Chemistry - A European Journal

Cover image for Vol. 19 Issue 48

November 25, 2013

Volume 19, Issue 48

Pages 16125–16475

  1. Cover Pictures

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
    1. You have free access to this content
      Cover Picture: Bis(tert-butylpyrene) Nanotweezers and Nanocalipers: Enhanced Extraction and Recognition Abilities for Single-Walled Carbon Nanotubes (Chem. Eur. J. 48/2013) (page 16125)

      Dr. Gang Liu, Dr. A. F. M. Mustafizur Rahman, Songpol Chaunchaiyakul, Prof. Takahide Kimura, Prof. Yuji Kuwahara and Prof. Naoki Komatsu

      Version of Record online: 18 NOV 2013 | DOI: 10.1002/chem.201390190

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      Sorting single-walled carbon nanotubes (SWNTs) attracts great attention in view of their applications. Recently, it was demonstrated that metallic SWNTs with diameters of 0.9–1.0 nm are highly enriched through molecular recognition. In their Full Paper on page 16221 ff., N. Komatsu et al. show that the host molecule, named “nanocalipers”, discriminates metallicity and diameter of SWNTs simultaneously to enrich limited kinds of metallic SWNTs. tert-Butyl substituents at pyrene moieties are found to enhance extraction and recognition abilities of the nanocalipers to SWNTs.

    2. You have free access to this content
      Back Cover: Phase-Reversal Emulsion Catalysis with CNT–TiO2 Nanohybrids for the Selective Oxidation of Benzyl Alcohol (Chem. Eur. J. 48/2013) (page 16480)

      Dr. Chang Yu, Liman Fan, Juan Yang, Yuanyuan Shan and Prof. Jieshan Qiu

      Version of Record online: 18 NOV 2013 | DOI: 10.1002/chem.201390193

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      Carbon nanotube–TiO2 nanohybrids have been fabricated with a simple and efficient method that allows for control over the carbon nanotube content. In the Communication on page 16192 ff., J. Qiu et al. report on the use of these nanohybrids as phase-reversal emulsion catalyst supports for ruthenium in the selective oxidation of benzyl alcohol to benzaldehyde.

  2. Graphical Abstract

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

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

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

      Synthesis of Cytotoxic Palmerolides (pages 16146–16168)

      Dr. Marilda P. Lisboa and Prof. Dr. Gregory B. Dudley

      Version of Record online: 4 NOV 2013 | DOI: 10.1002/chem.201302167

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      Can synthesis deliver? Chemical synthesis is the key to unlocking the chemotherapeutic potential of the palmerolides. This review covers the chemistry and biology of the palmerolides through early 2013, highlighting the evolution of a consensus strategy that could lead to cost-effective production of synthetic palmerolides. Palmerolide A is potently and selectively cytotoxic to certain melanomas. Its mechanism of action is poorly understood but likely involves inhibition of a transmembrane proton pump involved in regulation of cellular pH and metastasis.

  5. Communications

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

      Ordered Mesoporous Fe-Porphyrin-Like Architectures as Excellent Cathode Materials for the Oxygen Reduction Reaction in Both Alkaline and Acidic Media (pages 16170–16175)

      Dr. Aiguo Kong, Dr. Bing Dong, Xiaofang Zhu, Yingying Kong, Prof. Junliang Zhang and Prof. Yongkui Shan

      Version of Record online: 22 OCT 2013 | DOI: 10.1002/chem.201302104

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      Iron ORR: An ordered, mesoporous, Fe-porphyrin-like material was created through the nanocasting and pyrolysis of traditional Fe–N4 porphyrins. The resulting nonprecious metal electrocatalyst was used for the oxygen reduction reaction in both alkaline and acidic media.

    2. Tridentate Ligands

      Synthesis of Terminal Uranium(IV) Disulfido and Diselenido Compounds by Activation of Elemental Sulfur and Selenium (pages 16176–16180)

      Ellen M. Matson, Mitchell D. Goshert, John J. Kiernicki, Brian S. Newell, Phillip E. Fanwick, Prof. Matthew P. Shores, Prof. Justin R. Walensky and Prof. Suzanne C. Bart

      Version of Record online: 22 OCT 2013 | DOI: 10.1002/chem.201303095

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      Rare stakes: Terminal uranium(IV) disulfido and diselenido compounds, Tp*2U(E2) (E[DOUBLE BOND]S, Se), were synthesized by the activation of elemental chalcogens (see figure). Structural, spectroscopic, computational and magnetic studies of these species establish their tetravalency and highly polarized U[BOND]E bonds.

    3. Supramolecular Chemistry

      Probing the Effects of Ligand Isomerism in Chiral Luminescent Lanthanide Supramolecular Self-Assemblies: A Europium “Trinity Sliotar” Study (pages 16181–16186)

      Dr. Oxana Kotova, Dr. Jonathan A. Kitchen, Dr. Christophe Lincheneau, Dr. Robert D. Peacock and Prof. Thorfinnur Gunnlaugsson

      Version of Record online: 31 OCT 2013 | DOI: 10.1002/chem.201303660

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      “Trinity Sliotar” family: Chiral ligands containing pyridyl and naphthalene moieties were synthesized and characterized. These ligands were successfully used for the synthesis of EuIII bundles where chirality of the ligand is successfully transferred onto the lanthanide centre resulting in circularly polarized red luminescence.

    4. Molecular Dynamics

      The Role of Water-Based Hydrogen Atom Wires in Long-Range Electron-Transfer Reactions in Aqueous Media for the FeII–FeIII Self-Exchange and Related Systems (pages 16187–16191)

      Dr. Araceli G. Campaña, Dr. Elena Buñuel, Dr. Juan M. Cuerva and Prof. Diego J. Cárdenas

      Version of Record online: 4 NOV 2013 | DOI: 10.1002/chem.201301971

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      Extended reach: A calculated mechanism for long-range proton-coupled electron transfer (PCET, see picture) through an array of structured water molecules between FeIII–FeIII complexes accounts for the reaction enthalpy and kinetic isotope effect previously measured for this reaction. This mechanism may be general and occur for other hydroxo–metal complexes.

    5. Catalysis

      Phase-Reversal Emulsion Catalysis with CNT–TiO2 Nanohybrids for the Selective Oxidation of Benzyl Alcohol (pages 16192–16195)

      Dr. Chang Yu, Liman Fan, Juan Yang, Yuanyuan Shan and Prof. Jieshan Qiu

      Version of Record online: 7 NOV 2013 | DOI: 10.1002/chem.201300949

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      Mix it up: Carbon nanotube (CNT)–TiO2 nanohybrids with the potential to control the phase of an emulsion were successfully developed with a simple yet efficient method (see figure). When ruthenium was deposited on these CNT–TiO2 nanohybrid supports, they demonstrated catalytic potential for the selective oxidation of benzyl alcohol to benzaldehyde. The relationship between the emulsion properties and the catalytic mechanism is also discussed.

    6. Potassium Isopropoxide: For Sulfination It is the Only Base You Need! (pages 16196–16199)

      Mahmoud Sayah and Prof. Michael G. Organ

      Version of Record online: 31 OCT 2013 | DOI: 10.1002/chem.201303756

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      PEPPSI max: KOiPr has been identified as the key ingredient for Pd-catalyzed sulfination (see scheme). Potassium is essential to keep the thiol concentration low, and isopropoxide is necessary for precatalyst activation and to break up Pd-sufide-based resting states. Together with the reactive Pd-PEPPSI-IPentCl o-picoline catalyst, this system couples profoundly deactivated partners at RT that other catalysts cannot accomplish in refluxing toluene.

    7. Asymmetric Synthesis

      Enantioselective Protonation of Alkenyl Trifluoroacetates Catalyzed by Chiral Tin Methoxide (pages 16200–16203)

      Prof. Dr. Akira Yanagisawa, Takuya Sugita and Prof.Dr. Kazuhiro Yoshida

      Version of Record online: 31 OCT 2013 | DOI: 10.1002/chem.201302975

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      Go catalytic! A catalytic enantioselective protonation of alkenyl trifluoroacetates was achieved by using an in situ generated chiral tin bromide methoxide as the chiral catalyst in the presence of methanol (see scheme). Optically active ketones containing a tertiary stereogenic center at the α-position were obtained with enantioselectivities of up to 94 % ee.

    8. Molecular Devices

      Synthesis and Photochemical Isomerization of a Propeller-Shaped Molecular Switch (pages 16204–16208)

      Paula Estey, Alex Bubar, Prof. Andreas Decken, Prof. Larry Calhoun and Prof. Sara Eisler

      Version of Record online: 31 OCT 2013 | DOI: 10.1002/chem.201302879

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      Switched on! A tetra-stable switch has been synthesized in two steps, utilizing photoresponsive isoindolinone moieties. Sequential E–Z isomerization induced by 365 nm light results in a propeller switching action that is reversible using 458 nm light, acid, and high temperature (see scheme).

    9. Asymmetric Synthesis

      Highly Enantioselective Hydrogenation of 1-Alkylvinyl Benzoates: A Simple, Nonenzymatic Access to Chiral 2-Alkanols (pages 16209–16212)

      Patryk Kleman, Pedro J. González-Liste, Dr. Sergio E. García-Garrido, Dr. Victorio Cadierno and Dr. Antonio Pizzano

      Version of Record online: 4 NOV 2013 | DOI: 10.1002/chem.201303500

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      Going chiral! Highly enantioselective catalytic hydrogenations of enol esters 1 by using a Rh catalyst bearing a P[BOND]OP ligand are described (see scheme; NBD=norbornadiene). The catalytic system has a broad scope and allows the preparation of a wide range of chiral esters 2 bearing diverse alkyls or a benzyl group with high enantioselectivities. These esters can easily be converted in highly enantioenriched 2-alkanols.

      Corrected by:

      Corrigendum: Corrigendum: Highly Enantioselective Hydrogenation of 1-Alkylvinyl Benzoates: A Simple, Nonenzymatic Access to Chiral 2-Alkanols

      Vol. 20, Issue 41, 13056, Version of Record online: 26 SEP 2014

  6. Full Papers

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

      Luminescence Color-Tuning through Polymorph Doping: Preparation of a White-Emitting Solid from a Single Gold(I)–Isocyanide Complex by Simple Precipitation (pages 16214–16220)

      Dr. Tomohiro Seki, Sayaka Kurenuma and Prof. Dr. Hajime Ito

      Version of Record online: 7 NOV 2013 | DOI: 10.1002/chem.201303394

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      Color-tuned crystals: A powder formed by rapid precipitation of 2-benzothiophenyl(4-methoxyphenyl isocyanide)gold(I) exhibits white photoluminescence, whereas slow crystallization of the same compound affords three different pure polymorphic crystals with blue, green, and orange emissions. Spectroscopic and X-ray diffraction analyses indicate that the new “polymorph doping” approach requires multiple polymorphs to exhibit a white emission of the powder (see figure).

    2. Carbon Nanotubes

      Bis(tert-butylpyrene) Nanotweezers and Nanocalipers: Enhanced Extraction and Recognition Abilities for Single-Walled Carbon Nanotubes (pages 16221–16230)

      Dr. Gang Liu, Dr. A. F. M. Mustafizur Rahman, Songpol Chaunchaiyakul, Prof. Takahide Kimura, Prof. Yuji Kuwahara and Prof. Naoki Komatsu

      Version of Record online: 7 NOV 2013 | DOI: 10.1002/chem.201302799

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      Nanotweezers and nanocalipers: A tert-Butyl substituent at pyrene was found to significantly enhance the extraction and recognition abilities of dipyrene nanotweezers and nanocalipers, resulting in enrichment of (6,5)-SWNTs and metallic SWNTs, respectively (see picture; SWNTs=single-walled carbon nanotubes).

    3. Photoactive Catalysts

      A Photoreducible Copper(II)-Tren Complex of Practical Value: Generation of a Highly Reactive Click Catalyst (pages 16231–16239)

      Dr. Lydie Harmand, Romain Lambert, Dr. Luca Scarpantonio, Dr. Nathan D. McClenaghan, Dr. Dominique Lastécouères and Dr. Jean-Marc Vincent

      Version of Record online: 14 OCT 2013 | DOI: 10.1002/chem.201302032

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      PET-cat: A highly active CuI click catalyst is generated upon irradiation at 365 nm (TLC lamp) of the CuII precatalyst 1. The reduction is driven by a photoinduced electron transfer (PET) process implying a benzophenone-like ketoprofenate chromophore. The influence of the solvent, prolonged irradiation time, and O2 on the reduction process, and the fate and reactivity of the photogenerated CuI species is reported (see figure).

    4. Halogen Bonding

      Supramolecular Hierarchy among Halogen-Bond Donors (pages 16240–16247)

      Prof. Dr. Christer B. Aakeröy, Dr. Michele Baldrighi, Dr. John Desper, Prof. Dr. Pierangelo Metrangolo and Prof. Dr. Giuseppe Resnati

      Version of Record online: 15 OCT 2013 | DOI: 10.1002/chem.201302162

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      Joining the ranks: The halogen-bonding strength of iodo and bromo analogues of ethynyl, perfluorinated, and phenyl-based donors are compared theoretically, through the electrostatic potential surfaces of the donors, and experimentally, through the formation of co-crystals by co-grinding, in order to provide a “supramolecular ranking” of these moieties for crystal engineering applications (see graphic).

    5. Nucleosides

      Unzipping Nucleoside Channels by Means of Alcohol Disassembly (pages 16248–16255)

      Julie P. Vanegas, Lucas E. Peisino, Dr. Salvador Pocoví-Martínez, Dr. Ramón J. Zaragozá, Dr. Elena Zaballos-García and Dr. Julia Pérez-Prieto

      Version of Record online: 18 OCT 2013 | DOI: 10.1002/chem.201302912

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      Feeling tipsy: Aggregates of adenosine-capped gold nanoparticles are highly stable in low-polar solvents (see figure). Their stability is not broken in the presence of other nucleosides or DNA bases, but only by alcohols that can penetrate the assembled structure.

    6. Amino Acids

      Efficient Access to Enantiopure γ4-Amino Acids with Proteinogenic Side-Chains and Structural Investigation of γ4-Asn and γ4-Ser in Hybrid Peptide Helices (pages 16256–16262)

      Sandip V. Jadhav, Rajkumar Misra, Sumeet K. Singh and Dr. Hosahudya N. Gopi

      Version of Record online: 21 OCT 2013 | DOI: 10.1002/chem.201302732

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      Hybrid γ-peptide foldamers: An efficient synthesis of unprotected γ4-amino acids with proteinogenic side-chains is reported, and their stereochemical purity and crystal conformations are studied. Utilizing these amino acids, two short α,γ-hybrid hexapeptides containing γ4-Asn and γ4-Ser were designed, prepared by solid-phase synthesis, and their conformations in single crystals were studied (see figure).

    7. Supramolecular Chemistry

      Chirality Induction by Formation of Assembled Structures Based on Anion-Responsive π-Conjugated Molecules (pages 16263–16271)

      Prof. Dr. Hiromitsu Maeda, Wataru Hane, Dr. Yuya Bando, Dr. Yoshitaka Terashima, Dr. Yohei Haketa, Hiroshi Shibaguchi, Prof. Dr. Tsuyoshi Kawai, Prof. Dr. Masanobu Naito , Dr. Kazuto Takaishi , Prof. Dr. Masanobu Uchiyama  and Dr. Atsuya Muranaka 

      Version of Record online: 21 OCT 2013 | DOI: 10.1002/chem.201301737

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      Opposite signs of the circular dichroism (CD) and circularly polarized luminescence (CPL) spectral patterns of ion-pair-based assemblies and anion-free assemblies of anion-responsive π-conjugated compounds bearing chiral alkyl chains (see figure) suggest that anion binding and subsequent ion pairing change the chirality of the assembly modes.

    8. Computer Chemistry

      Realistic Energy Surfaces for Real-World Systems: An IMOMO CCSD(T):DFT Scheme for Rhodium-Catalyzed Hydroformylation with the 6-DPPon Ligand (pages 16272–16281)

      Urs Gellrich, Dr. Daniel Himmel, Prof. Dr. Markus Meuwly and Prof. Dr. Bernhard Breit

      Version of Record online: 14 OCT 2013 | DOI: 10.1002/chem.201302132

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      A two-layer model (CCSD(T):DFT) in the framework of an integrated molecular orbital plus molecular orbital (IMOMO) scheme (see figure) was evaluated for rhodium-catalyzed hydroformylation with the self-assembling 6-diphenylphosphinopyridine-(2H)-1-one ligand (6-DPPon). By applying the energetic-span model, an excellent match between the calculated and experimentally observed turnover frequencies was achieved.

    9. Cellulose

      The Electronic Nature of the 1,4-β-Glycosidic Bond and Its Chemical Environment: DFT Insights into Cellulose Chemistry (pages 16282–16294)

      Claudia Loerbroks, Dr. Roberto Rinaldi and Prof. Dr. Walter Thiel

      Version of Record online: 18 OCT 2013 | DOI: 10.1002/chem.201301366

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      Strong nature: The electronic nature of the 1,4-β-glycosidic bond and its chemical environment is examined by DFT calculations on cellobiose. The results reveal that cellulose is protected against hydrolysis not only by the hydrogen-bond network, as currently accepted, but also by the electronic structure, in which the anomeric effect plays a key role.

    10. Helicenes

      Synthesis, Crystal Structure and Photophysical Properties of Pyrene–Helicene Hybrids (pages 16295–16302)

      Anne-Catherine Bédard, Anna Vlassova, Augusto C. Hernandez-Perez, André Bessette, Prof. Dr. Garry S. Hanan, Matthew A. Heuft and Prof. Dr. Shawn K. Collins

      Version of Record online: 21 OCT 2013 | DOI: 10.1002/chem.201301431

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      One-way stretch: Novel helically chiral aromatics resulting from fusion of pyrene and [4]- or [5]helicene have been synthesised using Cu-based photoredox catalysis in batch and in continuous flow (see diagram). This extension of the skeleton along the y axis results in an increase in the π surface. The solid-state structure, UV/Vis absorption and fluorescence spectroscopy of the pyrene–helicene hybrids are compared to that of the parent [5]helicene.

    11. Triblock Polyphiles

      Triblock Polyphiles through Click Chemistry: Self-Assembled Thermotropic Cubic Phases Formed by Micellar and Monolayer Vesicular Aggregates (pages 16303–16313)

      Xiaoping Tan, Leiyang Kong, Heng Dai, Prof. Dr. Xiaohong Cheng, Prof. Dr. Feng Liu and Prof. Dr. Carsten Tschierske

      Version of Record online: 14 OCT 2013 | DOI: 10.1002/chem.201301538

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      Core length makes the difference: Triblock polyphiles, obtained by click chemistry, self-assemble into equation image cubic liquid-crystalline phases composed of spherical objects with different structures. The spheres of compounds I are small and represent micellar aggregates (CubI), whereas those of compounds II and III with longer cores are much larger and can be considered to be monolayer vesicular core/shell aggregates (CubSph) with a relatively large polar interior composed of a different material to the continuum (see figure).

    12. Molecular Recognition

      Probing Helical Hydrophobic Binding Sites in Branched Starch Polysaccharides Using NMR Spectroscopy (pages 16314–16320)

      Dr. Sophie R. Beeren, Dr. Sebastian Meier and Prof. Ole Hindsgaul

      Version of Record online: 10 OCT 2013 | DOI: 10.1002/chem.201302213

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      Complexing carbohydrates: Hydrophobic binding sites in branched starch polysaccharides are examined with an amphiphilic molecular probe. The probe undergoes substantial conformational rearrangement upon polysaccharide binding in aqueous solution, resulting in dramatic chemical shift changes when observed by NMR spectroscopy (see figure).

    13. Rare-Earth-Metal Complexes

      Rare-Earth-Metal Alkylaluminates Supported by N-Donor-Functionalized Cyclopentadienyl Ligands: C[BOND]H Bond Activation and Performance in Isoprene Polymerization (pages 16321–16333)

      Lars N. Jende, Dr. Cäcilia Maichle-Mössmer and Prof. Dr. Reiner Anwander

      Version of Record online: 21 OCT 2013 | DOI: 10.1002/chem.201302388

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      A rare breed: Amino-functionalized half-sandwich rare-earth-metal bis(tetramethylaluminate)s show competitive donor coordination and C[BOND]H bond activation depending on the rigidity of the linker, additional donor molecules, LnIII size, and temperature.

    14. Reaction Mechanisms

      Reactivity of Yttrium Carboxylates Toward Alkylaluminum Hydrides (pages 16334–16341)

      Christoph Schädle, Dr. Andreas Fischbach, Dr. Eberhardt Herdtweck, Prof. Dr. Karl W. Törnroos and Prof. Dr. Reiner Anwander

      Version of Record online: 21 OCT 2013 | DOI: 10.1002/chem.201302944

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      Y do butterflies suddenly appear: Yttrocene-benzoate complex [Cp*2Y(OOCArMe)] allows for the modeling of crucial reaction pathways in Ziegler catalysis that involve rare-earth-metal carboxylates and diisobutylaluminum hydride (see scheme).

    15. Chiral Carbanions

      Investigation of Functionalized α-Chloroalkyllithiums for a Stereospecific Reagent-Controlled Homologation Approach to the Analgesic Alkaloid (−)-Epibatidine (pages 16342–16356)

      Dr. Christopher R. Emerson, Dr. Lev N. Zakharov and Prof. Dr. Paul R. Blakemore

      Version of Record online: 14 OCT 2013 | DOI: 10.1002/chem.201302511

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      Teetering on the brink of instability, α-chloroalkyllithiums can be synthetically useful providing that their high reactivity is carefully managed. A series of these carbenoids bearing functionalized side-chains were investigated for a stereospecific reagent-controlled homologation (StReCH) approach to the analgesic alkaloid (−)-epibatidine (FG=functional group; Bpin=B-pinacol).

    16. Bioactive Peptides

      The N-Terminal Nonapeptide of Cephaibols A and C: A Naturally Occurring Example of Mismatched Helical Screw-Sense Control (pages 16357–16365)

      Ugo Orcel, Dr. Matteo De Poli, Dr. Marta De Zotti and Prof. Jonathan Clayden

      Version of Record online: 9 OCT 2013 | DOI: 10.1002/chem.201302648

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      L-to-D switching: The N-terminus of the fungal-peptide antibiotics, the cephaibols, is a right-handed helix in the crystalline state, but a mixture of left- and right-handed helices in solution. Switching the configuration of one of the amino acids nearest the N-terminus from L to D leads, by contrast, to a stable left-handed helix in solution (see graphic).

    17. Asymmetric Synthesis

      Improved Synthesis of Cyclic Tertiary Allylic Alcohols by Asymmetric 1,2-Addition of AlMe3 to Enones (pages 16366–16373)

      Dipl.-Chem. Andreas Kolb, Wei Zuo, Dr. Jürgen Siewert, Dr. Klaus Harms and Prof. Dr. Paultheo von Zezschwitz

      Version of Record online: 24 OCT 2013 | DOI: 10.1002/chem.201303061

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      The silver trick: The efficiency of Rh/binap (binap=2,2′-bis(diphenylphosphino)-1,1′-binaphthyl) catalysed asymmetric 1,2-addition of organoaluminium reagents to cyclic enones is greatly increased in the presence of AgBF4. However, subtle effects that depend on the amounts of chloride ion and diene ligand present in the reaction mixture were observed (see scheme).

    18. Micelles

      Zwitterionic Moieties from the Huisgen Reaction: A Case Study with Amphiphilic Dendritic Assemblies (pages 16374–16381)

      Rajasekhar R. Ramireddy, Dr. Ayyagari V. Subrahmanyam and Prof. S. Thayumanavan

      Version of Record online: 22 OCT 2013 | DOI: 10.1002/chem.201302442

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      Point and click: A simple and elegant method to install triazole-based zwitterionic moieties onto macromolecules by Huisgen click chemistry is presented. Amphiphilic biaryl dendrons with triazole based zwitterionic functionalities as hydrophilic groups were designed and synthesized (see diagram). Their ability to form self-assembled aggregates was demonstrated by fluorescence, DLS and TEM studies.

    19. Optical Activity

      Water-Dependent Optical Activity Inversion of Chiral DNA–Silica Assemblies (pages 16382–16388)

      Ben Liu, Yuanyuan Cao, Yingying Duan and Prof. Shunai Che

      Version of Record online: 18 OCT 2013 | DOI: 10.1002/chem.201303073

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      Just add water: The optical activity of enantiomeric chiral DNA–silica assemblies (CDSAs) was inverted by the addition of water. This was attributed to the dual and opposite chirality of DNA packing. The effects of transversal and longitudinal interactions between DNAs with dual chirality due to the structural states under dry and wet conditions were considered to be the origin for the inversion in optical activity (see figure).

    20. Biomimetic Synthesis

      Bio-Inspired Formal Synthesis of Hirsutellones A–C Featuring an Electrophilic Cyclization Triggered by Remote Lewis Acid-Activation (pages 16389–16393)

      Xu-Wen Li, Alexandre Ear, Lukas Roger, Dr. Nassima Riache, Alexandre Deville and Dr. Bastien Nay

      Version of Record online: 18 OCT 2013 | DOI: 10.1002/chem.201303570

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      Inspired by nature: A bio-inspired strategy was used to complete the formal synthesis of hirsutellones A–C. After synthesizing a linear polyene activated at both ends, the electrophilic cyclization of the silyl enol ether on the allyl acetate strand stereoselectively afforded ring C, followed by intramolecular Diels–Alder reaction to obtain the tricyclic core (see scheme). The stereoselective reduction of the resulting ketone was critical to the strategy.

    21. Crystal Structures

      Breathing Effect in a Cobalt Phosphonate upon Dehydration/Rehydration: A Single-Crystal-to-Single-Crystal Study (pages 16394–16402)

      Tao Zheng, Prof. Dr. Juan M. Clemente-Juan, Prof. Dr. Jing Ma, Prof. Dr. Lin Dong, Dr. Song-Song Bao, Dr. Jian Huang, Prof. Dr. Eugenio Coronado and Prof. Dr. Li-Min Zheng

      Version of Record online: 21 OCT 2013 | DOI: 10.1002/chem.201302514

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      Breathe deeply: Layered cobalt phosphonates [Co2(2,2′-bpy)2(H2O)(pbtcH)] and [Co2(H2O)(pbtcH)(phen)2] (pbtcH5=5-phosphonatophenyl-1,2,4-tricarboxylic acid, 2,2′-bpy=2,2′-bipyridine, phen=1,10-phenanthroline) can experience a reversible single-crystal-to-single-crystal transformation upon dehydration and rehydration (see figure). A breathing effect is observed for [Co2(2,2′-bpy)2(H2O)(pbtcH)].

    22. Reaction Kinetics

      Ring-Closing Metathesis Reactions: Interpretation of Conversion–Time Data (pages 16403–16414)

      Dr. Vasco Thiel, Dr. Klaus-Jürgen Wannowius, Dipl.-Ing. Christiane Wolff, Prof. Dr. Christina M. Thiele and Prof. Dr. Herbert Plenio

      Version of Record online: 14 OCT 2013 | DOI: 10.1002/chem.201204150

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      Analyzing substrate conversion: Based on a simple formal kinetic model, conversion–time data for ring-closing metathesis reactions can be analyzed as schematically shown to provide rate constants for precatalyst activation, the catalytic reaction itself, and the deactivation of catalytically active species.

    23. Carbon Nanotubes

      Surfactant Hydrogels for the Dispersion of Carbon-Nanotube-Based Catalysts (pages 16415–16423)

      Dr. Antonello Di Crescenzo, Dr. Luca Bardini, Dr. Bruna Sinjari, Dr. Tonino Traini, Dr. Lisa Marinelli, Dr. Mauro Carraro, Prof. Raimondo Germani, Dr. Pietro Di Profio, Prof. Sergio Caputi, Prof. Antonio Di Stefano, Prof. Marcella Bonchio, Prof. Francesco Paolucci and Prof. Antonella Fontana

      Version of Record online: 21 OCT 2013 | DOI: 10.1002/chem.201302704

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      Off the wall: Single- and multiwalled carbon nanotubes (CNTs) were successfully dispersed in a surfactant hydrogel without the need for chemical modification (see figure). The obtained positively charged CNTs were shown to be able to incorporate the negatively charged catalyst Ru4POM (POM=polyoxometalate) at the elected loading.

    24. Conjugate Addition

      Chiral-Zn(NTf2)2-Complex-Catalyzed Diastereo- and Enantioselective Direct Conjugate Addition of Arylacetonitriles to Alkylidene Malonates (pages 16424–16430)

      Jingjing Yao, Prof. Dr. Xiaohua Liu, Peng He, Yin Zhu, Xiangjin Lian, Dr. Lili Lin and Prof. Dr. Xiaoming Feng

      Version of Record online: 15 OCT 2013 | DOI: 10.1002/chem.201302122

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      Direct route: Chiral N,N′-dioxide/Zn(NTf2)2 complexes promoted the direct asymmetric conjugate addition of arylacetonitriles to alkylidene malonates under mild conditions in moderate-to-good yields with high diastereo- and enantioselectivities (see scheme).

    25. Thermochemistry

      Group Additive Values for the Gas-Phase Standard Enthalpy of Formation, Entropy and Heat Capacity of Oxygenates (pages 16431–16452)

      Paschalis D. Paraskevas, Dr. Maarten K. Sabbe, Prof. Dr. Marie-Françoise Reyniers, Prof. Dr. Nikos Papayannakos and Prof. Dr. Guy B. Marin

      Version of Record online: 10 OCT 2013 | DOI: 10.1002/chem.201301381

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      Predicting thermochemistry: Obtaining accurate thermochemical data for oxygenates and particularly oxygenate radicals in large radical-reaction networks, such as those in biomass pyrolysis, is challenging. To predict these data, a large and accurate set of group additive values (see figure) and hydrogen bond increment values have been determined using high-level CBS-QB3 quantum chemical calculations.

    26. Amination

      Arene C[BOND]H Amination at Nickel in Terphenyl–Diphosphine Complexes with Labile Metal–Arene Interactions (pages 16453–16460)

      Dr. David E. Herbert, Nadia C. Lara and Prof. Theodor Agapie

      Version of Record online: 14 OCT 2013 | DOI: 10.1002/chem.201302539

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      Put a ring on it: The utilization of a meta-terphenyl diphosphine ligand leads to labile metal-arene interactions in Ni complexes in various oxidation states and coordination environments. When these complexes are treated with group-transfer reagents, such as diazoalkanes, sulfur ylides, or azides, various types of ligand-centered reactivity were observed, including methylidene insertion into a P[BOND]C bond and amination of an arene C[BOND]H bond (see scheme; Ad=adamantyl).

    27. C[BOND]H Activation

      Rhodium-Catalyzed Oxidative C–H Activation/Cyclization for the Synthesis of Phosphaisocoumarins and Phosphorous 2-Pyrones (pages 16461–16468)

      Youngchul Park, Jungmin Seo, Sangjune Park, Prof. Dr. Eun Jeong Yoo and Prof. Dr. Phil Ho Lee

      Version of Record online: 10 OCT 2013 | DOI: 10.1002/chem.201302652

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      Putting phosphorous in the ring: Aryl phosphinic acids and alkenyl phosphonic monoesters can be cyclized with alkynes in the presence of a catalytic amount of a rhodium catalyst to give phosphaisocoumarins and phosphorous 2-pyrones, respectively (see scheme).

    28. Solid-State 14N NMR

      Rapid Acquisition of 14N Solid-State NMR Spectra with Broadband Cross Polarization (pages 16469–16475)

      Kristopher J. Harris, Stanislav L. Veinberg, Christopher R. Mireault, Adonis Lupulescu, Lucio Frydman and Robert W. Schurko

      Version of Record online: 10 OCT 2013 | DOI: 10.1002/chem.201301862

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      Expeditious enhancement: High quality ultra-wideline solid-state 14N NMR spectra can be rapidly acquired with broadband cross polarization (CP) and CPMG echo trains. Broadband CP methods yield 14N NMR spectra with 4–10 times the signal-to-noise ratio of conventional experiments in which the 14N nuclei are excited directly (BRAIN-CP and direct-excitation experiments conducted on α-glycine are compared in the figure).

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