Chemistry - A European Journal

Cover image for Vol. 18 Issue 30

July 23, 2012

Volume 18, Issue 30

Pages 9141–9431

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      Cover Picture: Synthesis of Multifunctional Ag@Au@Phenol Formaldehyde Resin Particles Loaded with Folic Acids for Photothermal Therapy (Chem. Eur. J. 30/2012) (page 9141)

      Ping Yang, Qi-Zhi Xu, Sheng-Yu Jin, Yang Lu, Yang Zhao and Prof. Dr. Shu-Hong Yu

      Version of Record online: 16 JUL 2012 | DOI: 10.1002/chem.201290125

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      Multifunctional Ag@Au@phenol formaldehyde resin (PFR) particles loaded with folic acids (FA) have been designed for killing tumour cells through photothermal conversion under the irradiation of near-infrared light. The multifunctional particles exhibit good fluorescence, low toxicity, and effective targeting for the therapy of tumour cells. Furthermore, the efficiency of photothermal therapy (PTT) and fluorescence intensity can be tuned by simply changing the added amount of HAuCl4. For more details, see the Full Paper by S.-H. Yu et al. on page 9294 ff.

  2. Inside Cover

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    1. Inside Cover: Cucurbit[7]uril Pseudorotaxane-Based Photoresponsive Supramolecular Nanovalve (Chem. Eur. J. 30/2012) (page 9142)

      Yu-Long Sun, Dr. Bing-Jie Yang, Dr. Sean Xiao-An Zhang and Prof. Ying-Wei Yang

      Version of Record online: 16 JUL 2012 | DOI: 10.1002/chem.201290126

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      Dethreading of Cucurbit[7]uril CB[7]-based photoresponsive nanovalves utilizing biocompatible components that operate in water and biological media have been successfully constructed. The nanovalves employed tunable binding interactions between CB[7] rings and the cinnamamide stalks installed on the outer rim of mesoporous silica nanoparticles, and can be operated easily and effectively by irradiation with light (λ=300 nm), which induces a trans- to cis-conformational change of the cinnamamide stalks leading to the dethreading of CB[7]. For more details, see the Full Paper by Y.-W. Yang et al on page 9212 ff.

  3. Graphical Abstract

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  4. News

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  5. Minireview

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    1. Natural Products

      ortho-Quinone Methides in Natural Product Synthesis (pages 9160–9173)

      Nicky J. Willis and Dr. Christopher D. Bray

      Version of Record online: 15 JUN 2012 | DOI: 10.1002/chem.201200619

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      Orchestrating reactions: ortho-Quinone methides (o-QMs) are highly labile, often transient species, the inherent reactivity of which can be used for orchestrating linchpin reactions in total synthesis. A review of their use in natural product syntheses is presented.

  6. Communications

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    1. Polyoxometalates

      Polyoxometalate–Organic Hybrid Molecules as Amphiphilic Emulsion Catalysts for Deep Desulfurization (pages 9174–9178)

      Panchao Yin, Joy Wang, Dr. Zicheng Xiao, Pingfan Wu, Prof. Dr. Yongge Wei and Prof. Dr. Tianbo Liu

      Version of Record online: 22 JUN 2012 | DOI: 10.1002/chem.201201551

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      So emulsional: Two hexavanadate–organic hybrids were synthesized and their amphiphilic properties were confirmed by forming emulsions in mixtures of water and nonpolar organic solvents, and were utilized as “emulsion catalysts” in deep desulfurization reactions (see figure). Their catalytic activities show a pH-dependent behavior, which can be explained by the size-change of emulsions and the appearance of reverse emulsions.

    2. Selenium

      X-ray Absorption Spectroscopic, Crystallographic, Theoretical (DFT) and Chemical Evidence for a Chalcogen–Chalcogen Two-Center/Three-Electron Half Bond in an Unprecedented “Subselenide” Se23− Ligand (pages 9179–9183)

      Dr. Shu A. Yao, Prof. Kyle M. Lancaster, Dr. Andreas W. Götz, Prof. Serena DeBeer and Prof. John F. Berry

      Version of Record online: 21 JUN 2012 | DOI: 10.1002/chem.201201291

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      Doing things by halves: The dimeric compound (Cp′Ni)22-Se2) (Cp′=1,2,3,4-tetraisopropylcyclopentadienyl), shown in the scheme, was investigated by using low temperature X-ray crystallography and X-ray absorption spectroscopy. The Se K-edge energy strongly indicates a Se physical oxidation state of −1.5, consistent with an unprecedented two-center/three-electron half-bonded Se23− or “subselenide” ion.

    3. Polyoxometalates

      Inorganic Crown Ethers: Sulfate-Based Preyssler Polyoxometalates (pages 9184–9188)

      Dr. Zhi-Ming Zhang, Dr. Shuang Yao, Dr. Yang-Guang Li, Xin-Bao Han, Prof. Zhong-Min Su, Zhi-Shu Wang and Prof. En-Bo Wang

      Version of Record online: 26 JUN 2012 | DOI: 10.1002/chem.201200555

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      A tungsten crown: The {SO4} units were introduced into the {W30} crown, resulting in a new Preyssler polyoxoanion {S5W30} with position-specific, guest, K+ or Na+ ions in its geometrical center. The as-prepared polyoxoanion exhibits an interesting ion-selective encapsulation of K+ and Na+ (see figure).

    4. Metal–Metal Bonds

      A Theoretical Revisit to the Lowest Ionization Potentials in Metal–Metal Bonds (pages 9189–9193)

      Dr. I-Ya Chang and Prof. Dr. Jen-Shiang K. Yu

      Version of Record online: 20 JUN 2012 | DOI: 10.1002/chem.201200731

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      The ties that bind: The electrostatic potential of quadruply bonded W2(hpp)4 and its cation support the idea that the very low ionization energies are due to excitations from the metal–metal bonding core. Theoretical MRCI computations based on CASSCF orbitals show that the relativistic effect influences the lowest four ionization energies, leading to distinct IE sequences: IEδ < IEπ < IEσ in W2(hpp)4, and IEδ < IEσ < IEπ in Mo2(hpp)4.

    5. C[BOND]C Activation

      A New Mode of Activation of CO2 by Metal–Ligand Cooperation with Reversible C[BOND]C and M[BOND]O Bond Formation at Ambient Temperature (pages 9194–9197)

      Dr. Matthias Vogt, Moti Gargir, Dr. Mark A. Iron, Dr. Yael Diskin-Posner, Yehoshoa Ben-David and Prof. Dr. David Milstein

      Version of Record online: 26 JUN 2012 | DOI: 10.1002/chem.201201730

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      Team work: Although CO2 binding to metal centers usually involves π coordination to a C[DOUBLE BOND]O group or σ bonds to the carbon or oxygen atom of the CO2 molecule, a new mode of metal–ligand cooperative activation of CO2 to a ruthenium PNP pincer complex involving aromatization/dearomatization steps is presented in experimental and theoretical studies (see scheme).

    6. Heterocyclic Carbenes

      N-Heterocyclic Carbene-Catalyzed Homoenolate Additions with N-Aryl Ketimines as Electrophiles: Efficient Synthesis of Spirocyclic γ-Lactam Oxindoles (pages 9198–9203)

      Bo Zhang, Peng Feng, Li-Hui Sun, Dr. Yuxin Cui, Dr. Song Ye and Dr. Ning Jiao

      Version of Record online: 26 JUN 2012 | DOI: 10.1002/chem.201201375

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      In pole position: A simple and efficient approach to spirocyclic γ-lactam oxindoles by the N-heterocyclic carbene catalyzed addition of homoenloate equivalents to N-aryl isatinimines has been developed (see scheme). The use of N-aryl isatinimines as electrophiles in the NHC-catalyzed umpolung reaction of α,β-unsaturated aldehydes is demonstrated for the first time.

    7. Organocatalysis

      Highly Enantioselective Reduction of β-Amino Nitroolefins with a Simple N-Sulfinyl Urea as Bifunctional Catalyst (pages 9204–9207)

      Xiang-Wei Liu, Yan Yan, Yong-Qiang Wang, Chao Wang and Prof. Dr. Jian Sun

      Version of Record online: 26 JUN 2012 | DOI: 10.1002/chem.201201192

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      Simple but effective: A structurally simple N-sulfinyl urea was found to be a highly efficient bifunctional catalyst, which allows for the development of a novel pathway for the construction of chiral β-amino nitroalkanes through enantioselective reduction of β-amino nitroolefins by trichlorosilane. High yields and excellent enantioselectivities were obtained for a broad range of β-arylamino nitroolefin substrates (see scheme).

    8. Asymmetric Catalysis

      Highly Enantioselective Addition of 1,3-Diynes to Aldehydes Catalyzed by a Zinc–Amino Alcohol Complex (pages 9208–9211)

      Bing Zheng, Shuo-Ning Li, Jian-You Mao, Bo Wang, Dr. Qing-Hua Bian, Dr. Shang-Zhong Liu, Dr. Jiang-Chun Zhong, Dr. Hong-Chao Guo and Dr. Min Wang

      Version of Record online: 19 JUN 2012 | DOI: 10.1002/chem.201200728

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      Asymmetric catalysis: A highly enantioselective and efficient procedure for the amino alcohol–zinc-catalyzed addition of 1,3-diynes to various aromatic, α,β-unsaturated, and aliphatic aldehydes has been developed. The present catalytic system was successfully applied in the concise synthesis of natural products such as (S)-strongylodiols A and B (see scheme).

    9. Supramolecular Chemistry

      Cucurbit[7]uril Pseudorotaxane-Based Photoresponsive Supramolecular Nanovalve (pages 9212–9216)

      Yu-Long Sun, Dr. Bing-Jie Yang, Dr. Sean Xiao-An Zhang and Prof. Ying-Wei Yang

      Version of Record online: 20 JUN 2012 | DOI: 10.1002/chem.201201083

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      Light relief! Mesoporous silica materials equipped with photoresponsive cucurbit[7]uril-pseudorotaxane nanovalves operate in biological media to trap cargo molecules within nanopores, but undergo controlled release when irradiated with light of a suitable wavelength (see figure). Significantly, a “ladder”-release pattern is obtained to balance maximal therapeutic efficacy and minimal dose frequency in the development of “pulsed” drug therapy.

    10. Organic Methodology

      Catalyst- and Halogen-Free Regioselective Friedel–Crafts α-Ketoacylations (pages 9217–9220)

      Dr. Kishor Mohanan, Dr. Marc Presset, Dr. Damien Mailhol, Dr. Yoann Coquerel and Prof. Dr. Jean Rodriguez

      Version of Record online: 22 JUN 2012 | DOI: 10.1002/chem.201201027

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      Fast, efficient and green! Highly regioselective and efficient catalyst- and halogen-free Friedel–Crafts α-ketoacylation reactions leading to heterocycles functionalized with a very versatile 1,3-diketone moiety are described. The reactions rely on microwave-assisted domino Wolff rearrangement/Friedel–Crafts sequences from 2-diazo-1,3-diketones via transient, highly reactive α-keto ketene intermediates.

    11. Synthetic Methods

      Copper(I)-Catalyzed [3+1] Cycloaddition of Alkenyldiazoacetates and Iminoiodinanes: Easy Access to Substituted 2-Azetines (pages 9221–9224)

      Prof. José Barluenga, Dr. Lorena Riesgo, Giacomo Lonzi, Prof. Miguel Tomás and Dr. Luis A. López

      Version of Record online: 21 JUN 2012 | DOI: 10.1002/chem.201200998

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      The copper(I)-catalyzed reaction of alkenyldiazoacetates and iminoiodinanes affords functionalized azetine derivatives. This process is consistent with the formation of an aziridinyldiazoacetate intermediate, which gives rise to the four-membered heterocycles by metal-catalyzed ring expansion. The resulting azetine structure is a direct precursor of azeditine-2-carboxylic acid derivatives (EWG=electron-withdrawing group).

    12. Asymmetric Catalysis

      Rhodium-Catalyzed Linear Cross-Trimerization of Two Different Alkynes with an Alkene and Two Different Alkenes with an Alkyne (pages 9225–9229)

      Masayuki Kobayashi and Prof. Dr. Ken Tanaka

      Version of Record online: 22 JUN 2012 | DOI: 10.1002/chem.201200903

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      Crossing paths with rhodium: A cationic RhI/H8-BINAP complex has been found to catalyze the linear cross-trimerization of terminal alkynes, acetylenedicarboxylates, and acrylamides to give substituted trienes. The asymmetric linear cross-trimerization, giving substituted chiral dienes, has also been achieved by using monosubstituted alkenes and (R)-BINAP instead of terminal alkynes and H8-BINAP (see scheme; H8-BINAP=2,2′-bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl; BINAP=2,2′-bis(diphenylphosphino)-1,1′-binaphthyl]).

  7. Full Papers

    1. Top of page
    2. Cover Picture
    3. Inside Cover
    4. Graphical Abstract
    5. News
    6. Minireview
    7. Communications
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    1. Quantum Dots

      Large-Scale Synthesis of High-Quality Metal Sulfide Semiconductor Quantum Dots with Tunable Surface-Plasmon Resonance Frequencies (pages 9230–9238)

      Dr. Masayuki Kanehara, Hisamitsu Arakawa, Tetsuya Honda, Dr. Masaki Saruyama and Dr. Toshiharu Teranishi

      Version of Record online: 25 JUN 2012 | DOI: 10.1002/chem.201201159

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      Size-dependent surface-plasmon resonance: A new method to synthesize high-quality CdS and Cu7S4 quantum dots (QDs) by using N,N-dibutylthiourea (DBTU) as a sulfur source was developed. As observed in noble metal nanostructures, the larger-sized anisotropic disk-shaped Cu7S4 QDs exhibited lower NIR LSPR energy (see figure).

    2. Imaging Agents

      Enhanced Red Emission from GdF3:Yb3+,Er3+ Upconversion Nanocrystals by Li+ Doping and Their Application for Bioimaging (pages 9239–9245)

      Wenyan Yin, Dr. Lina Zhao, Liangjun Zhou , Dr. Zhanjun Gu, Xiaoxiao Liu, Gan Tian , Shan Jin , Liang Yan, Wenlu Ren, Prof. Gengmei Xing and Prof. Yuliang Zhao 

      Version of Record online: 22 JUN 2012 | DOI: 10.1002/chem.201201053

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      Dual-modality biolabels: GdF3:Yb,Er upconversion nanoparticles (UCNPs) can be tuned in emission color from yellow to increasingly red by doping with Li+ ions (see figure). The red emission of silica-coated GdF3:Yb,Er,Li UCNPs has great potential for in vivo and in vitro optical imaging, while the positive-contrast effect of their Gd3+ ions allows them to be used in magnetic resonance imaging.

    3. Drug Design

      From lin-Benzoguanines to lin-Benzohypoxanthines as Ligands for Zymomonas mobilis tRNA–Guanine Transglycosylase: Replacement of Protein–Ligand Hydrogen Bonding by Importing Water Clusters (pages 9246–9257)

      Luzi Jakob Barandun, Florian Immekus, Dr. Philipp C. Kohler, Sandro Tonazzi, Björn Wagner, Severin Wendelspiess, Dr. Tina Ritschel, Dr. Andreas Heine, Dr. Manfred Kansy, Prof. Dr. Gerhard Klebe and Prof. Dr. François Diederich

      Version of Record online: 26 JUN 2012 | DOI: 10.1002/chem.201200809

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      Water replacements: A series of lin-benzopurines was evaluated as inhibitors of Zymomonas mobilis tRNA–guanine transglycosylase, an enzyme that was identified as a potential target for the treatment of shigellosis. X-ray cocrystal structures show the import of a new water cluster that replaces lost protein–ligand interactions (see figure), with an overall reduction in binding affinity.

    4. Dyes

      Octupolar Merocyanine Dyes: A New Class of Nonlinear Optical Chromophores (pages 9258–9266)

      Dr. Yevgen M. Poronik, Vincent Hugues, Dr. Mireille Blanchard-Desce and Prof. Dr. Daniel T. Gryko

      Version of Record online: 21 JUN 2012 | DOI: 10.1002/chem.201200718

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      Octupolar merocyanine chromophores displayed very high molar absorption coefficients and high two-photon absorption cross-sections in the spectral range of interest for biological imaging. Changing the end heterocyclic moieties allowed the tuning of optical properties to approach the cyanine limit (i.e., polymethine state); this resulted in a red-shift of the linear absorption band, as well as in the rise of a two-photon band in the NIR region.

    5. Ligand Effects

      Theoretical Insights into the Mechanism of Carbon Monoxide (CO) Release from CO-Releasing Molecules (pages 9267–9275)

      Dr. Sai Vikrama Chaitanya Vummaleti, Dr. Davide Branduardi, Dr. Matteo Masetti, Dr. Marco De Vivo, Prof. Roberto Motterlini and Prof. Andrea Cavalli

      Version of Record online: 22 JUN 2012 | DOI: 10.1002/chem.201103617

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      How do CO-releasing molecules release CO? The DFT inspection of manganese-containing carbon-monoxide-releasing molecules (CO-RMs) leads to the discrimination of good CO releasers from bad ones. Natural bond orbital analysis of the Mn[BOND]CO bond reveals that the charge transfer is the major source of stabilization (see figure).

    6. Organocatalysis

      Enantioselective Synthesis of AG-041R by using N-Heteroarenesulfonyl Cinchona Alkaloid Amides as Organocatalysts (pages 9276–9280)

      Noriyuki Hara, Prof. Shuichi Nakamura, Masahide Sano, Ryota Tamura, Prof. Yasuhiro Funahashi and Prof. Norio Shibata

      Version of Record online: 26 JUN 2012 | DOI: 10.1002/chem.201200367

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      Enantioselective catalysis: The organocatalytic enantioselective decarboxylative addition of malonic acid half thioesters to ketimines affords products with high enantioselectivities (see scheme; CPME=cyclopentyl methyl ether). The products can be converted into optically active AG-041R. Hydrogen bonding plays an important role in the enantioselectivity of the reaction.

    7. Magnetochemistry

      Structure and Magnetic Ordering of the Anomalous Layered (2D) Ferrimagnet [NEt4]2MnII3(CN)8 and 3D Bridged-Layered Antiferromagnet [NEt4]MnII3(CN)7 Prussian Blue Analogues (pages 9281–9288)

      Christopher M. Kareis, Dr. Jae-Hyuk Her, Prof. Peter W. Stephens, Dr. Joshua G. Moore and Prof. Joel S. Miller

      Version of Record online: 19 JUN 2012 | DOI: 10.1002/chem.201200672

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      Prussian virtues: The reaction of [NEt4]CN and Mn(O2CMe)2 unexpectedly formed [NEt4]MnII3(CN)7 and [NEt4]2MnII3(CN)8 solvated materials; these are distinctly different to previously characterized members of the Prussian blue family. These unexpected stoichiometries, layered and bridged-layered structures (see figure), as well as their magnetic ordering, are reported herein.

    8. Fullerenes

      Capturing the Antiaromatic #6094C68 Carbon Cage in the Radio-Frequency Furnace (pages 9289–9293)

      Dr. Konstantin Yu. Amsharov, Karolin Ziegler, Andreas Mueller and Prof. Martin Jansen

      Version of Record online: 26 JUN 2012 | DOI: 10.1002/chem.201200894

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      Antiaromatic fullerene: The existence of antiaromatic carbon cages has been experimentally confirmed by capturing the highly antiaromatic #6094C68 through in situ chlorination. The structure of the resulting chlorinated derivative C68Cl8 was unambiguously determined by single-crystal X-ray analysis. (see figure).

    9. Nanoparticles

      Synthesis of Multifunctional Ag@Au@Phenol Formaldehyde Resin Particles Loaded with Folic Acids for Photothermal Therapy (pages 9294–9299)

      Ping Yang, Qi-Zhi Xu, Sheng-Yu Jin, Yang Lu, Yang Zhao and Prof. Dr. Shu-Hong Yu

      Version of Record online: 28 JUN 2012 | DOI: 10.1002/chem.201201173

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      Locked and loaded: Multifunctional particles composed of an Ag core, an Au layer, and a phenol formaldehyde resin (PFR) shell were synthesized by a hydrothermal process with good reproducibility. Attachment of folic acids onto the PFR shell results in photothermal conversion particles, which exhibit high fluorescence, low toxicity, and effective targeting for the therapy of tumor cells (see figure).

    10. DNA

      Molecular Arrangement and Assembly Guided by Hydrophobic Cavities inside DNA (pages 9300–9304)

      Dr. Tadao Takada, Yumiko Otsuka, Dr. Mitsunobu Nakamura and Prof. Dr. Kazushige Yamana

      Version of Record online: 19 JUN 2012 | DOI: 10.1002/chem.201201469

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      Filling the gaps: Molecular arrangement and assembly within π-stacked arrays of DNA were achieved by utilizing artificial hydrophobic cavities to accommodate ligand molecules (perylenediimide (PDI); see scheme). Site-specific binding of PDI to the cavity, formation of stacked PDI molecules in the cavity, and binding of two PDIs to different binding cavities were characterized by monitoring spectroscopic characteristics of the PDI molecules.

    11. Nanostructures

      Controlled Synthesis of Carbon-Encapsulated Copper Nanostructures by Using Smectite Clays as Nanotemplates (pages 9305–9311)

      Dr. Theodoros Tsoufis, Dr. Jean-François Colomer, Dr. Enrico Maccallini, Dr. Lubos Jankovič, Prof. Dr. Petra Rudolf and Prof. Dr. Dimitrios Gournis

      Version of Record online: 20 JUN 2012 | DOI: 10.1002/chem.201103899

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      Differently shaped Cu nanostructures were encapsulated within graphite shells by using a simple chemical method that involved the catalytic decomposition of acetylene over Cu catalysts that were supported on different smectite clay surfaces. The Cu nanostructures could be separated from the support and remained stable for months. The choice of clay support influenced the shape and size of the Cu nanostructures.

    12. Hydroboration

      Inherent Stability Limits of Intramolecular Boron Nitrogen Lewis Acid–Base Pairs (pages 9312–9320)

      Daniel Winkelhaus, Beate Neumann, Dr. Hans-Georg Stammler, Dr. Raphael J. F. Berger, Dr. Yuri V. Vishnevskiy and Prof. Dr. Norbert W. Mitzel

      Version of Record online: 15 JUN 2012 | DOI: 10.1002/chem.201200442

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      Two roads diverged: Two different reaction pathways in the hydroboration of allylamines R2NCH2CHCH2 with (C6F5)2BH lead to the expected heterocycles with B[BOND]N bonds for small R substituents, but to hydride abstraction and evolution of dihydrogen for R=iPr (see scheme).

    13. Biomolecule Fragmentation

      A Multicoincidence Study of Fragmentation Dynamics in Collision of γ-Aminobutyric Acid with Low-Energy Ions (pages 9321–9332)

      Dr. Michael Capron, Dr. Sergio Díaz-Tendero, Sylvain Maclot, Dr. Alicja Domaracka, Elie Lattouf, Dr. Arkadiusz Ławicki, Dr. Rémi Maisonny, Prof. Jean-Yves Chesnel, Dr. Alain Méry, Dr. Jean-Christophe Poully, Dr. Jimmy Rangama, Prof. Lamri Adoui, Prof. Fernando Martín, Prof. Manuel Alcamí, Dr. Patrick Rousseau and Prof. Bernd A. Huber

      Version of Record online: 25 JUN 2012 | DOI: 10.1002/chem.201103922

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      Pure coincidence? A combination of mass spectrometric experiments with multicoincidence detection and quantum chemical calculations has been used to unravel the fragmentation mechanisms of the neuroinhibitor γ-aminobutyric acid in the gas phase. Singly charged cyclic structures play an important role in the fragmentation, which preferentially takes place at the Cβ[BOND]Cγ bond (see figure).

    14. Acidity

      Bulk Gas-Phase Acidity (pages 9333–9340)

      Dr. Daniel Himmel, Dipl.-Chem. Sascha K. Goll, Prof. Dr. Ivo Leito and Prof. Dr. Ingo Krossing

      Version of Record online: 21 JUN 2012 | DOI: 10.1002/chem.201104025

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      Brønsted “gacids”: Brønsted acidity in the gas phase has been systematically extended from the established gas-phase acidity values to the pressure-dependent bulk acidity. Analogies to protolysis in solution are illustrated on the basis of a unified pHabs scale. For most gaseous acids, the pressure-dependent speciation of ions in the gas phase must be considered (see figure) to obtain meaningful thermodynamic acidities of bulk gases.

    15. Enzyme Inhibitors

      Scalable Syntheses of Both Enantiomers of DNJNAc and DGJNAc from Glucuronolactone: The Effect of N-Alkylation on Hexosaminidase Inhibition (pages 9341–9359)

      Andreas F. G. Glawar, Dr. Daniel Best, Benjamin J. Ayers, Saori Miyauchi, Shinpei Nakagawa, Matilde Aguilar-Moncayo, Prof. José M. García Fernández, Prof. Carmen Ortiz Mellet, Dr. Elizabeth V. Crabtree, Dr. Terry D. Butters, Dr. Francis X. Wilson, Prof. Atsushi Kato and Prof. George W. J. Fleet

      Version of Record online: 26 JUN 2012 | DOI: 10.1002/chem.201200110

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      Getting the NAc of it: Scalable syntheses of DGJNAc and DNJNAc from D-glucuronolactone are reported. DGJNAc and its N-alkyl derivatives were inhibitors of α-GalNAcase and both DGJNAc and DNJNAc were potent inhibitors of β-GlcNAcases and β-GalNAcases.

    16. Dual ROP Catalysts

      Discrete Cationic Zinc and Magnesium Complexes for Dual Organic/Organometallic-Catalyzed Ring-Opening Polymerization of Trimethylene Carbonate (pages 9360–9370)

      Dr. Pierre Brignou, Dr. Sophie M. Guillaume, Dr. Thierry Roisnel, Dr. Didier Bourissou and Prof. Jean-François Carpentier

      Version of Record online: 26 JUN 2012 | DOI: 10.1002/chem.201200336

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      It takes two! The combination of a Lewis acidic cationic metal fragment, to activate the monomer, and a tertiary amine, to enhance the nucleophilicity of the protic initiator, generates a highly active catalytic system for the controlled ring-opening polymerization of trimethylene carbonate (see scheme). The role of each component of this original dual-catalyst system has been scrutinized.

    17. Superacids

      Synthesis, Characterization, and Application of Two Al(ORF)3 Lewis Superacids (pages 9371–9380)

      Dipl.-Chem. Anne Kraft, Dr. Nils Trapp, Dr. Daniel Himmel, Dipl.-Chem. Hannes Böhrer, Dipl.-Chem. Peter Schlüter, Dr. Harald Scherer and Prof. Dr. Ingo Krossing

      Version of Record online: 26 JUN 2012 | DOI: 10.1002/chem.201200448

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      A super method! The synthesis of the donor-free Lewis superacids Al(ORF)3 with ORF=OC(CF3)3 (1) and OC(C5F10)C6F5 (2), as well as stabilization of 1 with the very weak Lewis bases PhF, 1,2-F2C6H4, and SO2, is reported (see figure). Applications of 1 and 2 in bond heterolysis reactions with Cl[BOND]CPh3 giving the trityl cation and the respective weakly coordinating anion [ClAl(ORF)3] are also described.

    18. Nanostructures

      Controlled Synthesis of Gold Nanostars by Using a Zwitterionic Surfactant (pages 9381–9390)

      Dr. Alberto Casu, Dr. Elisa Cabrini, Dr. Alice Donà, Dr. Andrea Falqui, Dr. Yuri Diaz-Fernandez, Dr. Chiara Milanese, Prof. Angelo Taglietti and Prof. Piersandro Pallavicini

      Version of Record online: 26 JUN 2012 | DOI: 10.1002/chem.201201024

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      Stargazing: Laurylsulfobetaine (LSB), a zwitterionic surfactant, was introduced into the seed-growth approach for the synthesis of gold nano-objects. Nanostars were obtained. The aspect ratio of their branches could be easily tuned by multiple synthetic parameters, which finely regulated the localized surface plasmon resonance absorption in the near-IR region (see figure). Removal of LSB led to stable nanostars under all conditions.

    19. Benzyl Carbanions

      Beyond Benzyl Grignards: Facile Generation of Benzyl Carbanions from Styrenes (pages 9391–9396)

      R. David Grigg, Jared W. Rigoli, Ryan Van Hoveln, Samuel Neale and Prof. Jennifer M. Schomaker

      Version of Record online: 20 JUN 2012 | DOI: 10.1002/chem.201200642

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      Make or break: The facile generation of benzyl anion equivalents from styrenes has been achieved by using a Cu-catalyzed hydroboration in conjunction with sterically induced cleavage of the C[BOND]B bond with tBuOK. Quenching this reactive intermediate with heteroallene electrophiles yields benzylic C[BOND]C bond formation (see scheme), and the utility of this methodology has been demonstrated by a synthesis of the nonsteroidal anti-inflammatory drug (±)-flurbiprofen.

    20. Isotopes

      Highly Efficient D2 Generation by Dehydrogenation of Formic Acid in D2O through H+/D+ Exchange on an Iridium Catalyst: Application to the Synthesis of Deuterated Compounds by Transfer Deuterogenation (pages 9397–9404)

      Dr. Wan-Hui Wang, Dr. Jonathan F. Hull, Dr. James T. Muckerman, Dr. Etsuko Fujita, Prof. Dr. Takuji Hirose and Dr. Yuichiro Himeda

      Version of Record online: 20 JUN 2012 | DOI: 10.1002/chem.201200576

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      Cheap D2 gas! Convenient generation of deuterium gas (D2) and preparation of deuterated compounds on a laboratory scale are demonstrated using a half-sandwich iridium complex with 4,4′-dihydroxy-2,2′-bipyridine (see scheme). The “umpolung” of a hydrogen atom of water was achieved in consecutive reactions (cationic H+/D+ exchange reaction and anionic hydride (deuteride) transfer) under mild conditions.

    21. Molecular Dynamics

      Ensemble-Averaged QM/MM Kinetic Isotope Effects for the SN2 Reaction of Cyanide Anions with Chloroethane in DMSO Solution (pages 9405–9414)

      Dr.  J. Javier Ruiz Pernía and Prof. Ian H. Williams

      Version of Record online: 26 JUN 2012 | DOI: 10.1002/chem.201200443

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      Better on average! Average AM1/OPLS-AA kinetic isotope effects (KIEs) computed for NC+EtCl in DMSO agree with experiment for isotopic substitutions in six positions, and their distributions for individual configurations provide insight into solvent fluctuation effects. A single-molecule view of chemical change should be replaced by a picture involving averages over representative collections of molecules (see figure).

    22. Carbonylation

      Pd/Light-Accelerated Atom-Transfer Carbonylation of Alkyl Iodides: Applications in Multicomponent Coupling Processes Leading to Functionalized Carboxylic Acid Derivatives (pages 9415–9422)

      Dr. Akira Fusano, Shuhei Sumino, Satoshi Nishitani, Takaya Inouye, Keisuke Morimoto, Dr. Takahide Fukuyama and Prof. Ilhyong Ryu

      Version of Record online: 25 JUN 2012 | DOI: 10.1002/chem.201200752

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      Light, camera, ATCion: Atom-transfer carbonylation of alkyl iodides to afford carboxylic acid esters was accelerated by the addition of transition-metal catalysts under photoirradiation. The carbonylation step proceeded through a radical mechanism.

    23. Core–Shell Nanostructures

      A General and High-Yield Galvanic Displacement Approach to Au[BOND]M (M=Au, Pd, and Pt) Core–Shell Nanostructures with Porous Shells and Enhanced Electrocatalytic Performances (pages 9423–9429)

      Long Kuai, Prof. Dr. Baoyou Geng, Shaozhen Wang and Yan Sang

      Version of Record online: 19 JUN 2012 | DOI: 10.1002/chem.201200893

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      Galvanic displacement synthesis has been employed as a general and efficient method for the preparation of core–shell nanostructures with porous shells. The method is generally applicable to the preparation of Au[BOND]Au, Au[BOND]Pd, and Au[BOND]Pt porous core–shell nanostructures (see figure). The lower oxidation states of AuI, PdII, and PtII contribute to the formation of the porous core–shell nanostructures.

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      Preview: Chem. Eur. J. 31/2012 (page 9431)

      Version of Record online: 16 JUL 2012 | DOI: 10.1002/chem.201290129

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