Chemistry - A European Journal

Cover image for Vol. 18 Issue 46

November 12, 2012

Volume 18, Issue 46

Pages 14541–14874

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
    1. You have free access to this content
      Cover Picture: n-Doping of Organic Electronic Materials Using Air-Stable Organometallics: A Mechanistic Study of Reduction by Dimeric Sandwich Compounds (Chem. Eur. J. 46/2012) (page 14541)

      Dr. Song Guo, Dr. Swagat K. Mohapatra, Alexander Romanov, Prof. Tatiana V. Timofeeva, Prof. Kenneth I. Hardcastle, Dr. Kada Yesudas, Dr. Chad Risko, Prof. Jean-Luc Brédas, Prof. Seth R. Marder and Dr. Stephen Barlow

      Article first published online: 7 NOV 2012 | DOI: 10.1002/chem.201290198

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      The dimers of rhodocenes and mixed cyclopentadienyl/arene Group 8 species are air-stable, but may be used to n-dope materials with electron affinities as low as 2.8 eV. Monitoring these reactions in solution by UV/Vis spectroscopy indicates that two different mechanisms are possible, depending on the dimer in question, the acceptor, and the experimental conditions. In the case of [{RuCp*(C6H3Et3)}2] and 6,13-bis[tri(isopropyl)silylethynyl]pentacene (shown) the reaction proceeds by rate-determining electron transfer from dimer to acceptor, followed by cleavage of the dimer cation. For more details see the Full Paper by S. R. Marder, S. Barlow et al. on page 14760 ff.

  2. Graphical Abstract

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
    1. Graphical Abstract: Chem. Eur. J. 46/2012 (pages 14544–14553)

      Article first published online: 7 NOV 2012 | DOI: 10.1002/chem.201290199

  3. News

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
  4. Review

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
    1. Liquid Crystals

      Advances in Metal-Free Heterocycle-Based Columnar Liquid Crystals (pages 14560–14588)

      Dr. Brindaban Roy, Nirupam De and Prof. Krishna C. Majumdar

      Article first published online: 18 OCT 2012 | DOI: 10.1002/chem.201200483

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      Discipline in fluids! Recent approaches involving the synthesis of columnar liquid crystals based on heterocyclic moieties are highlighted (see figure). This Review is intended to realize the important structural features; mesomorphic, electronic, and optical properties; and superiority of applications of these materials.

  5. Communications

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
    1. Redox Chemistry

      Ligand-Centered Redox Activity in Cobalt(II) and Nickel(II) Bis(phenolate)–Dipyrrin Complexes (pages 14590–14593)

      Amélie Kochem, Linus Chiang, Dr. Benoit Baptiste, Dr. Christian Philouze, Dr. Nicolas Leconte, Dr. Olivier Jarjayes, Prof. Tim Storr and Prof. Fabrice Thomas

      Article first published online: 5 OCT 2012 | DOI: 10.1002/chem.201202882

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      One for all: A trianionic ligand containing the biologically relevant moieties phenolate and porphyrin was designed and synthesized. One-electron oxidation of the nickel and cobalt complexes of these ligands affords an unprecedented and highly stable hybrid porphyrinyl–phenoxyl radical bound to the metal center. Two-electron oxidation of these complexes leads to the M2+–(close-shell two-electron oxidized ligand) species.

    2. N-Heterocyclic Carbene Complexes

      Synthesis of Complexes Containing an Anionic NHC Ligand with an Unsubstituted Ring-Nitrogen Atom (pages 14594–14598)

      Dr. Tim Kösterke, Jutta Kösters, Prof. Dr. Ernst-Ulrich Würthwein, Dr. Christian Mück-Lichtenfeld, Christian Schulte to Brinke, Prof. Dr. Fernando Lahoz and Prof. Dr. F. Ekkehardt Hahn

      Article first published online: 12 OCT 2012 | DOI: 10.1002/chem.201202973

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      Oxidative addition: Complexes containing an anionic NHC ligand with an unsubstituted nitrogen atom within the heterocycle have been prepared by oxidative addition of 2-chloro-N-methylbenzimidazole to Ni0 and Pt0 (see scheme). The “naked” nitrogen atom of the NHC ligand reacts as a strong nucleophile.

    3. Luminescence

      Aggregation-Induced Photoluminescent Changes of Naphthyridine–BF2 Complexes (pages 14599–14604)

      Li Quan, Dr. Yong Chen, Dr. Xiao-Jun Lv and Prof. Dr. Wen-Fu Fu

      Article first published online: 2 OCT 2012 | DOI: 10.1002/chem.201201592

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      Luminous boron: New 1,8-naphthyridine–BF2 complexes with strong emissions both in solution and in the solid state have been developed (see figure). Aggregation-induced blueshifts of emissions in DMSO/water mixtures and solvent-influenced luminescence in crystalline states have been observed and are discussed.

    4. Nanostructures

      Self-Generated Etchant for Synthetic Sculpturing of Cu2O-Au, Cu2O@Au, Au/Cu2O, and 3D-Au Nanostructures (pages 14605–14609)

      Dr. Maolin Pang, Qingxiao Wang and Prof. Dr. Hua Chun Zeng

      Article first published online: 9 OCT 2012 | DOI: 10.1002/chem.201202765

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      Structures of Gold: A simple transformative method for nanoscale sculpturing has been developed. Five different types of complex nanocomposites of cuprite and gold have been formed by using this self-etching approach (see figure).

    5. Self-Assembly

      Controlling the Dimensionality and Structure of Supramolecular Porphyrin Assemblies by their Functional Substituents: Dimers, Chains, and Close-Packed 2D Assemblies (pages 14610–14613)

      Dr. Cristian Iacovita, Dr. Petra Fesser, Saranyan Vijayaraghavan, Mihaela Enache, Prof. Dr. Meike Stöhr, Prof. Dr. François Diederich and Prof. Dr. Thomas A. Jung

      Article first published online: 12 OCT 2012 | DOI: 10.1002/chem.201201037

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      Repulsive interactions: A staging of supramolecular aggregation from (0D) clusters to (1D) chains and (2D) assemblies as a function of molecular coverage of dipolar porphyrins adsorbed on the Ag(111) surface is described. It displays a complex interplay of both attractive and repulsive molecule–molecule interactions, the emergence of chirality, and the registry of the substrate (see figure).

    6. 2D-Oriented Self-Assembly of Peptides Induced by Hydrated Electrons (pages 14614–14617)

      Dr. Yun-xiang Pan, Prof. Chang-jun Liu, Dr. Shuai Zhang, Yue Yu and Prof. Mingdong Dong

      Article first published online: 20 SEP 2012 | DOI: 10.1002/chem.201200745

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      Peptide assembly: A 2D peptide (Aβ16-22) film was produced successfully by introducing hydrated electrons into the assembly process of Aβ16-22 (see figure). The interplay between experiment and theoretical calculation indicates that the film formation can be enhanced through the interactions between hydrated electrons and Aβ16-22.

    7. Synthetic Methods

      Protonation-Triggered Generation of Acylcobalt Species from Alkyne–[Co2(CO)6] Complexes and Their Reaction with Alkenes (pages 14618–14621)

      Isao Ooi, Takafumi Sakurai, Dr. Jun Takaya and Prof. Dr. Nobuharu Iwasawa

      Article first published online: 10 OCT 2012 | DOI: 10.1002/chem.201202749

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      An efficient protocol for the generation of acylcobalt species from alkyne–[Co2(CO)6] complexes is realized by treatment of the complexes with AcOH and pyridine. The generated acylcobalt species smoothly underwent addition reactions with various alkenes to give alkyl alkenyl ketones in good yield (see scheme).

    8. Photocatalysis

      Rapid Anodic Formation of High Aspect Ratio WO3 Layers with Self-Ordered Nanochannel Geometry and Use in Photocatalysis (pages 14622–14626)

      Dr. Wei Wei, Santosh Shaw, Kiyoung Lee and Prof. Dr. Patrik Schmuki

      Article first published online: 5 OCT 2012 | DOI: 10.1002/chem.201202420

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      Channel hopping: The formation of WO3 layers with an aligned nanochannel morphology by using self-organizing anodization of a tungsten metal substrate is demonstrated. The nanochannel layers with diameters of approximately 9 nm can be grown to about 10 μm thickness. Layers optimized for length and structure are promising for visible-light photocatalytic applications, such as water-splitting photoanodes (see figure).

    9. Carbenes

      Anionic 1,2,3-Triazole-4,5-diylidene: A 1,2-Dihapto Ligand for the Construction of Bimetallic Complexes (pages 14627–14631)

      Xiaoyu Yan, Dr. Jean Bouffard, Dr. Gregorio Guisado-Barrios, Dr. Bruno Donnadieu and Prof. Guy Bertrand

      Article first published online: 5 OCT 2012 | DOI: 10.1002/chem.201202862

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      A super pyrazolate: Deprotonation of the flanking hydrogen of metal complexes of mesoionic carbenes (MICs) offers a simple and general route for the preparation of bimetallic complexes of a 1,2-dihapto anionic dicarbene ligand that is isoelectronic with widely used pyrazolate ligands, while conferring greater electron donation and stronger M[BOND]L bonds (see scheme).

    10. Single-Molecule Magnets

      Modulation of Homochiral DyIII Complexes: Single-Molecule Magnets with Ferroelectric Properties (pages 14632–14637)

      Prof. Dr. Xi-Li Li, Chun-Lai Chen, Yu-Liang Gao, Prof. Dr. Cai-Ming Liu, Xiang-Li Feng, Prof. Dr. Yang-Hai Gui and Prof. Dr. Shao-Ming Fang

      Article first published online: 12 OCT 2012 | DOI: 10.1002/chem.201201190

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      Homochiral DyIII complexes: By changing the ligand-to-metal ratio, enantiomeric pairs of a DyIII complex of different nuclearity could be obtained. The mono- and dinuclear complexes exhibit characteristics of single-molecule magnets and different slow magnetic relaxation processes. In addition, the dinuclear complexes (see picture) exhibit ferroelectric behavior, thus representing the first chiral polynuclear lanthanide-based single-molecule magnets with ferroelectric properties.

    11. Amination

      NIS-Catalyzed Reactions: Amidation of Acetophenones and Oxidative Amination of Propiophenones (pages 14638–14642)

      Manjunath Lamani and Dr. Kandikere Ramaiah Prabhu

      Article first published online: 5 OCT 2012 | DOI: 10.1002/chem.201202703

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      Single-step amination: The N-iodosuccinimide (NIS)-catalyzed amidation of acetophenone derivatives by using tert-butylhydroperoxide (TBHP) as an oxidant is presented. A variety of acetyl derivatives of heterocyclic compounds were easily converted to their corresponding ketoamides under these conditions. A new, NIS-catalyzed amination of propiophenone and its derivatives in the presence of TBHP to furnish the corresponding 2-aminoketone derivatives is the first reported single-step amination of propiophenone derivatives.

    12. Allylation

      Copper- and Phosphine-Ligand-Free Palladium-Catalyzed Direct Allylation of Electron-Deficient Polyfluoroarenes with Allylic Chlorides (pages 14643–14648)

      Yan-Bo Yu, Shilu Fan and Prof. Dr. Xingang Zhang

      Article first published online: 10 OCT 2012 | DOI: 10.1002/chem.201202824

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      Simply id(all)ylic: A copper- and phosphine-ligand-free Pd-catalyzed direct allylation of electron-deficient polyfluoroarenes with allylic chlorides and the reaction mechanism are described (see scheme). The simple catalytic system, broad substrate scope, and excellent functional-group compatibility of this protocol provides a useful and facile access to allylated polyfluoroarenes.

  6. Full Papers

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
    1. Hydrogels

      Supramolecular Polymer Hydrogels from Bolaamphiphilic L-Histidine and Benzene Dicarboxylic Acids: Thixotropy and Significant Enhancement of EuIII Fluorescence (pages 14650–14659)

      Yaqing Liu, Dr. Tianyu Wang and Prof. Dr. Minghua Liu

      Article first published online: 23 OCT 2012 | DOI: 10.1002/chem.201202637

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      Gelling together: The combination of the supramolecular polymers bolaamphiphilic L-histidine and benzene dicarboxylic acid was found to form hydrogels (see scheme), even though the components are unable to form gels independently. Depending on the structures of the dicarboxylic acids, the hydrogels show thixotropic properties or strongly enhanced luminescence upon doping with EuIII.

    2. Radical Cations

      The Remarkable Effect of the Manganese Ion with Dioxygen on the Stability of π-Conjugated Radical Cations (pages 14660–14670)

      Dr. Ali El-Agamey and Prof. Shunichi Fukuzumi

      Article first published online: 25 SEP 2012 | DOI: 10.1002/chem.201201328

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      Life changes: Mn ions show a substantial effect on the lifetime of π-conjugated radical cations (D.+) in the presence of oxygen (see scheme). However, this remarkable effect is greatly diminished if either oxygen or manganese ions are removed from the solution. These observations can be attributed to the inhibition of the back electron transfer between O2. and D.+.

    3. Click Chemistry

      Synthesis and Biological Evaluation of a Library of Glycoporphyrin Compounds (pages 14671–14679)

      Robin Daly, Gisela Vaz, Dr. Anthony M. Davies, Prof. Dr. Mathias O. Senge and Prof. Dr. Eoin M. Scanlan

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201202064

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      All sweetness and light: A library of mono-, di- and trisubstituted glycoconjugated porphyrin compounds was prepared (see figure). A number of biologically active synthetic carbohydrates were conjugated to the porphyrin core. Cellular uptake, photoactivity and subcellular localisation have been examined in the human oesophageal cell carcinoma cell line OE21.

    4. Propagation of Chirality

      Molecular Description of the Propagation of Chirality from Molecules to Complex Systems: Different Mechanisms Controlled by Hydrophobic Interactions (pages 14680–14688)

      Dr. Fabrizio Marinelli, Dr. Alessandro Sorrenti, Valentina Corvaglia, Dr. Vanessa Leone and Dr. Giovanna Mancini

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201202342

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      The long and the short of it: The interactions that drive the transfer of chirality from chiral surfactant molecules to dye/surfactant assemblies were investigated by experiment and theory. Surfactants with a small hydrophobic moiety localize in between dye molecules, thereby stabilizing one enantiomer of a dye conformer. In contrast, surfactants with a large hydrophobic moiety assemble around the helix formed by dye molecules, thus preferentially stabilizing one particular helical handedness.

    5. Sensors

      Nucleic Acid Driven DNA Machineries Synthesizing Mg2+-Dependent DNAzymes: An Interplay between DNA Sensing and Logic-Gate Operations (pages 14689–14694)

      Ron Orbach, Lena Mostinski, Dr. Fuan Wang and Prof. Itamar Willner

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201201995

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      Open the gate! Nucleic acid analytes (inputs) trigger polymerization/nicking DNA machines that synthesize the Mg2+-dependent DNAzymes. The systems allow the amplified detection of the analytes and the activation of the OR, AND, and controlled-AND logic gates by using fluorescence as output signal (see scheme).

    6. Block Copolymers

      Coassembly of Metal and Titanium Dioxide Nanocrystals Directed by Monolayered Block Copolymer Inverse Micelles for Enhanced Photocatalytic Performance (pages 14695–14701)

      Dr. Himadri Acharya, Dr. Jinwoo Sung, Insung Bae, Dr. TaeHee Kim, Dong Ha Kim and Prof. Dr. Cheolmin Park

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201200934

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      Of micelles and metals: Coassembly of anisotropic TiO2 nanocrystals and Ag nanoparticles was achieved in the corona and core regions of monolayered block copolymer micelles, respectively (see figure). Thermal heating removed the block copolymer and the resulting TiO2 network nanostructure with Ag nanoparticles decorating its pores exhibited excellent photocatalytic performance.

    7. Polyacetylenes

      First Perphenylated carbo-Oligoacetylenes: An Extension of the Polytriacetylene Family (pages 14702–14707)

      Dr. Arnaud Rives, Dr. Valérie Maraval, Dr. Nathalie Saffon-Merceron and Prof. Remi Chauvin

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201201555

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      Colorful chain carbo-mers of polyacetylenes are isomers of the well-known polytriacetylenes (PTAs). The three first representatives are shown to exhibit continuously but markedly varying chromophoric properties (see figure).

    8. Graphene

      Covalent Modification of Reduced Graphene Oxide by Means of Diazonium Chemistry and Use as a Drug-Delivery System (pages 14708–14716)

      Guangcheng Wei, Miaomiao Yan, Renhao Dong, Dong Wang, Xiangzhu Zhou, Jingfei Chen and Prof. Dr. Jingcheng Hao

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201200843

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      New horizons: A novel method for covalent modification of reduced graphene oxide (rGO) by means of diazonium chemistry was developed. The functionalized-rGO drug-delivery system was tested for the first time (see scheme) and provided a new vision for functionalizing rGO and studying drug-delivery systems based on graphene materials.

    9. Metathesis

      Linker-Free, Silica-Bound Olefin-Metathesis Catalysts: Applications in Heterogeneous Catalysis (pages 14717–14724)

      Dr. José Cabrera, Dr. Robin Padilla, Dr. Miriam Bru, Dr. Ronald Lindner, Dr. Takeharu Kageyama, Dr. Kristina Wilckens, Dr. Shawna L. Balof, Dr. Hans-Jörg Schanz, Dr. Richard Dehn, Dr. J. Henrique Teles, Dr. Stephan Deuerlein, Dr. Kevin Müller, Dr. Frank Rominger and Dr. Michael Limbach

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201202248

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      Born free: Silica adsorption of ruthenium carbenes with the H2ITap ligand (see figure) yielded heterogeneous materials without the need for tethering groups on the complex or the support. These materials were tested as catalysts in the ring-opening–ring-closing-metathesis of cyclooctene and the cross-metathesis of methyl oleate under continuous-flow conditions. The best complexes showed a TON>4000, which surpasses the most active silica-based materials.

    10. Chiral Hydrogels

      Self-Assembly Studies of a Chiral Bisurea-Based Superhydrogelator (pages 14725–14731)

      Dr. Francisco Rodríguez-Llansola, Dr. Daniel Hermida-Merino, Belén Nieto-Ortega, Dr. Francisco J. Ramírez, Prof. Juan T. López Navarrete, Prof. Juan Casado, Prof. Ian W. Hamley, Dr. Beatriu Escuder, Dr. Wayne Hayes and Dr. Juan F. Miravet

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201200707

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      Supergelator with a twist: A chiral bisurea-based compound is capable of forming supramolecular hydrogels at concentrations as low as 0.2 mM (see figure). Molecular chirality is manifested on the supramolecular level and the soft material is easy to handle.

    11. Gold Complexes

      Coordination Chemistry of Gold Catalysts in Solution: A Detailed NMR Study (pages 14732–14744)

      Dipl.-Chem. Alexander Zhdanko, Dr. Markus Ströbele and Prof. Dr. Martin E. Maier

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201201215

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      Diving in a gold solution: A detailed exploration of the coordination chemistry of eight gold catalysts by NMR spectroscopy in solution was conducted. This covered ligand-exchange reactions, formation and transformation of different oxonium salts, and complexes with sulfide.

    12. Chemosensors

      Femtogram Detection of Explosive Nitroaromatics: Fluoranthene-Based Fluorescent Chemosensors (pages 14745–14751)

      Dr. N. Venkatramaiah, Shiv Kumar and Prof. Satish Patil

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201201764

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      Explosive discoveries: A novel fluoranthene-based fluorescent fluorophore 7,10-bis(4-bromophenyl)-8,9-bis[4-(hexyloxy)phenyl]fluoranthene (S3) and its remarkable properties in applications of explosive detection is reported (see figure). It is anticipated that sensor S3 could be a promising material in the construction of portable optical devices for onsite detection of explosive nitroaromatics.

    13. Stacking Interactions

      Monomer–Dimer Equilibrium for the 5′–5′ Stacking of Propeller-Type Parallel-Stranded G-Quadruplexes: NMR Structural Study (pages 14752–14759)

      Ngoc Quang Do and Prof. Dr. Anh Tuân Phan

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201103295

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      A balancing act: The equilibrium between monomeric and stacked dimeric G-quadruplexes depends on a number of parameters, including the DNA flanking sequence, the DNA concentration, the amount and type of cations, and the temperature.

    14. Sandwich Complexes

      n-Doping of Organic Electronic Materials Using Air-Stable Organometallics: A Mechanistic Study of Reduction by Dimeric Sandwich Compounds (pages 14760–14772)

      Dr. Song Guo, Dr. Swagat K. Mohapatra, Alexander Romanov, Prof. Tatiana V. Timofeeva, Prof. Kenneth I. Hardcastle, Dr. Kada Yesudas, Dr. Chad Risko, Prof. Jean-Luc Brédas, Prof. Seth R. Marder and Dr. Stephen Barlow

      Article first published online: 25 OCT 2012 | DOI: 10.1002/chem.201202591

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      Doped up: Air-stable dimers of pentamethylrhodocene and pentamethylcyclopentadienyl arene ruthenium and iron can be used to n-dope acceptors such as bis[tri(isopropyl)silylethynyl] pentacene. NMR crossover experiments and variable-temperature Vis/NIR kinetic measurements indicate that, depending on the reaction conditions and the choice of dimer and acceptor, this doping can take place by two different mechanisms (see scheme).

    15. Receptors

      An Artificial Estrogen Receptor through Combinatorial Imprinting (pages 14773–14783)

      Dr. Eric Schillinger, Prof. Monika Möder, Dr. Gustaf D. Olsson, Prof. Ian A. Nicholls and Priv.-Doz. Dr. Börje Sellergren

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201201428

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      Receptor mimics: Combinatorially optimized imprinted polymers (MIPs, see figure) targeting endocrine disruptors exhibited a retentivity for estrogen active compounds (EACs), correlating with their inhibitory effect on the natural receptor. By using the optimized MIPs in a model system for water purification, they were capable of near-complete removal of ppb levels of a small group of EACs from water.

    16. Asymmetric Synthesis

      Highly Enantioselective Synthesis of 1,2,3-Substituted Cyclopropanes by Using α-Iodo- and α-Chloromethylzinc Carbenoids (pages 14784–14791)

      Louis-Philippe B. Beaulieu, Dr. Lucie E. Zimmer, Prof. Alexandre Gagnon and Prof. André B. Charette

      Article first published online: 25 SEP 2012 | DOI: 10.1002/chem.201202528

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      Propping up the enantioselectivity: The enantio- and diastereoselective formation of trans-iodo- and trans-chlorocyclopropanes from α-iodo- and α-chlorozinc carbenoids by using a dioxaborolane-derived chiral ligand is reported. The iodocyclopropanes were derivatized into a variety of 1,2,3-substituted cyclopropanes and new insights into the relative electrophilicity of α-haloiodomethylzinc carbenoids are presented (see scheme).

    17. Asymmetric Catalysis

      Bispalladacycle-Catalyzed Michael Addition of In Situ Formed Azlactones to Enones (pages 14792–14804)

      Dipl.-Chem. Manuel Weber, Dr. Sascha Jautze, Dr. Wolfgang Frey and Prof. Dr. René Peters

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201202455

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      Flourishing step economy: The evolution of the catalytic asymmetric addition of azlactones to enones is described. The first-generation approach started from isolated azlactones. In the second-generation approach azlactones could be generated in situ from racemic N-benzoylated amino acids. The third evolution stage could directly use racemic unprotected α-amino acids to form a large number of highly enantioenriched quaternary amino acids derivatives (see figure).

    18. Rhenium Complexes

      Synthesis and Characterization of Terminal [Re(XCO)(CO)2(triphos)] (X=N, P): Isocyanate versus Phosphaethynolate Complexes (pages 14805–14811)

      Dr. Simone Alidori, Dominikus Heift, Dr. Gustavo Santiso-Quinones, Dr. Zoltán Benkő, Prof. Dr. Hansjörg Grützmacher, Dr. Maria Caporali, Dr. Luca Gonsalvi, Dr. Andrea Rossin and Dr. Maurizio Peruzzini

      Article first published online: 28 SEP 2012 | DOI: 10.1002/chem.201202590

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      The first phosphaethynolate complex [Re(PCO)(CO)2(triphos)] and the analogous isocyanate complex have been synthesized and characterized. While the isocyanato complex is linear, the phosphaethynolate complex is strongly bent around the pnictogen center (see scheme).

    19. Multicomponent Reactions

      Amidation of Aldehydes and Alcohols through α-Iminonitriles and a Sequential Oxidative Three-Component Strecker Reaction/Thio-Michael Addition/Alumina-Promoted Hydrolysis Process to Access β-Mercaptoamides from Aldehydes, Amines, and Thiols (pages 14812–14819)

      Jean-Baptiste Gualtierotti, Xavier Schumacher, Dr. Patrice Fontaine, Dr. Géraldine Masson, Dr. Qian Wang and Prof. Dr. Jieping Zhu

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201202291

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      First direct: The direct amidation reactions of aldehydes and alcohols were performed in combination with the oxidative three-component synthesis of α-iminonitriles. In addition, β-mercaptoamides were readily accessed from α,β-unsaturated aldehydes, amines, and thiols by a sequential process that involved a three-component Strecker reaction, Yb(OTf)3-catalyzed thio-Michael addition, and hydrolysis of the resulting β-mercapto-α-iminonitriles (see scheme).

    20. Metallocenes

      Synthesis and Insertion Chemistry of Mixed Tether Uranium Metallocene Complexes (pages 14820–14827)

      Nathan A. Siladke, Jennifer LeDuc, Dr. Joseph W. Ziller and Prof. Dr. William J. Evans

      Article first published online: 9 OCT 2012 | DOI: 10.1002/chem.201201908

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      Adding CO to the mix! A general method for making mixed tethered ligand uranium complexes generated from the bis(tethered alkyl) metallocene [(η5-C5Me4SiMe2CH2C)2U] has been developed. The use of bulky substrates that only react with one of the U[BOND]C bonds yields complexes containing both new tethered ligands and (η5-C5Me4SiMe2CH2C)2− (see scheme). Subsequent reactivity of these mixed complexes with CO is described.

    21. Cross-Coupling

      Indole Synthesis by Conjugate Addition of Anilines to Activated Acetylenes and an Unusual Ligand-Free Copper(II)-Mediated Intramolecular Cross-Coupling (pages 14828–14840)

      Detian Gao and Prof. Dr. Thomas G. Back

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201202307

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      No ligands required! Intramolecular C-arylations of sulfonyl enamines, ynones, and ynoates were promoted by Cu(OAc)2 in alkaline DMF/H2O to provide substituted indoles without protection from air (see scheme). The starting material functioned as the ligand for its own cyclization. The process has been applied to the preparation of tricyclic products and to indole synthesis on solid supports.

    22. Synthetic Methods

      Copper-Catalyzed Three-Component Borylstannylation of Alkynes (pages 14841–14844)

      Yuki Takemoto, Prof. Dr. Hiroto Yoshida and Prof. Dr. Ken Takaki

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201202435

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      Borylstannylation: A copper–tricyclohexylphosphine complex was found to catalyse the three-component borylstannylation of alkynes with a diboron and a tin alkoxide to afford vic-borylstannylalkenes in a regio- and stereoselective manner. Synthetic utility of the resulting borylstannylation product was demonstrated by a three-step synthesis of (Z)-tamoxifen from commercially available substrates by successive Migita–Kosugi–Stille and Suzuki–Miyaura couplings (see scheme).

    23. Charge Separation

      Photoinduced Electron Transfer in an Amine–Corrole–Perylene Bisimide Assembly: Charge Separation over Terminal Components Favoured by Solvent Polarity (pages 14845–14859)

      Dr. Roman Voloshchuk, Prof. Dr. Daniel T. Gryko, Dr. Maciej Chotkowski, Adina I. Ciuciu and Dr. Lucia Flamigni

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201200744

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      Double electron transfer: An assembly consisting of four units, a meso-substituted corrole (C3), perylene bisimide (PI), and two electron-rich triphenylamine (DPA) units (see figure), is synthesized and its photophysical characteristics are determined. Excitation of the corrole (C3) or perylene bisimide (PI) units leads to the charge-separated state DPA-C3+-PI with a rate k>1011 s−1 in benzonitrile and dichloromethane and with k of the order of 1010 s−1 in toluene.

    24. Inhibitors

      Reversible and Efficient Inhibition of UDP-Galactopyranose Mutase by Electrophilic, Constrained and Unsaturated UDP-Galactitol Analogues (pages 14860–14866)

      Dr. Christophe Ansiaux, Inès N'Go and Prof. Stéphane P. Vincent

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201202302

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      Shedding inhibitors: UDP-Galactopyranose mutase (UGM) is a validated target for treating tuberculosis. Its mechanism involves formation of a key covalent FAD–substrate intermediate, 1. A series of electrophilic UDP-galactitols were synthesized and assayed as inhibitors or inactivators of UGM. Strong inhibitions were observed, especially with epoxide 2. Interestingly, none of the molecules displayed an irreversible inhibition mode.

    25. Supramolecular Chemistry

      Multicomponent Assembly of Macrocycles and Polymers by Coordination of Pyridyl Ligands to 1,4-Bis(benzodioxaborole)benzene (pages 14867–14874)

      Burcak Icli, Dr. Euro Solari, Dr. Benan Kilbas, Dr. Rosario Scopelliti and Prof. Kay Severin

      Article first published online: 27 SEP 2012 | DOI: 10.1002/chem.201202313

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      Macrocyclic or polymeric structures were formed from the reactions between 1,4-benzenediboronic acid, catechol, and di-, tri-, and tetratopic pyridyl ligands (see figure). These results demonstrate the utility of dative B[BOND]N bonds in structural supramolecular chemistry and crystal engineering.