Peter F. Leadlay

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622491

      Thumbnail image of graphical abstract

      A remarkably high level of incorporation is observed when 2,2,5,5-tetradeutero -3,4- dihydroxycyclo -hexanecarboxylic acid is fed to the rapamycin-producing organism. Intriguingly, however, analysis of the gene sequence for the rapamycin polyketide synthase has suggested that the free acid may not normally be involved in rapamycin biosynthesis.

    20. [Rh(7-SPh-8-Me-7,8-C2B9H10)(PPh3)2]: A New Rhodacarborane with Enhanced Activity in the Hydrogenation of 1-Alkenes (pages 2251–2253)

      Dr. Francesc Teixidor, Miquel A. Flores, Dr. Clara Viñas, Dr. Raikko Kivekäs and Dr. Reijo Sillanpää

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622511

      Thumbnail image of graphical abstract

      Hydrogenation of 1-hexene is eight fimes faster with the rhodacarborane complex 1 than with [RhCl(PPh3)3]. The sulfur atom bound to the open face favors the interaction of the rhodium center with the more active B-H vertices situated on this face.

    21. Bimetallic Hydroformylation Catalysis: In Situ Characterization of a Dinuclear Rhodium(II) Dihydrido Complex with the Largest Rh–HNMR Coupling Constant (pages 2253–2256)

      Rhonda C. Matthews, Donna K. Howell, Dr. Wei-Jun Peng, Spencer G. Train, Dr. W. Dale Treleaven and Prof. George G. Stanley

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622531

      Thumbnail image of graphical abstract

      The catalytically active complex in the homogeneously catalyzed, regioselective hydroformylation is possibly the dinuclear complex dication 1. The 1J(Rh,H) coupling constant of 164 Hz is the largest such value ever reported and may be a distinctive marker for dinuclear RhII complexes with terminal hydrido ligands.

    22. Proximate, Synperiplanar Diazene/Diazene Substrates: N[DOUBLE BOND]N/N[DOUBLE BOND]NO and ON[DOUBLE BOND]N/N[DOUBLE BOND]NO Photometathesis Reactions (pages 2256–2259)

      Dipl.-Chem. Kai Exner, Dr. Dirk Hochstrate, Dr. Manfred Keller, Prof. Dr. Frank-Gerrit Klärner and Prof. Dr. Horst Prinzbach

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622561

      Thumbnail image of graphical abstract

      In the bisdiazene 1 and its N-oxides the two synperiplanar chromophores are fixed in so far the “best” stereochemical arrangement for [2π + 2π] photocycloaddition. The formation of metathesis isomers 3 in the case of the oxides is taken as evidence for the intermediacy of the respective tetraazetidine oxides 2.

    23. Stereoselective Synthesis of Steroids with the Heck Reaction (pages 2259–2261)

      Prof. Dr. Lutz F. Tietze, Dipl.-Chem. Thomas Nöbel and Dr. Maurus Spescha

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622591

      Thumbnail image of graphical abstract

      By means of a double Heck reaction the pharmacologically interesting estrapentaene 3 can be synthesized regio- and stereoselectively from (Z)-(2-bromoethenyl)-bromobenzene (1) and the indene derivative 2. A variety of novel steroids can be obtained by variation of the benzene and indene components and subsequent functionalization.

    24. Diastereo- and Enantioselective Synthesis of C2-Symmetric, Protected 1,n-Diamines from Dialdehydes (pages 2261–2263)

      Prof. Dr. Dieter Enders and Dipl.-Chem. Michaela Meiers

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.199622611

      Thumbnail image of graphical abstract

      The nucleophilic 1,2-addition of organocerium compounds to SAMP-hydrazones of dialdehydes 1 is the key step for the stereoselective synthesis of N-propionyl-protected, C2-symmetric diamines 2. Because the nucleophiles and dialdehydes can be varied, this method offers a flexible, highly diastereo- and enantioselective synthetic pathway to this important class of compounds.

  4. Book Reviews

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

SEARCH

SEARCH BY CITATION