Angewandte Chemie International Edition

Cover image for Vol. 43 Issue 9

February 20, 2004

Volume 43, Issue 9

Pages 1033–1167

    1. Cover Picture: Nontoxic Membrane-Active Antimicrobial Arylamide Oligomers (Angew. Chem. Int. Ed. 9/2004) (page 1033)

      Dahui Liu, Sungwook Choi, Bin Chen, Robert J. Doerksen, Dylan J. Clements, Jeffrey D. Winkler, Michael L. Klein and William F. DeGrado

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200490021

      The amphiphilic nature of a highly selective antimicrobial arylamide oligomer is shown by the simulation of its conformation at a water/octane interface. Arginine end groups make this oligomer the most amphiphilic in the series studied and increase its overall hydrophobic moment. While the former property correlates with its low toxicity, the latter correlates with a high antimicrobial activity. More details are described in the Communication by DeGrado and co-workers on page 1158 ff.

    2. Graphical Abstract: Angew. Chem. Int. Ed. 9/2004 (pages 1036–1043)

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200490022

    3. You have free access to this content
    4. You have free access to this content
    5. Asymmetric Cycloisomerization of 1,6- and 1,7-Enynes by Transition-Metal Catalysts (pages 1048–1052)

      Ian J. S. Fairlamb

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200301699

      Thumbnail image of graphical abstract

      Highly functionalized carbo- and heterocycles can be prepared enantioselectively from simple enynes in transition-metal-catalyzed reactions. This versatile, atom-economic, and environmentally friendly approach has become a mainstay in natural product synthesis. The concise synthesis of (+)-pilocarpine is one example (see scheme). binap=2,2′-bis(diphenylphosphanyl)-1,1′-binaphthyl), cod=cyclooctadiene, RT=room temperature.

    6. Hermann Staudinger and the Origin of Macromolecular Chemistry (pages 1054–1063)

      Rolf Mülhaupt

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200330070

      Staudinger's visions paved the way for the development of modern polymeric materials with very versatile properties and new opportunities at the interface of materials and life sciences. This is confirmed in this Essay, written to mark the 50th anniversary of the award of the Nobel Prize for Chemistry to Hermann Staudinger. His revolutionary concept, which initially attracted heavy opposition, marked the beginning of the new era of rational molecular design of structural and functional polymeric materials, whose property profiles are tailored by varying their molecular architectures.

    7. Hermann Staudinger and the Future of Polymer Research Jubilees—Beloved Occasions for Cultural Piety (pages 1064–1076)

      Helmut Ringsdorf

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200330071

      Chemistry was his life, but Hermann Staudinger's dreams belonged to biology and to the unity of chemistry and biology. That is the central theme of this Essay, which, on the occasion of the fiftieth anniversary of the award of the Nobel Prize to Hermann Staudinger, discusses the significance of Staudinger's discoveries for the biosciences, not only retrospectively, but deliberately also prospectively. General questions of science ethics and the interplay of research, politics, and responsibility are also considered.

    8. Nature or Petrochemistry?—Biologically Degradable Materials (pages 1078–1085)

      Stefan Mecking

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200301655

      Thumbnail image of graphical abstract

      Biodegradable plastics based on renewable raw materials are interesting alternatives considering the limited availability of fossil fuel feedstocks and the emission of greenhouse gases. Biological degradability has been defined in Germany since 1998 by an industrial standard, the logo of which is depicted.

    9. Ae[Be2N2]: Nitridoberyllates of the Heavier Alkaline-Earth Metals (pages 1088–1092)

      Mehmet Somer, Alper Yarasik, Lev Akselrud, Stefano Leoni, Helge Rosner, Walter Schnelle and Rüdiger Kniep

      Article first published online: 2 FEB 2004 | DOI: 10.1002/anie.200352796

      Thumbnail image of graphical abstract

      Complex anionic partial structures of the general formula [BeN] occur in nitridoberyllates Ae[Be2N2] (Ae=Mg, Ca, Sr, Ba). Planar 4.82 nets are present in Ca[Be2N2] and Sr[Be2N2] (see structure; Ca, Sr: gray; Be: purple; N: green), whereas Mg[Be2N2] displays puckered 63 nets connected to form double layers and a peculiar bonding situation for nitrogen.

    10. An Easy and Scalable Method for the Partial Alignment of Organic Molecules for Measuring Residual Dipolar Couplings (pages 1092–1094)

      Burkhard Luy, Kyryl Kobzar and Horst Kessler

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352860

      Thumbnail image of graphical abstract

      Stretched polystyrene gel (see picture) induces partial alignment of small molecules in an organic solvent for the measurement of residual dipolar couplings in high-resolution NMR spectroscopy. The degree of orientation can be varied over a wide range by the amount of cross-linking of the polymer. An important NMR parameter can thus be measured routinely.

    11. Decarbonylative Heck Olefination of Enol Esters: Salt-Free and Environmentally Friendly Access to Vinyl Arenes (pages 1095–1098)

      Lukas J. Gooßen and Jens Paetzold

      Article first published online: 29 JAN 2004 | DOI: 10.1002/anie.200352357

      Thumbnail image of graphical abstract

      Thank you, no salt on the side. In this variant of the Heck olefination, enol esters serve as environmentally friendly synthetic equivalents of aryl halides. These reactants, in turn, are available from a waste-free synthesis from carboxylic acids and propyne. Thus, a salt-free overall process has been devised for preparing vinyl arenes from a variety of aromatic carboxylic acids.

    12. Pityriarubins, Biologically Active Bis(indolyl)spirans from Cultures of the Lipophilic Yeast Malassezia furfur (pages 1098–1100)

      Bernhard Irlinger, Hans-Joachim Krämer, Peter Mayser and Wolfgang Steglich

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352549

      Thumbnail image of graphical abstract

      Indole alkaloids, such as pityriarubin A (1), may be of importance for the pathogenesis of the common skin disease pityriasis versicolor. The metabolite 1 is produced in cultures of the lipophilic yeast Malassezia furfur with tryptophan present as the sole source of nitrogen. The structures of the pityriarubins were derived from spectroscopic investigations, and insight into their biosynthesis was gained by feeding experiments with [1′-13C]tryptophan.

    13. New Perspectives for the Design of Molecular Actuators: Thermally Induced Collapse of Single Macromolecules from Cylindrical Brushes to Spheres (pages 1101–1104)

      Chengming Li, Nikhil Gunari, Karl Fischer, Andreas Janshoff and Manfred Schmidt

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352845

      Thumbnail image of graphical abstract

      Polymethacrylates with densely grafted poly-N-isopropylacrylamide side chains change their shape at the lower critical solution temperature from cylindrical brushes (left) to spherical structures (right). This is an interesting example of a temperature-induced cylinder-to-sphere transition observed for single macromolecules.

    14. Carbohydrate Scaffolds for Combinatorial Syntheses That Allow Selective Deprotection of All Four Positions Independent of the Sequence (pages 1104–1107)

      Udo Hünger, Janina Ohnsmann and Horst Kunz

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352919

      Thumbnail image of graphical abstract

      Irrespective of the sequence, the carbohydrate scaffold 1 as a molecular platform for combinatorial diversification can be selectively deprotected and equipped with side chains, for example amino acids or peptides, in every position (see picture). This allows the flexible arrangement of functional groups and structural elements. PG=protective group.

    15. Direct Catalytic Enantioselective α-Aminoxylation of Ketones: A Stereoselective Synthesis of α-Hydroxy and α,α′-Dihydroxy Ketones (pages 1109–1112)

      Anders Bøgevig, Henrik Sundén and Armando Córdova

      Article first published online: 9 FEB 2004 | DOI: 10.1002/anie.200353018

      Thumbnail image of graphical abstract

      Proline-catalyzed reactions between unmodified ketones and nitrosobenzene proceed with excellent diastereo- and enantioselectivities to provide protected α-hydroxy and α,α′-dihydroxy ketones [Eq. (1)]. Such compounds with chiral α-hydroxy carbonyl units are crucial in natural product synthesis.

    16. Direct Proline-Catalyzed Asymmetric α-Aminoxylation of Ketones (pages 1112–1115)

      Yujiro Hayashi, Junichiro Yamaguchi, Tatsunobu Sumiya and Mitsuru Shoji

      Article first published online: 11 FEB 2004 | DOI: 10.1002/anie.200353085

      Thumbnail image of graphical abstract

      Nitrosobenzene is the oxygen source in the direct catalytic enantioselective α-aminoxylation of ketones catalyzed by L-proline [Eq. (1)]. Versatile α-aminoxylated ketones are obtained in high yield and with excellent enantioselectivities.

    17. Size-Dependent Magnetic Properties of Colloidal Mn3O4 and MnO Nanoparticles (pages 1115–1117)

      Won Seok Seo, Hyong Hoon Jo, Kwangyeol Lee, Bongsoo Kim, Sang Jun Oh and Joon T. Park

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352400

      Thumbnail image of graphical abstract

      Highly crystalline and monodisperse MnO and Mn3O4 nanoparticles are prepared by thermal decomposition of [Mn(acac)2] in oleylamine under an inert atmosphere in the presence and absence of a small amount of water, respectively (see picture). The particle size of both manganese oxide systems can be easily manipulated by changing the employed reaction temperature, and it has been demonstrated that the magnetic behavior depends on the size of the particles.

    18. Dioxazocinium Ortho Esters: A Class of Highly pH-Vulnerable Amphiphiles (pages 1117–1120)

      Kolbot By and Michael H. Nantz

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352589

      Thumbnail image of graphical abstract

      Making and breaking lipids: A general synthesis of a new class of ortho ester lipids from a dioxazocinium ketene acetal is disclosed. Both single- and dual-chain analogues were prepared, and the most sensitive of these (see structure) was shown to disassemble at 38 °C within 6 h at pH 5.0.

    19. A New Route to Lactam Precursors from Cycloalkanes: Direct Production of Nitrosocycloalkanes or Cycloalkanone Oximes by Using tert-Butyl Nitrite and N-Hydroxyphthalimide (pages 1120–1123)

      Tomotaka Hirabayashi, Satoshi Sakaguchi and Yasutaka Ishii

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352741

      Thumbnail image of graphical abstract

      Clean and selective: Nitrosation and oximation of cycloalkanes was achieved by treating them with tBuONO under Ar in the presence of a catalytic amount of N-hydroxyphthalimide (see scheme). The novel, clean nitrosation procedure uses halogen-free, relatively mild reaction conditions and results in good product selectivity (almost no organic byproducts) and high recovery of the catalyst.

    20. An Isolable Radical Anion and Dianion of a Cyclotetrasilane: Synthesis and Structure of [Si{1,2-(NEt)2C6H4}]4. and [Si{1,2-(NEt)2C6H4}]42− (pages 1124–1126)

      Barbara Gehrhus, Peter B. Hitchcock and Lihong Zhang

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352882

      Thumbnail image of graphical abstract

      Silicon squares up: The silylene Si[1,2-(NR)2C6H4] (R=CH2tBu) is thermally stable owing to its bulky substituent. What effect will a reduction of the size of R have on the stability of a two-coordinate SiII species? Results show that a silylene with R=Et cannot be isolated but will yield a stable radical anion (see picture) and dianion of a cyclotetrasilane.

    21. Oxonitriles: Multicomponent Grignard Addition–Alkylations (pages 1126–1129)

      Fraser F. Fleming, Zhiyu Zhang, Qunzhao Wang and Omar W. Steward

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352920

      Thumbnail image of graphical abstract

      Three at a time: Sequential carbonyl addition, chelation-controlled conjugate addition, and alkylation triggers the multicomponent assembly of diverse nitriles. The chelation-controlled conjugate addition–alkylation installs three new stereocenters (see scheme), thereby generating substituted nitriles that are ideal terpenoid precursors as illustrated in the synthesis of epi-dehydroabietic acid.

    22. Porphyrin Traps Its Terminator! Concerted and Stepwise Porphyrin Degradation Mechanisms Induced by Heme-Oxygenase and Cytochrome P450 (pages 1129–1132)

      Pankaz K. Sharma, Rouslan Kevorkiants, Sam P. de Visser, Devesh Kumar and Sason Shaik

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352943

      Thumbnail image of graphical abstract

      Concerted or stepwise? A homolytic stepwise pathway is taken by the enzyme heme-oxygenase (HO) to degrade the porphyrin ring in heme species. The porphyrin ring assists the enzyme by trapping the hydroxyl radical during the degradation (see scheme). HO is compared to cytochrome P450.

    23. Stille Coupling Made Easier—The Synergic Effect of Copper(I) Salts and the Fluoride Ion (pages 1132–1136)

      Simon P. H. Mee, Victor Lee and Jack E. Baldwin

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352979

      Thumbnail image of graphical abstract

      CsF and CuI do the trick: Stille coupling reactions of aryl/vinyl iodides, triflates, and bromides with aryl/vinyl stannanes are greatly enhanced by the inclusion of CsF and CuI in the reaction mixture (see scheme; Conditions A: [Pd(PPh3)4]/CsF/CuI/DMF/45 °C; Conditions B: PdCl2/PtBu3/CsF/CuI/DMF/45 °C).

    24. Energy-Barrier Enhancement by Ligand Substitution in Tetrairon(III) Single-Molecule Magnets (pages 1136–1139)

      Andrea Cornia, Antonio C. Fabretti, Pierfrancesco Garrisi, Cecilia Mortalò, Daniele Bonacchi, Dante Gatteschi, Roberta Sessoli, Lorenzo Sorace, Wolfgang Wernsdorfer and Anne-Laure Barra

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352989

      Thumbnail image of graphical abstract

      A relaxing time: A dramatic increase of the energy barrier (Ueff) in tetrairon(III) single-molecule magnets can be achieved by simple chemical modification. Site-specific replacement of the six methoxide bridges in [Fe4(OMe)6(dpm)6] (Hdpm=dipivaloylmethane; Ueff/kB=3.5 K) with two tripodal 1,1,1-tris(hydroxymethyl)ethane (H3thme) ligands affords the compound [Fe4(thme)2(dpm)6] (see figure) with Ueff/kB=15.6(2) K and a magnetic relaxation time exceeding 1000 s below 0.2 K.

    25. You have free access to this content
      Gold-Nanotube Membranes for the Oxidation of CO at Gas–Water Interfaces (pages 1140–1142)

      Marco A. Sanchez-Castillo, Claudia Couto, Won Bae Kim and James A. Dumesic

      Article first published online: 3 FEB 2004 | DOI: 10.1002/anie.200353238

      Thumbnail image of graphical abstract

      Membranes of gold nanotubes in polycarbonate films are used to study catalytic reactions at gas–liquid interfaces. The catalytic properties of gold for CO oxidation with O2 can be enhanced by liquid water and promoted by increasing the pH value of the solution. The membrane is sandwiched between other membranes that contain thiol-functionalized gold nanotubes, which control mass transport to the central reaction zone (see picture).

    26. Templated Ligand Assembly by Using G-Quadruplex DNA and Dynamic Covalent Chemistry (pages 1143–1146)

      Andrew M. Whitney, Sylvain Ladame and Shankar Balasubramanian

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200353069

      Thumbnail image of graphical abstract

      Reversible disulfide chemistry is used to identify ligands that bind G-quadruplex DNA from a small dynamic combinatorial library (DCL) (see scheme). The biological macromolecular target is shown to induce an equilibrium shift. Surface plasmon resonance demonstrates that the two amplified species bind the quadruplex DNA.

    27. Self-Assembly of Large-Scale Micropatterns on Aligned Carbon Nanotube Films (pages 1146–1149)

      Huan Liu, Shuhong Li, Jin Zhai, Huanjun Li, Quanshui Zheng, Lei Jiang and Daoben Zhu

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200351988

      Thumbnail image of graphical abstract

      Long-range forces (capillary force) are used in the self-assembly of three-dimensional (3D) micropatterns of aligned carbon nanotubes films. This method involves the spreading of a droplet of water after the growth of the carbon nanotube film. Controlling the density of the carbon nanotube film is crucial to the formation of 3D patterned structures (see picture).

    28. Polymorphism of 1,3,5-Trinitrobenzene Induced by a Trisindane Additive (pages 1149–1155)

      Praveen K. Thallapally, Ram K. R. Jetti, Amy K. Katz, H. L. Carrell, Kuldeep Singh, Kakali Lahiri, Sambasivarao Kotha, Roland Boese and Gautam R. Desiraju

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352253

      Thumbnail image of graphical abstract

      The most stable is not necessarily the most easy to obtain! Two new stable crystal forms of the 120 year old compound sym-trinitrobenzene are reported. These elusive forms have been obtained by the use of an additive, trisindane, that can act as a mimic in the crystallization experiment (see scheme).

    29. Two-Dimensional IR Pressure-Jump Spectroscopy of Adsorbed Species for Zeolites (pages 1155–1158)

      Stéphane Chenevarin and Frédéric Thibault-Starzyk

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200352754

      Thumbnail image of graphical abstract

      Probing pores: Adsorbed species on a zeolite are perturbed by pressure jumps (see picture; top), relaxation by means of diffusion and adsorption follows and is monitored by fast IR (middle). 2D maps are obtained by a second Fourier transform (bottom): the spectrum of each adsorbate/site pair is distinguished.

    30. Nontoxic Membrane-Active Antimicrobial Arylamide Oligomers (pages 1158–1162)

      Dahui Liu, Sungwook Choi, Bin Chen, Robert J. Doerksen, Dylan J. Clements, Jeffrey D. Winkler, Michael L. Klein and William F. DeGrado

      Article first published online: 27 JAN 2004 | DOI: 10.1002/anie.200352791

      Thumbnail image of graphical abstract

      Cracking the case: Aryl amide oligomers with amphiphilic secondary structure were designed that attack bacteria by lysing their membranes. A variety of groups were appended to the lead compound to adjust its overall charge, hydrophobicity, and hydrophobic moment. An Arg-containing oligomer (see figure) was found to have good antimicrobial activity and low toxicity towards human erythrocytes.

    31. You have free access to this content
      Preview: Angew. Chem. Int. Ed. 9/2004 (page 1167)

      Article first published online: 18 FEB 2004 | DOI: 10.1002/anie.200490024

SEARCH

SEARCH BY CITATION