Chemistry - A European Journal

Cover image for Vol. 18 Issue 28

July 9, 2012

Volume 18, Issue 28

Pages 8549–8847

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Concept
    7. Communications
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      Cover Picture: Pressure-Induced Enhancement of Magnetic-Ordering Temperature in an Organic Radical to 70 K: A Magnetostructural Correlation (Chem. Eur. J. 28/2012) (page 8549)

      Richard I. Thomson, Dr. Christopher M. Pask, Dr. Gareth O. Lloyd, Prof. Masaki Mito and Prof. Jeremy M. Rawson

      Version of Record online: 3 JUL 2012 | DOI: 10.1002/chem.201290115

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      The organic radical β-p-NCC6F4CNSSN. exhibited an enhancement in magnetic-ordering temperature to 70 K under pressure. Structure solution from variable pressure powder X-ray diffraction (PXRD) studies coupled with DFT calculations revealed a strong magnetostructural correlation between the intermolecular S⋅⋅⋅N contacts and magnetic-ordering temperature. For more details, see the Full Paper by J. M. Rawson et al. on page 8629 ff.

  2. Inside Cover

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Concept
    7. Communications
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    1. Inside Cover: A Nano-Fibrillated Mesoporous Carbon as an Effective Support for Palladium Nanoparticles in the Aerobic Oxidation of Alcohols “on Pure Water” (Chem. Eur. J. 28/2012) (page 8550)

      Prof. Dr. Babak Karimi, Dr. Hesam Behzadnia, Dr. Mihnea Bostina and Prof. Dr. Hojatollah Vali

      Version of Record online: 3 JUL 2012 | DOI: 10.1002/chem.201290116

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      The selective aerobic oxidation of alcohols to the corresponding carbonyl compounds occurs effectively “on water” in the presence of Pd nanoparticles (blue circles) supported on a novel nano-fibrillated mesoporous carbon (Pd@IFMC). The 3D-electron tomogram of Pd@IFMC is depicted on a drop of water (as the background) to highlight the “green” feature of the process. For more information see the Full Paper by B. Karimi et al. on page 8634 ff.

  3. Graphical Abstract

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

    1. Top of page
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    4. Graphical Abstract
    5. News
    6. Concept
    7. Communications
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  5. Concept

    1. Top of page
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    4. Graphical Abstract
    5. News
    6. Concept
    7. Communications
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    1. Dynamic Combinatorial Chemistry

      Dynamic Mixtures: Challenges and Opportunities for the Amplification and Sensing of Scents (pages 8568–8577)

      Dr. Andreas Herrmann

      Version of Record online: 15 MAY 2012 | DOI: 10.1002/chem.201200668

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      Mixtures are annoying, but nevertheless the distinction of odorant mixtures is an important task in the everyday life of most species. Dynamic combinatorial/covalent chemistry impacts the emission and reception of bioactive volatile compounds at the air–water interface and might thus become a key concept in gaining fundamental insight into the molecular recognition of bioactive compound mixtures.

  6. Communications

    1. Top of page
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    4. Graphical Abstract
    5. News
    6. Concept
    7. Communications
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    1. Immunoassays

      A C-Linked Disaccharide Analogue of Thomsen–Friedenreich Epitope Induces a Strong Immune Response in Mice (pages 8578–8582)

      Prof. Loay Awad, Dr. Rime Madani, Dr. Annabelle Gillig, Dr. Maria Kolympadi, Dr. Maria Philgren, Dr. Andreas Muhs, Dr. Catherine Gérard and Prof. Pierre Vogel

      Version of Record online: 12 JUN 2012 | DOI: 10.1002/chem.201200364

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      Anticancer vaccine: Antigen 2 made out of a tripeptide of β-D-Galp-(1[RIGHTWARDS ARROW]3)-CH2-α-D-GalNAc-O-Ser and conjugated with keyhole limpet hemocyanin (KLH) protein induced an early and strong immune response (IgG antibodies) in mice. Antigen 3 made out of an α-C-galactoside analogue did not induce such an immune response (see scheme).

    2. Homogeneous Catalysis

      Trifluoromethylation of Allylsilanes under Copper Catalysis (pages 8583–8587)

      Dr. Satoshi Mizuta, Oscar Galicia-López, Keary M. Engle, Stefan Verhoog, Dr. Katherine Wheelhouse, Dr. Gerasimos Rassias and Prof. Véronique Gouverneur

      Version of Record online: 12 JUN 2012 | DOI: 10.1002/chem.201201707

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      Branched allylic CF3 products are accessible by copper-catalyzed trifluoromethylation of allylsilanes with the Togni reagent I. The silyl group is critical to control the outcome of this reaction because in its absence, a product of addition between the alkene and the Togni reagent is formed preferentially. The reaction is inhibited with 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and is likely to operate via multiple reaction pathways.

    3. Crown Compounds

      New Neutral Reaction System with Crown Ether–KCl Complexes in Aqueous Solution (pages 8588–8590)

      Dr. Seiji Shirakawa, Dr. Lijia Wang, Atsuyuki Kasai and Prof. Dr. Keiji Maruoka

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201201107

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      Chiral auxiliaries: A new neutral reaction system with lipophilic [18]crown-6 derivatives and with an aqueous KCl solution has been successfully utilized for several conjugate-addition reactions (see scheme). The ring size, lipophilicity of the crown ether, and the presence of water are crucial to promote the reaction efficiently. The reaction system can also be applied to asymmetric conjugate addition of the chiral acyloxazolidinone with excellent diastereoselectivity.

    4. Cycloaddition Reactions

      C[BOND]O Versus C[BOND]C Bond Cleavage: Selectivity Control in Lewis Acid Catalyzed Chemodivergent Cycloadditions of Aryl Oxiranyldicarboxylates with Aldehydes, and Theoretical Rationalizations of Reaction Pathways (pages 8591–8595)

      Zuliang Chen, Ziqi Tian, Jieming Zhang, Prof. Dr. Jing Ma and Prof. Dr. Junliang Zhang

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201201453

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      A clean break: Lewis acid catalyzed chemodivergent [3+2] cycloadditions of aryl oxiranyldicarboxylates with aldehydes are revealed, in which the C[BOND]C or C[BOND]O bond cleavage of oxiranes can be controlled by the use of Ni(ClO4)2 or Sn(OTf)2 catalysts (see scheme). Possible reaction pathways for these transformations are demonstrated by theoretical calculations.

    5. Carbonylation

      Palladium-Catalyzed Synthesis of Phthalazinones: Efficient Carbonylative Coupling of 2-Bromobenzaldehydes and Hydrazines (pages 8596–8599)

      Dr. Xiao-Feng Wu, Dr. Helfried Neumann, Stephan Neumann and Prof. Dr. Matthias Beller

      Version of Record online: 15 JUN 2012 | DOI: 10.1002/chem.201200267

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      Phthalazinones made easy! A new, straightforward methodology for the carbonylative synthesis of phthalazinones has been established. Starting from readily available 2-bromobenzaldehydes or 2-bromoacetophenone and hydrazines, a variety of phthalazinones have been produced in good isolated yields (see scheme).

    6. Cascade Reactions

      Platinum-Catalyzed Cyclization/[1,2]-Alkyl Migration/Allyl Shift/Cyclization Cascade of Epoxy Alkynyl Allyl Ethers: A Step-Economical Route to Spirobenzo[h]chromanones (pages 8600–8604)

      Dr. Yan-Fang Yang, Xing-Zhong Shu, Jian-Yi Luo, Shaukat Ali and Prof. Dr. Yong-Min Liang

      Version of Record online: 8 JUN 2012 | DOI: 10.1002/chem.201200126

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      In tandem: A PtI4-catalyzed tandem reaction of epoxy alkynyl allyl ethers involving a cyclization, [1,2]-alkyl migration, O[RIGHTWARDS ARROW]C allyl shift, aromatic cyclization sequence has been achieved to synthesize spirobenzo[h]chromanones. The reaction simultaneously forms two adjacent stereocenters, one of which is a quaternary carbon atom (see scheme).

    7. Boranes

      Observation of Elementary Steps in the Catalytic Borane Dehydrocoupling Reaction (pages 8605–8609)

      Prof. Dr. Holger Braunschweig, Dipl.-Chem. Peter Brenner, Dr. Rian D. Dewhurst, Dr. Frank Guethlein, Dr. J. Oscar C. Jimenez-Halla, Dr. Krzysztof Radacki, Dr. Justin Wolf and Lisa Zöllner

      Version of Record online: 15 JUN 2012 | DOI: 10.1002/chem.201201739

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      Step-by-step: Elementary steps of the catalytic borane dehydrocoupling reaction have been observed by using platinum complexes, and key intermediates have been isolated. By combining these observations with DFT calculations, a global mechanism for the catalysis was proposed, and the experimentally observed effect of rigid versus flexible phosphine ligands on the reaction was explained (see scheme).

    8. Photochemistry

      Extremely Efficient and Reversible Visible-Light Photochromism and Accompanying Switch of Electronic Communication in N-Phenylcarbazole-Appended Diethynylethene (pages 8610–8613)

      Mikihiro Hayashi, Dr. Ryota Sakamoto and Prof. Dr. Hiroshi Nishihara

      Version of Record online: 13 JUN 2012 | DOI: 10.1002/chem.201200794

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      Photoisomerization: N-phenylcarbazole-conjugated dimethyl 2,3-diethynylfumarate/maleate, E/Z-4, shows highly efficient and reversible visible-light E/Z photoisomerization (Φtotal=0.40) upon excitation with an intramolecular charge-transfer band. This photochromism induces switching of electronic communication between the two N-phenylcarbazole moieties in the one-electron oxidized mixed-valent state (see scheme).

    9. Metal–Organic Frameworks

      Intrinsic Green Phosphor Containing a {Y5O22} Pentamer Unit and a Carbonate Ligand Generated In Situ from Squaric Acid (pages 8614–8616)

      Dr. Yu-Ting Huang, Yi-Chun Lai and Prof. Sue-Lein Wang

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201200509

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      An unexpected green phosphor! The promising activator-free yttrium metal–organic framework (MOF) [Y5(OH)6(HCO2)3(CO3)2-(C4O4)] 2.5 H2O consists of unique {Y5O22} pentamers and four types of ligands, the carbonate group of which was unprecedentedly in situ generated from squaric acid. This pure yttrium–MOF compound displays intrinsic green light and has proven to be the first hybrid-yttrium-host lattice to achieve near-white-light solely through Eu3+ doping (see figure).

    10. Anticancer Drugs

      Ruthenium(II)–Arene Complexes with Strong Fluorescence: Insight into the Underlying Mechanism (pages 8617–8621)

      Dr. Qianxiong Zhou, Dr. Wanhua Lei, Yongjie Chen, Dr. Chao Li, Prof. Yuanjun Hou, Prof. Baowen Zhang and Prof. Xuesong Wang

      Version of Record online: 14 JUN 2012 | DOI: 10.1002/chem.201200960

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      Still fluorescent upon coordination to Ru: [(η6-p-cymene)Ru(dppn)(py)]2+ (dppn=4,5,9,16-tetraaza-dibenzo[a,c]naphthacene) is highly fluorescent due to the coordinated dppn with a fluorescence quantum yield of 0.31 in acetonitrile, which is nearly the same as free dppn (0.33) and one of the highest of all luminescent RuII complexes. The underlying mechanism may shed light on the development of RuII arene-based anticancer theranostic agents (see scheme).

  7. Full Papers

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Concept
    7. Communications
    8. Full Papers
    9. Preview
    1. Supramolecular Chemistry

      From Bola-amphiphiles to Supra-amphiphiles: The Transformation from Two-Dimensional Nanosheets into One-Dimensional Nanofibers with Tunable-Packing Fashion of n-Type Chromophores (pages 8622–8628)

      Kai Liu, Yuxing Yao, Chao Wang, Yu Liu, Prof. Zhibo Li and Prof. Xi Zhang

      Version of Record online: 20 JUN 2012 | DOI: 10.1002/chem.201200898

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      Supra-tuned: With a rational design of the supra-amphiphiles, it has been demonstrated that not only the dimension of the self-assembled nanostructures, but also the packing fashion of the functional naphthalene diimide, a typical n-type chromophore, can be tuned in a noncovalent manner in aqueous solution (see figure).

    2. Organic Magnets

      Pressure-Induced Enhancement of Magnetic-Ordering Temperature in an Organic Radical to 70 K: A Magnetostructural Correlation (pages 8629–8633)

      Richard I. Thomson, Dr. Christopher M. Pask, Dr. Gareth O. Lloyd, Prof. Masaki Mito and Prof. Jeremy M. Rawson

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201200760

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      Squeeze me! The organic magnet p-NCC6F4CNSSN revealed a dramatic increase in the magnetic-ordering temperature under pressure reaching 70 K at 16 kbar. Structure determination from powder X-ray diffraction (PXRD) data coupled with DFT calculations revealed that this is associated with a shortening of the intermolecular S⋅⋅⋅N contacts (see figure).

    3. Supported Catalysts

      A Nano-Fibrillated Mesoporous Carbon as an Effective Support for Palladium Nanoparticles in the Aerobic Oxidation of Alcohols “on Pure Water” (pages 8634–8640)

      Prof. Dr. Babak Karimi, Dr. Hesam Behzadnia, Dr. Mihnea Bostina and Prof. Dr. Hojatollah Vali

      Version of Record online: 15 JUN 2012 | DOI: 10.1002/chem.201200373

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      Chemical aerobics! A new nano-fibrillated mesoporous carbon was successfully prepared by the carbonization of the ionic liquid 1-methyl-3-phenethyl-1H-imidazolium hydrogen sulfate in the presence of SBA-15. The material was shown to be an efficient and highly exciting support for a Pd nanoparticles catalyst in the aerobic oxidation of alcohols on pure water at temperatures as low as 40 °C for the first time.

    4. Vesicles

      Construction of Macroscopic Cytomimetic Vesicle Aggregates Based on Click Chemistry: Controllable Vesicle Fusion and Phase Separation (pages 8641–8646)

      Haibao Jin, Prof. Wei Huang, Yongli Zheng, Yongfeng Zhou and Deyue Yan

      Version of Record online: 8 JUN 2012 | DOI: 10.1002/chem.201201401

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      Making contact: As a mimic of cell–cell aggregation to form tissue, large-scale vesicle aggregates were prepared by using cell-sized hyperbranched polymer vesicles (5–10 μm) as building blocks and click chemistry of a copper-catalysed azide-alkyne cycloaddition reaction as the driving force (see illustration). In addition, lateral phase separations in vesicle membranes and vesicle fusions were performed.

    5. Metallocenes

      Synthesis and Structure of Amido- and Imido(pentafluorophenyl)borane Zirconocene and Hafnocene Complexes: N[BOND]H and B[BOND]H Activation (pages 8647–8658)

      Elizabeth A. Jacobs, Anna Fuller, Simon J. Coles, Garth A. Jones, Graham J. Tizzard, Joseph A. Wright and Simon J. Lancaster

      Version of Record online: 12 JUN 2012 | DOI: 10.1002/chem.201200704

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      Chelate bonding: Lithium amidopentafluorophenylboranes react with electrophilic Group 4 metallocenes through N[BOND]H and B[BOND]H activation to give novel amidoborane and imidoborane complexes, which are bound in chelate fashion with a β-B-agostic interaction (see scheme).

    6. Mesoporous Materials

      Synthesis and Catalytic Properties of Hybrid Mesoporous Materials Assembled from Polyhedral and Bridged Silsesquioxane Monomers (pages 8659–8672)

      Urbano Díaz, Teresa García, Alexandra Velty and Prof. Avelino Corma

      Version of Record online: 8 JUN 2012 | DOI: 10.1002/chem.201200170

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      A bridge too far: Hybrid organic–inorganic mesoporous materials were synthesized by the suitable combination of T8 polyhedral oligomeric (POSS) and arylic-bridged (BTEB) silsesquioxane precursors. The post-synthesis amination treatment has allowed the incorporation of amino groups, generating efficient basic catalysts for C[BOND]C bond-forming reactions (see figure).

    7. Supramolecular Chemistry

      Control of Interpenetration and Gas-Sorption Properties of Metal–Organic Frameworks by a Simple Change in Ligand Design (pages 8673–8680)

      Dr. Thazhe Kootteri Prasad and Prof. Myunghyun Paik Suh

      Version of Record online: 8 JUN 2012 | DOI: 10.1002/chem.201200456

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      Flexible by design: By a slight change in the ligand flexibility, almost-identical frameworks that differ only in their interpenetration were constructed (see figure). The noninterpenetrated framework shows significantly higher gas-sorption capacities at high pressures compared with the interpenetrated structure, which only adsorbs more gas at low pressures (P<1 atm).

    8. Polyoxometalates

      Theoretical Investigation of the Mechanism of Primary Amines Reacting with Hexamolybdate: An Insight into the Organoimido Functionalization and Related Reactions of Polyoxometalates (pages 8681–8691)

      Chunlin Lv, Junjie Hu, Prof. Hong Zhou, Dr. Zhe Li, Rao Naumaan Nasim Khan and Prof. Dr. Yongge Wei

      Version of Record online: 1 JUN 2012 | DOI: 10.1002/chem.201103470

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      Imidoylization mechanism: The mechanism for the formation of organoimido-derivatized hexamolybdates and other related products is investigated using the density functional theory (DFT) method. It is found that dimethylcarbodiimide (DMC) has a catalytic effect on the imidoylization of [Mo6O19]2− (see figure). Furthermore, various factors controlling the efficiency of the imidoylization, including the metal, carbodiimide, and amine as well as the proton, are examined.

    9. Biradical Reactivity

      Reactivity of the 4,5-Didehydroisoquinolinium Cation (pages 8692–8698)

      Dr. Nelson R. Vinueza, Enada F. Archibold, Dr. Bartłomiej J. Jankiewicz, Vanessa A. Gallardo, Dr. Steven C. Habicht, Mohammad Sabir Aqueel, Dr. John J. Nash and Prof. Hilkka I. Kenttämaa

      Version of Record online: 12 JUN 2012 | DOI: 10.1002/chem.201103628

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      The 4,5-didehydroquinolinium cation (1) represents a rare case in which the coupling between the biradical electrons is very weak although the radical sites are in close proximity. These characteristics give this biradical interesting chemical properties. The 4,5-didehydroquinolinium cation was found to exclusively undergo radical reactions, unlike related biradicals with adjacent radical sites.

    10. Fluorescence

      Self-Deprotonation and Colorization of 1,3-Bis(dicyanomethylidene)indan in Polar Media: A Facile Route to a Minimal Polymethine Dye for NIR Fluorescence Imaging (pages 8699–8704)

      Jeongyun Heo, Dr. Chang-Keun Lim, Dong Ryeol Whang, Jiyoung Shin, Prof. Seo Young Jeong, Prof. Soo Young Park, Dr. Ick Chan Kwon and Dr. Sehoon Kim

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201103042

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      Blue is the color: Colorless 1,3-bis(dicyanomethylidene)indan is an organic acid that turns blue in polar media through self-deprotonation. Its colored conjugate base shows potential as a minimal anionic polymethine dye for probing biomolecules in cells and in vivo through noncovalent complexation and near-infrared fluorescence signaling (see figure).

    11. Peptides

      1H-Azepine-4-amino-4-carboxylic Acid: A New α,α-Disubstituted Ornithine Analogue Capable of Inducing Helix Conformations in Short Ala-Aib Pentapeptides (pages 8705–8715)

      Dr. Sara Pellegrino, Dr. Alessandro Contini, Prof. Francesca Clerici, Dr. Alessandro Gori, Donatella Nava and Prof. Maria Luisa Gelmi

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201104023

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      Ahead of the curve: A very efficient synthesis of orthogonally protected 1H-azepine-4-amino-4-carboxylic acid (Azn), a conformationally restricted ornithine analogue, was realized. Azn was used to prepare two pentapeptides (L-Ala-(R/S)-Azn-L-Ala-Aib-L-AlaNH2). Both computational and spectroscopic data (CD/NMR) revealed the capability of (R)-Azn to drive the folding of this short peptide toward a well-defined 310-helix secondary structure (see figure).

    12. Fullerenes and Nanotubes

      A Triptycene-Based Approach to Solubilising Carbon Nanotubes and C60 (pages 8716–8723)

      Peter Hammershøj, Paul H. H. Bomans, Dr. Rajamani Lakshminarayanan, Jeppe Fock, Stig Helmer Jensen, Thomas Sand Jespersen, Theis Brock-Nannestad, Tue Hassenkam, Prof. Jesper Nygård, Prof. Nico A. J. M. Sommerdijk, Prof. Kristine Kilså, Prof. Thomas Bjørnholm and Dr. Jørn Bolstad Christensen

      Version of Record online: 12 JUN 2012 | DOI: 10.1002/chem.201101189

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      Solubilising SWNTs and C60: A triptycene-based surfactant has been designed and synthesised with the ability to solubilise single-walled carbon nanotubes (SWNTs) and C60 in water through non-covalent interactions (see scheme). Absorption spectroscopy, TEM, cryoTEM and AFM were used to study its properties.

    13. Ruthenium Complexes

      New Ruthenium(II) Complexes Functionalized with Coumarin Derivatives: Synthesis, Energy-Transfer-Based Sensing of Esterase, Cytotoxicity, and Imaging Studies (pages 8724–8730)

      Dr. Mei-Jin Li, Dr. Keith Man-Chung Wong, Dr. Changqing Yi and Prof. Vivian Wing-Wah Yam

      Version of Record online: 12 JUN 2012 | DOI: 10.1002/chem.201103025

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      Woodruff—not only tasty! Two new bichromophoric ruthenium(II) complexes with appended coumarin ligands have been synthesized. The energy-transfer-based sensing of esterase by the complexes was studied by using UV/Vis and luminescence spectroscopy. The RuII complex containing a coumarin 343 derivative was found to exhibit only a slight cytotoxicity towards HepG2 cells, and it was easily taken up in the living cells to show evident response to the esterase (see figure).

    14. Asymmetric Synthesis

      Formation of Quaternary Stereogenic Centers by NHC–Cu-Catalyzed Asymmetric Conjugate Addition Reactions with Grignard Reagents on Polyconjugated Cyclic Enones (pages 8731–8747)

      Matthieu Tissot, Daniele Poggiali, Dr. Hélène Hénon, Daniel Müller, Dr. Laure Guénée, Dr. Marc Mauduit and Prof. Alexandre Alexakis

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201200502

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      Along came poly: The copper-catalyzed conjugate addition of Grignard reagents to polyconjugated cyclic enones allows for the formation of all-carbon chiral quaternary centers (see scheme). An N-heterocyclic carbene (NHC) acts as an efficient chiral ligand for this transformation. High enantioselectivities (up to 99 %) and regioselectivities (1,4 selectivity) were obtained for a broad range of substrates and nucleophiles.

    15. Lanthanides

      Paramagnetic 19F Chemical Shift Probes that Respond Selectively to Calcium or Citrate Levels and Signal Ester Hydrolysis (pages 8748–8757)

      Peter Harvey, Dr. Kirsten H. Chalmers, Dr. Elena De Luca, Dr. Anurag Mishra and Prof. David Parker

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201200737

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      A change of scenery: Variations in the coordination environment of paramagnetic lanthanide complexes are signalled by changes in the chemical shift of a reporter CF3 group. Examples include reversible calcium (shown in structure) or citrate binding in the mM range, as well as the irreversible hydrolysis of a remote amide or ester group.

    16. Self-Assembly

      Controlled Self-Assembly by Mono-p-sulfonatocalix[n]arenes and Bis-p-sulfonatocalix[n]arenes (pages 8758–8764)

      Kui Wang, Dr. Dong-Sheng Guo and Prof. Dr. Yu Liu

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201200919

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      Above its critical aggregation concentration, 1-pyrenemethylaminium formed fiber-like aggregates; host–guest complexation in the presence of mono- and bis-p-sulfonatocalix[n]arenes (n=4, 5) led to self-assembly into nanoscale vesicles and rods (see figure).

    17. Iridium Phosphor

      Easy Separation of Δ and Λ Isomers of Highly Luminescent [IrIII]-Cyclometalated Complexes Based on Chiral Phenol-Oxazoline Ancillary Ligands (pages 8765–8773)

      Dr. Enrico Marchi, Dr. Riccardo Sinisi, Dr. Giacomo Bergamini, Dr. Michele Tragni, Prof. Dr. Magda Monari, Prof. Dr. Marco Bandini and Prof. Dr. Paola Ceroni

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201200709

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      Phox and hounds: Δ and Λ isomers of IrIII complexes based on 2-phenyl-pyridyl (ppy) cyclometalating ligands and chiral phenol-oxazoline ancillary ligands (see figure) are readily available through simple separation on an achiral stationary phase. Blue luminescence, combined with an excellent emission quantum yield (Φem=0.80), is recorded for complexes with F2ppy ligands.

    18. Cross-Coupling

      Palladium-Catalysed Cross-Coupling of Vinyldisiloxanes with Benzylic and Allylic Halides and Sulfonates (pages 8774–8779)

      Elizabeth C. Frye, Dr. Cornelius J. O' Connor, David G. Twigg, Bryony Elbert, Luca Laraia, Dr. David G. Hulcoop, Prof. Ashok R. Venkitaraman and Dr. David R. Spring

      Version of Record online: 8 JUN 2012 | DOI: 10.1002/chem.201200431

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      The Hiyama type cross-coupling of aryl and alkyl vinyldisiloxanes with activated alkyl halides and pseudohalides is reported. This methodology is an important expansion of current methods for Csp2–Csp3 bond formation (see scheme). The synthetic utility of the methodology is exemplified in the total synthesis of the natural product bussealin A. In addition, the antiproliferative ability of bussealin A was evaluated in two cancer-cell lines.

    19. Catalysis

      Exploring Between the Extremes: Conversion-Dependent Kinetics of Phosphite-Modified Hydroformylation Catalysis (pages 8780–8794)

      Christoph Kubis, Dr. Detlef Selent, Dr. Mathias Sawall, Prof. Ralf Ludwig, Prof. Klaus Neymeyr, Dr. Wolfgang Baumann, Prof. Robert Franke and Prof. Armin Börner

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201200603

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      Catalyst at work: Organic as well as organometallic components have been followed by FTIR spectroscopy during the rhodium-catalyzed hydroformylation. All concentration profiles obtained fit to Michaelis–Menten-type kinetics. The pre-equilibrium towards the acyl complex intermediate is not established. Spectroscopic and results from DFT calculations show that the coordination mode of the phosphite in the acyl complex is different from that in the corresponding hydride (see figure).

    20. Prebiotic Chemistry

      On the Prebiotic Synthesis of D-Sugars Catalyzed by L-Peptides: Assessments from First-Principles Calculations (pages 8795–8799)

      Dr. David Cantillo, Prof. Martín Ávalos, Prof. Reyes Babiano, Prof. Pedro Cintas, Prof. José L. Jiménez and Prof. Juan C. Palacios

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201200466

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      Sugar daddy: By computing the prebiotic formose reaction with a chiral dipeptide catalyst, the formation of pentoses was mechanistically disentangled. Imine hydrolysis, rather than C[BOND]C bond formation, appears to be the rate-limiting step.

    21. Organic Electrode Materials

      High-Potential Reversible Li Deintercalation in a Substituted Tetrahydroxy-p-benzoquinone Dilithium Salt: An Experimental and Theoretical Study (pages 8800–8812)

      Dr. Anne-Lise Barrès, Dr. Joaquin Geng , Gaëtan Bonnard, Dr. Stéven Renault , Dr. Sébastien Gottis , Dr. Olivier Mentré, Dr. Christine Frayret, Dr. Franck Dolhem and Dr. Philippe Poizot

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201103820

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      A new redox amphoteric system, derived from the tetralithium salt of tetrahydroxy-p-benzoquinone, reversibly deintercalates one Li+ on charging and has a practical capacity of about 100 mAh g−1 at an average potential of 3 V versus Li+/Li0 (see figure). A solvated form of the studied salt (Li2DHDMQ4 H2O) was also characterized by X-ray diffraction and first-principles calculations.

    22. Conformation Analysis

      3-Fluoro-N-methyl-D-aspartic acid (3F-NMDA) Stereoisomers as Conformational Probes for Exploring Agonist Binding at NMDA Receptors (pages 8813–8819)

      Poh Wai Chia, Dr. Matthew R. Livesey, Prof. Dr. Alexandra M. Z. Slawin, Dr. Tanja van Mourik, Prof. Dr. David J. A. Wyllie and Prof. Dr. David O'Hagan

      Version of Record online: 12 JUN 2012 | DOI: 10.1002/chem.201200071

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      Two stereoisomeric analogues of the glutamate receptor agonist N-methyl-D-aspartate (NMDA), display very different activities as a result of the diastereotopic replacement of each of the C-3 hydrogens for fluorine. The difference in agonist activity is attributed to the C[BOND]F bond inducing a different conformational bias in each case. The study illustrates the power of using the C[BOND]F bond to influence the conformation of bioactive amines and explore preferred binding modes to large protein receptors.

    23. Supramolecular Chemistry

      Kinetic Control of the Supramolecular Chirality of Porphyrin J-Aggregates (pages 8820–8826)

      Dr. Alessandro Sorrenti, Dr. Zoubir El-Hachemi, Dr. Oriol Arteaga, Dr. Adolf Canillas, Dr. Joaquim Crusats and Prof. Josep M. Ribo

      Version of Record online: 8 JUN 2012 | DOI: 10.1002/chem.201200881

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      How to avoid the racemic: The aggregation of achiral sulfonatophenyl- and phenyl-meso-substituted diprotonated porphyrins is a noncovalent polymerization process preceded by a critical nucleation stage that yields chiral J-aggregates. Significant enantiomeric excesses are obtained by the formation of a few first nuclei and the control of their growth by the effect of flows (imperfect mixing) on the diffusion of clusters and J-aggregate particles (see figure).

    24. Natural Products

      Marilines A–C: Novel Phthalimidines from the Sponge-Derived Fungus Stachylidium sp. (pages 8827–8834)

      Dr. Celso Almeida, Yasmin Hemberger, Sven Marcel Schmitt, Sarah Bouhired, Lavanya Natesan, Dr. Stefan Kehraus, Dr. Konstantinos Dimas, Prof. Dr. Michael Gütschow, Prof. Dr. Gerhard Bringmann and Prof. Dr. Gabriele M. König

      Version of Record online: 18 JUN 2012 | DOI: 10.1002/chem.201103278

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      Unprecedented phthalimidines inhibition: Marilines A1 and A2 isolated from the marine-derived fungus Stachylidium sp. are potent inhibitors of human leukocyte elastase (HLE) with an IC50 value of 0.86 μM for both enantiomers. The unusual structures of these compounds suggest uncommon biochemical reactions in fungal secondary metabolism. The absolute configurations of the enantiomeric compounds were assigned by a combination of spectroscopic and quantum chemical methods.

    25. Porphyrinoids

      Multiporphyrin Arrays on Cyclophosphazene Scaffolds: Synthesis and Studies (pages 8835–8846)

      Yogita Pareek and Prof. Mangalampalli Ravikanth

      Version of Record online: 11 JUN 2012 | DOI: 10.1002/chem.201200273

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      A series of multiporphyrin and multimetalloporphyrin arrays on cyclotri- and cyclotetraphosphazene scaffolds were synthesized (see figure). These arrays were characterized by means of spectroscopic, photophysical, and electrochemical studies.

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      Preview: Chem. Eur. J. 29/2012 (page 8847)

      Version of Record online: 3 JUL 2012 | DOI: 10.1002/chem.201290119

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