Chemistry - A European Journal

Cover image for Vol. 19 Issue 2

January 7, 2013

Volume 19, Issue 2

Pages 417–792

  1. Cover Pictures

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    1. You have free access to this content
      Cover Picture: Structure-Dependent Electrocatalysis of Ni(OH)2 Hourglass-like Nanostructures Towards L-Histidine (Chem. Eur. J. 2/2013) (page 417)

      Dr. Jianwei Nai, Zhengbo Chen, Haopeng Li, Fangyuan Li, Yang Bai, Prof. Lidong Li and Lin Guo

      Article first published online: 2 JAN 2013 | DOI: 10.1002/chem.201390000

      Thumbnail image of graphical abstract

      Hourglass-like Ni(OH)2 nanostructures were selected to serve as electrode modifiers to demonstrate the correlation between the structure of nanomaterials and their electrocatalytic activity on L-histidine. All three types of Ni(OH)2 nanostructure-modified electrodes have a lower detection limit and wider linear range than the commercial materials. The electrocatalytic activity of these unique nanostructures was found to not only depend on their external architecture, but also on their relevant internal degree of crystallinity. These findings may enable the design of new and better electrocatalytic materials by using shape-controlled nanoparticles. For more details see the Full Paper by Li and Guo et al. on page 501 ff.

    2. You have free access to this content
      Back Cover: Improvement of the Visible-Light Photocatalytic Performance of TiO2 by Carbon Mesostructures (Chem. Eur. J. 2/2013) (page 796)

      Wei Wei, Dr. Chao Yu, Qingfei Zhao, Prof. Guisheng Li and Prof. Ying Wan

      Article first published online: 2 JAN 2013 | DOI: 10.1002/chem.201390003

      Thumbnail image of graphical abstract

      Cleaning earth by using a mesoporous C-TiO2 catalyst and sunshine! The mesoporous carbon-titania composite is proved to show excellent adsorption–catalysis cycles in the elimination of azo dyes. The mesostructure, which includes mesopores, carbon pore walls and carbon doping anatase nanoparticles (formed by interaction between carbon and titania and immobilized inside framework), is responsible for the improved photocatalytic performance and reusability as described in the Full Paper by Y. Wan et al. on page 566 ff.

  2. Graphical Abstract

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

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

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

      Self-Assembled Vesicles with Functionalized Membranes (pages 438–448)

      Dr. Benjamin Gruber and Prof. Dr. Burkhard König

      Article first published online: 23 NOV 2012 | DOI: 10.1002/chem.201202982

      Thumbnail image of graphical abstract

      Breaking the surface: The embedding of amphiphilic binding sites, dyes, or catalysts into vesicular bilayer membranes provides rapid and simple access to soft functional surfaces (see figure). The dynamic organization of these self-assembled nanosystems enables a number of interesting applications, such as biomolecule sensing and catalytic transformations at interfaces.

  5. Communications

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    1. N-Heterocyclic Carbenes

      Anionic N-Heterocyclic Carbene Ligands from Mesoionic Imidazolium Precursors: Remote Backbone Arylimino Substitution Directs Carbene Coordination (pages 450–455)

      Prof. Dr. Andreas A. Danopoulos, Dr. Kirill Yu. Monakhov and Prof. Dr. Pierre Braunstein

      Article first published online: 23 DEC 2012 | DOI: 10.1002/chem.201203488

      Thumbnail image of graphical abstract

      Versatile precursor to metal complexes: The lithiated N-heterocyclic carbene derivative [Li(imino–imidide)(tmeda)] (imino–imidide=4-(2,6-diisopropylphenylimino)imidazol-2-ylidenide), obtained by deprotonation and lithiation of a mesoionic 4-aryliminoimidazolium, serves as a versatile precursor to metal complexes with the anionic 4-aryliminoimidazolide by salt metathesis. DFT calculations demonstrate that tuneable electronic and steric factors of the substituent at the Nexo imino function of the heterocycle dictate the preferred site of the metallation (CNHC vs. Nexo).

    2. Annulation

      N-Heterocyclic-Carbene-Catalyzed Reaction of α-Bromo-α,β-Unsaturated Aldehyde or α,β-Dibromoaldehyde with Isatins: An Efficient Synthesis of Spirocyclic Oxindole–Dihydropyranones (pages 456–459)

      Prof. Dr. Changsheng Yao, Zhaoxin Xiao, Rui Liu, Prof. Dr. Tuanjie Li, Weihui Jiao and Prof. Chenxia Yu

      Article first published online: 7 DEC 2012 | DOI: 10.1002/chem.201202655

      Thumbnail image of graphical abstract

      Smooth as isatin! A straightforward synthesis of spirocyclic oxindole–dihydropyranones through an N-heterocyclic-carbene-catalyzed [4+2] annulation of α-bromo-α,β-unsaturated aldehydes or α,β-dibromoaldehyde bearing γ-H with isatin derivatives under mild reaction conditions is disclosed (see scheme). The concise construction, ready availability of the starting materials, avoidance of external oxidants, and the potential utilization value of final products in molecular biology and pharmacy makes this approach particularly attractive.

    3. C[BOND]H Functionalization

      Copper-Catalyzed Intramolecular Oxidative C[BOND]H Functionalization and C[BOND]N Formation of 2-Aminobenzophenones: Unusual Pseudo-1,2-Shift of the Substituent on the Aryl Ring (pages 460–464)

      Pang-Chi Huang, Dr. Kanniyappan Parthasarathy and Prof. Dr. Chien-Hong Cheng

      Article first published online: 12 DEC 2012 | DOI: 10.1002/chem.201203859

      Thumbnail image of graphical abstract

      A good move: A copper-catalyzed intramolecular oxidative C[BOND]H functionalization of 2-aminobenzophenone affords two regioisomeric acridones (see scheme). The reaction involves an unusual pseudo-1,2-migration of R2 group(s) on the arene ring (bpy=2,2′-bipyridine, DMAc=dimethylacetimide).

    4. Biosensors

      A New Indicator for Potassium Ions at Physiological pH by Using a Macrocyclic Luminescent Metal Complex (pages 465–468)

      Prof. Xi Yan, Shasha Lv and Rong Guo

      Article first published online: 7 DEC 2012 | DOI: 10.1002/chem.201202925

      Thumbnail image of graphical abstract

      Anyone for a π-type sandwich? A luminescent indicator was developed based on the potassium-binding-induced conformational change of a macrocyclic terbium complex. The indicator adopts a random coil conformation in the absence of K+. In the presence of K+, it forms a π-type sandwich complex with the arene, resulting in an effective energy transfer and strong luminescence (see figure).

      Corrected by:

      Retraction: Retraction: A New Indicator for Potassium Ions at Physiological pH by Using a Macrocyclic Luminescent Metal Complex

      Vol. 19, Issue 19, 5783, Article first published online: 2 MAY 2013

    5. Solid-State Molecular Capsules

      Stabilization and Controlled Release of Reactive Molecules by Solid-State van der Waals Capsules (pages 469–473)

      Dr. Wei Wei, Wanlong Li, Dr. Zhongfeng Li, Prof. Weiping Su and Prof. Maochun Hong

      Article first published online: 18 DEC 2012 | DOI: 10.1002/chem.201203551

      Thumbnail image of graphical abstract

      Control by encapsulation: A dimeric capsule assembled from a tripodal host by van der Waals forces can stabilize a series of reactive molecules, such as cyclopentadiene and trichlorosilane, in the crystalline state even under relatively harsh conditions. Moreover, these reactive molecules can be controllably released into liquid media for further chemical reaction by thermal programming, leaving the insoluble host molecules behind for easy separation and reuse (see scheme).

    6. Asymmetric Catalysis

      Double Axially Chiral Bisphosphorylimides Catalyzed Highly Enantioselective and Efficient Friedel–Crafts Reaction of Indoles with Imines (pages 474–478)

      Kun Wu, Dr. Yi-Jun Jiang, Yan-Sen Fan, Di Sha and Prof. Dr. Suoqin Zhang

      Article first published online: 5 DEC 2012 | DOI: 10.1002/chem.201202900

      Thumbnail image of graphical abstract

      Cool cats: 1,1′-Bi-2-naphthol and vaulted 3,3′-biphenanthrol-type bisphosphorylimides enabled the atom-economical and highly enantioselective Friedel–Crafts reaction between indoles and N-tosylimines with a low catalyst loading (see scheme). A very small amount of 4-(dimethylamino)pyridine (DMAP) suppressed the bisindole side product efficiently. The ortho-substituted aldimine substrates performed excellently in this catalytic system.

    7. Enantioselectivity

      Colorimetric Enantiorecognition of Oligopeptide and Logic Gate Construction Based on DNA Aptamer–Ligand–Gold Nanoparticle Interactions (pages 479–483)

      Jiangtao Ren, Prof. Jiahai Wang, Prof. Jin Wang and Prof. Erkang Wang

      Article first published online: 11 DEC 2012 | DOI: 10.1002/chem.201202430

      Thumbnail image of graphical abstract

      At the gate: Colorimetric enantiorecognition of one oligopeptide was realized by virtue of a D-enantiomer specific DNA aptamer as chiral selector and unmodified gold nanoparticles as indicator. Oligopeptide enantiomers as inputs were introduced into colorimetric logic gates, which have the potential for enantiorecognition of oligopeptides (see figure). This system may lead to a better understanding of chiral recognition for information processing in natural systems.

    8. Deuterated Alkenes

      Site-Selective Deuterated-Alkene Synthesis with Palladium on Boron Nitride (pages 484–488)

      Yuki Yabe, Dr. Yoshinari Sawama, Dr. Yasunari Monguchi and Prof. Dr. Hironao Sajiki

      Article first published online: 7 DEC 2012 | DOI: 10.1002/chem.201203337

      Thumbnail image of graphical abstract

      Heavy stuff: A triethylamine-mediated H–D exchange reaction for the conversion of unlabeled alkynes (1) into [D1]alkynes ([D1]-1) in a mixture of D2O/THF has been developed. Furthermore, the efficient preparation of site- and regioselectively deuterated alkenes ([Dn]-2) from 1 or [D1]-1 with palladium on boron nitride (Pd/BN) as the catalyst and gaseous H2 or D2 is discussed. The resulting deuterated products are attractive and powerful tools for the synthesis of labeled compounds that are useful across a range of scientific fields (see scheme).

    9. Supramolecular Chemistry

      Anion Influence in Directing and Altering the Stereochemistry of the Double [2+2] Reaction of Bis-Pyridyl Dienes in their Silver Complexes: A Green Synthetic Route (pages 489–493)

      Ramkinkar Santra, Mousumi Garai, Debiprasad Mondal and Dr. Kumar Biradha

      Article first published online: 11 DEC 2012 | DOI: 10.1002/chem.201201797

      Thumbnail image of graphical abstract

      Getting selectively organized: Molecules of bis-pyridyl dienes have been stereoselectively photodimerized to form their strained double [2+2] reaction products by using argentophilic forces (see scheme). A pronounced influence of anions and the efficiency of a mechanochemical synthesis have also been described.

  6. Full Papers

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

      Template-Free Synthesis of Hierarchical Vanadium-Glycolate Hollow Microspheres and Their Conversion to V2O5 with Improved Lithium Storage Capability (pages 494–500)

      Dr. Anqiang Pan, Ting Zhu, Hao Bin Wu and Prof. Xiong Wen (David) Lou

      Article first published online: 28 NOV 2012 | DOI: 10.1002/chem.201203596

      Thumbnail image of graphical abstract

      Put to V-good use! Nanosheet-assembled hierarchical V2O5 hollow microspheres were successfully obtained from V-glycolate precursor hollow microspheres, which were synthesized by a simple template-free solvothermal method. When evaluated as cathode materials for lithium-ion batteries, the as-prepared hierarchical V2O5 hollow spheres exhibit high specific capacity, excellent rate capability, and cycling stability (see figure).

    2. Electrocatalysis

      Structure-Dependent Electrocatalysis of Ni(OH)2 Hourglass-like Nanostructures Towards L-Histidine (pages 501–508)

      Dr. Jianwei Nai, Zhengbo Chen, Haopeng Li, Fangyuan Li, Yang Bai, Prof. Lidong Li and Lin Guo

      Article first published online: 18 DEC 2012 | DOI: 10.1002/chem.201203009

      Thumbnail image of graphical abstract

      Structure-dependent performance: Three different types of Ni(OH)2 with hexagonal, truncated trigonal, and trigonal hourglass-like nanostructures, respectively, were deliberately chosen as electrode modifiers to demonstrate the correlation between the structures and their electrocatalytic performance toward L-histidine (see figure). The electrocatalytic activity of these unique nanostructures depends not only their external architecture, but also on their relevant internal degree of crystallinity.

    3. Energetic Materials

      Synthesis of Thermally Stable Energetic 1,2,3-Triazole Derivatives (pages 509–518)

      A. Sudheer Kumar, Vikas D. Ghule, S. Subrahmanyam and Prof. Dr. Akhila K. Sahoo

      Article first published online: 26 NOV 2012 | DOI: 10.1002/chem.201203192

      Thumbnail image of graphical abstract

      A series of thermally stable polynitro-containing benzyl-/aryl- and pyridyl-tethered 1,2,3-triazoles have been efficiently synthesized (see figure). Most of these materials exhibited high positive heats of formation, good thermal stabilities, reasonable densities, and acceptable detonation properties that were comparable to those of TNT. Some of these molecules could be useful as melt-cast explosives and energetic oxidizers.

    4. Density Functional Theory

      Halogen Bonding from a Hard and Soft Acids and Bases Perspective: Investigation by Using Density Functional Theory Reactivity Indices (pages 519–530)

      Dr. Balazs Pinter, Nick Nagels, Prof. Wouter A. Herrebout and Prof. Frank De Proft

      Article first published online: 21 NOV 2012 | DOI: 10.1002/chem.201202567

      Thumbnail image of graphical abstract

      Hard and soft: The relative magnitudes of electrostatic and charge-transfer interactions, as hard and soft components of halogen bonds, are systematically investigated. Like the electrostatic σ hole, a highly directional orbital σ hole is evidenced by the dual descriptors of conceptual DFT. Natural orbital for chemical valence (NOCV) orbitals quantify the density deformation upon halogen-bond formation, whereas low gradient–low density regions indicate their non-covalent nature (see figure; MEP=molecular electrostatic potential, NCI=non-covalent interaction).

    5. Structure–Activity Relationships

      Toward Libraries of Biotinylated Chondroitin Sulfate Analogues: From Synthesis to In Vivo Studies (pages 531–540)

      Dr. Guillaume Despras, Clémence Bernard, Anthony Perrot, Laurent Cattiaux, Prof. Alain Prochiantz, Dr. Hugues Lortat-Jacob and Dr. Jean-Maurice Mallet

      Article first published online: 14 NOV 2012 | DOI: 10.1002/chem.201202173

      Thumbnail image of graphical abstract

      Speedy synthesis of CS-E analogues: Chondroitin sulfate-E (CS-E) oligosaccharidic analogues (di to hexa), in which the 2-acetamido group was replaced by a hydroxyl group to speed up the synthesis, were prepared. Large oligosaccharides were constructed in a few steps from a lactose-originated block. To allow easy biological evaluation, CS-E analogues were prepared in their biotinylated forms and in their unconjugated forms (see figure).

    6. Polymers

      Controlled Chain-Scission of Polybutadiene by the Schwartz Hydrozirconation (pages 541–548)

      Jun Zheng, Yichao Lin, Feng Liu, Haiying Tan, Yanhui Wang and Prof. Dr. Tao Tang

      Article first published online: 8 NOV 2012 | DOI: 10.1002/chem.201202942

      Thumbnail image of graphical abstract

      Severing the ties: Hydrozirconation (stoichiometric or catalytic) of diene-based polymers was found to show a well-controlled chain-scission process (see scheme). Molecular weights of the products could be quasi-quantitatively controlled by the feeding ratio, irrespective of the starting materials. Hydrozirconation of model samples revealed that the existence of multiple double bonds in the linear chain is essential for chain cleavage.

    7. Molecular Modeling

      Structural and Dynamic Basis of Human Cytochrome P450 7B1: A Survey of Substrate Selectivity and Major Active Site Access Channels (pages 549–557)

      Ying-Lu Cui, Ji-Long Zhang, Prof. Qing-Chuan Zheng, Rui-Juan Niu, Yu Xu, Prof. Hong-Xing Zhang and Chia-Chung Sun

      Article first published online: 23 NOV 2012 | DOI: 10.1002/chem.201202627

      Thumbnail image of graphical abstract

      Finding the way: CYP7B1 is a steroid cytochrome P450 7α-hydroxylase that provides the primary metabolic routes for endogenous and exogenous substrates (see figure). In this study, analysis of binding free energy, total interaction energy, and access channels clearly identify the dominant access channels and critical residues that are responsible for ligand binding.

    8. Fullerenes

      Coordinative Interactions between Porphyrins and C60, La@C82, and La2@C80 (pages 558–565)

      Dr. Takahiro Tsuchiya, M. Sc. Marc Rudolf, Dr. Silke Wolfrum, Dr. Shankara Gayathri Radhakrishnan, Ryo Aoyama, Yuya Yokosawa, Azusa Oshima, Prof. Dr. Takeshi Akasaka, Prof. Dr. Shigeru Nagase and Prof. Dr. Dirk M. Guldi

      Article first published online: 23 NOV 2012 | DOI: 10.1002/chem.201202661

      Thumbnail image of graphical abstract

      The La′s: Pyridyl-functionalized La@C82 and La2@C80, as well as C60, were synthesized and integrated as electron acceptors into coordinatively bound donor/acceptor hybrids with zinc tetraphenylporphyrin.

    9. Carbon

      Improvement of the Visible-Light Photocatalytic Performance of TiO2 by Carbon Mesostructures (pages 566–577)

      Wei Wei, Dr. Chao Yu, Qingfei Zhao, Prof. Guisheng Li and Prof. Ying Wan

      Article first published online: 7 DEC 2012 | DOI: 10.1002/chem.201202691

      Thumbnail image of graphical abstract

      Mesostructure photocatalysis: A mesoporous carbon–titania composite showed excellent adsorption–catalysis cycles in the elimination of azo dyes (see figure). The mesostructure, which incorporates mesopores, carbon-pore walls, and carbon-doped anatase nanoparticles formed by interaction between carbon and titania and immobilized within the framework, is responsible for the improved photocatalytic performance and reusability.

    10. Higher Fullerenes

      Synthesis, Structure, and Theoretical Study of Trifluoromethyl Derivatives of C84(22) Fullerene (pages 578–587)

      Kaichin Chang, Maria A. Fritz, Dr. Nadezhda B. Tamm, Dr. Alexey A. Goryunkov, Prof. Lev N. Sidorov, Dr. Chuanbao Chen, Prof. Shangfeng Yang, Prof. Erhard Kemnitz and Prof. Sergey I. Troyanov

      Article first published online: 23 NOV 2012 | DOI: 10.1002/chem.201202568

      Thumbnail image of graphical abstract

      CF3 addition to fullerenes: Trifluoromethylation followed by HPLC separation and X-ray study expands the chemistry of the most abundant higher fullerene, C84 isomer 22. The addition patterns of nine experimental isomers (C84(22)(CF3)12,14,16,20) and the most stable theoretical isomers of C84(22)(CF3)2–10 obey two main CF3 addition rules: no addition at triple-hexagon-junction positions and addition only at para positions in cage hexagons (see figure).

    11. Copper Complexes

      Template Syntheses of Copper(II) Complexes from Arylhydrazones of Malononitrile and their Catalytic Activity towards Alcohol Oxidations and the Nitroaldol Reaction: Hydrogen Bond-Assisted Ligand Liberation and E/Z Isomerisation (pages 588–600)

      Dr. Maximilian N. Kopylovich, Dr. Archana Mizar, Dr. M. Fátima C. Guedes da Silva, Dr. Tatiana C. O. Mac Leod, Dr. Kamran T. Mahmudov and Prof. Armando J. L. Pombeiro

      Article first published online: 23 NOV 2012 | DOI: 10.1002/chem.201203254

      Thumbnail image of graphical abstract

      An effective assistant: CuII complexes containing arylhydrazones from methylene-active nitriles are effective catalysts and appear to act as suitable Lewis acids for the unprecedented possibility of a resonance-assisted hydrogen bond (RAHB)/coordination-controlled E/Z isomeric transition (see scheme).

    12. Ruthenium Catalysts

      Direct Conjugate Addition of Alkynes with α,β-Unsaturated Carbonyl Compounds Catalyzed by NCN-Pincer Ru Complexes (pages 601–605)

      Dr. Jun-ichi Ito, Kohei Fujii and Prof. Dr. Hisao Nishiyama

      Article first published online: 23 NOV 2012 | DOI: 10.1002/chem.201203380

      Thumbnail image of graphical abstract

      Thinking outside the phebox: NCN-pincer Ru complexes containing bis(oxazolinyl)phenyl ligands (phebox) serve as suitable catalysts in the direct conjugate additions of α,β-unsaturated carbonyl compounds, including ketones, esters, and amides, as well as vinylphosphonates, to give various β-alkynyl carbonyl and phosphonate compounds (see scheme).

    13. Sol–Gel Processes

      Borated Titania, a New Option for the Selective Enrichment of cis-Diol Biomolecules (pages 606–612)

      Shao-Ting Wang, Di Chen, Jun Ding, Bi-Feng Yuan and Prof. Yu-Qi Feng

      Article first published online: 23 NOV 2012 | DOI: 10.1002/chem.201203109

      Thumbnail image of graphical abstract

      Borated titania trap: Monolithic borated titania was prepared by a non-aqueous sol–gel strategy as a new inorganic affinity material for the specific capture of nucleosides, glycopeptides, and glycoproteins (see scheme). Benefiting from the inorganic framework, this material prevented hydrophobic interference during the enrichment procedure.

    14. Fluorescent Probes

      Discriminatory Detection of Cysteine and Homocysteine Based on Dialdehyde-Functionalized Aggregation-Induced Emission Fluorophores (pages 613–620)

      Ju Mei, Yijia Wang, Jiaqi Tong, Jian Wang, Prof. Dr. Anjun Qin, Prof. Dr. Jing Zhi Sun and Prof. Dr. Ben Zhong Tang

      Article first published online: 28 NOV 2012 | DOI: 10.1002/chem.201202969

      Thumbnail image of graphical abstract

      Aldehyde-functionalized fluorogens with aggregation-induced emission (AIE) characteristics have been used as fluorescence “turn-on” probes for the discriminatory detection of cysteine (Cys) over homocysteine (Hcy; see figure). The underlying mechanism for the discrimination is the kinetic difference of the reactions and the solubility difference between the fluorogens and the probe–analyte adducts. This proof-of-concept study indicates that this mechanism may be common to all the dialdehyde-substituted AIE-active molecules.

    15. Iridium Complexes

      Synthesis, One- and Two-Photon Photophysical and Excited-State Properties, and Sensing Application of a New Phosphorescent Dinuclear Cationic Iridium(III) Complex (pages 621–629)

      Dr. Wen-Juan Xu, Dr. Shu-Juan Liu, Xin Zhao, Dr. Ning Zhao, Dr. Zhi-Qiang Liu, Hang Xu, Hua Liang, Prof. Dr. Qiang Zhao, Prof. Dr. Xiao-Qiang Yu and Prof. Dr. Wei Huang

      Article first published online: 11 DEC 2012 | DOI: 10.1002/chem.201202827

      Thumbnail image of graphical abstract

      Relight my f-IrIII: A dinuclear iridium(III) complex exhibits strong two-photon-induced phosphorescent emission with a relatively large two-photon absorption cross-section and can be used as a two-photon-excited phosphorescent probe for fluoride.

    16. NLO Dendrimers

      Using Two Simple Methods of Ar[BOND]ArF Self-Assembly and Isolation Chromophores to Further Improve the Comprehensive Performance of NLO Dendrimers (pages 630–641)

      Wenbo Wu, Prof. Gui Yu, Prof. Yunqi Liu, Prof. Cheng Ye, Prof. Jingui Qin and Prof. Zhen Li

      Article first published online: 23 NOV 2012 | DOI: 10.1002/chem.201202992

      Thumbnail image of graphical abstract

      Avengers assembly: Two series of dendrimers were conveniently prepared in which Ar[BOND]ArF self-assembly and isolation-chromophore effects were used to improve their performance; a very large NLO effect (NLO coefficient: 257 pm V−1) was achieved (see figure).

    17. Calixarenes

      Guest Covalent Capture by a Host: A Biomimetic Strategy for the Selective Functionalization of a Cavity (pages 642–653)

      Dr. Nicolas Menard, Prof. Dr. Olivia Reinaud and Dr. Benoit Colasson

      Article first published online: 20 NOV 2012 | DOI: 10.1002/chem.201202391

      Thumbnail image of graphical abstract

      Just one click! A covalent capture strategy allows for the highly selective monofunctionalization of a calix[6]arene core (see figure). It is based on a Michaelis–Menten enzyme mimic with key factors governing the reactivity, such as substrate/reactant pre-association and pre-organization and cavity embedment. With alcohol substrates, it is shown that product self-coordination can be controlled by a competing exogenous ligand.

    18. Homogeneous Catalysis

      Gold(I)-Catalyzed Divergence in the Preparation of Bicyclic Enol Esters: From Exclusively [3C+2C]-Cycloaddition Reactions to Exclusive Formation of Vinylcyclopropanes (pages 654–664)

      Ryan C. Conyers and Prof. Dr. Benjamin W. Gung

      Article first published online: 13 NOV 2012 | DOI: 10.1002/chem.201202881

      Thumbnail image of graphical abstract

      Sense and sensitivity: The outcome of the AuI-catalyzed reactions of propargyl esters with cyclic vinyl ethers is sensitive to substrate structure (see scheme). The preference for the [3C+2C] cycloaddition pathway may depend on the degree of polarization of the vinyl ether double bond. A more polarized π-bond appears to induce [3C+2C] cycloaddition whereas a less polarized π-bond preferentially undergoes cyclopropanation reactions.

    19. Nitrogen Heterocycles

      Conjugate Addition versus Cycloaddition/Condensation of Nitro Compounds in Water: Selectivity, Acid–Base Catalysis, and Induction Period (pages 665–677)

      Dr. Luca Guideri, Prof. Francesco De Sarlo and Prof. Dr. Fabrizio Machetti

      Article first published online: 14 NOV 2012 | DOI: 10.1002/chem.201202698

      Thumbnail image of graphical abstract

      Water at work: Nitroacetate derivatives in water spontaneously condense with electron-poor dipolarophiles to give 4,5-dihydroisoxazoles (see blue plot in scheme). The reaction is base-catalyzed, as evidenced by the kinetic profile (see red plot in scheme). The observed induction times are consistent with a multistep process including the tautomerization. The reaction is compatible with the presence of ammonium, carboxy, and carboxyamide groups.

    20. Synthetic Methods

      Direct Nucleophilic Addition to N-Alkoxyamides (pages 678–684)

      Yuta Yanagita, Hugh Nakamura, Kenji Shirokane, Yusuke Kurosaki, Dr. Takaaki Sato and Prof. , Dr. Noritaka Chida

      Article first published online: 14 NOV 2012 | DOI: 10.1002/chem.201202639

      Thumbnail image of graphical abstract

      The direct approach: Direct nucleophilic addition to N-alkoxyamides installed two different functional groups on amide carbonyl moieties in one pot (see scheme). The N-alkoxy group eliminated the need for an extra preactivation step, which is generally essential for nucleophilic addition to inert amide carbonyl groups. The intermediate chelated through the N-alkoxy group prevented extra addition of the first nucleophile. The reaction generally proceeded in high yield and with wide substrate scope.

    21. Supramolecular Chemistry

      Lyotropic Supramolecular Helical Columnar Phases Formed by C3-Symmetric and Unsymmetric Rigid Molecules (pages 685–690)

      Daoliang Wang , Dr. Youju Huang , Junjun Li, Lu Xu, Mingming Chen, Jiaojiao Tao and Prof. Dr. Liangbin Li

      Article first published online: 14 NOV 2012 | DOI: 10.1002/chem.201202944

      Thumbnail image of graphical abstract

      Supramolecular liquid crystals: Rigid three-armed molecules with C3-symmetric or unsymmetric structures —due to the presence of one, two, or three ionic groups at the molecular periphery —assemble to hexagonal columnar liquid crystals, with chiral symmetry breaking in water in an unexpected triple-stranded helical fashion (see figure). The assembled helical hollow columns, which are stable and robust, show anisotropic ionic conductivity when aligned by fluid shear.

    22. NMR Spectroscopy

      On the Solution Behaviour of Benzyllithium⋅(−)-Sparteine Adducts and Related Lithium Organyls – A Case Study on Applying 7Li,15N{1H} HMQC and Further NMR Methods, Including Some Investigation into Asymmetric Synthesis (pages 691–701)

      María Casimiro, Dr. Pascual Oña-Burgos, Dr. Jens Meyer, Steffen Styra, Dr. Istemi Kuzu, Prof. Dr. Frank Breher and Prof. Dr. Ignacio Fernández

      Article first published online: 23 NOV 2012 | DOI: 10.1002/chem.201202346

      Thumbnail image of graphical abstract

      To pair or not to pair: 2D 7Li,15N heteronuclear shift correlation has been applied to several lithiumorganyls consisting of polydentate N ligands such as N,N,N′,N′-tetramethylethylenediamine, N,N,N′,N′,N′′-pentamethyldiethylentriamine and (−)-sparteine. In combination with other spectroscopic techniques, details on the formation of the lithiumorganyl–polyamine adducts the strength of ion pairing in solution have been explored (see figure).

    23. Photochemistry

      Change of Boron Substitution Improves the Lasing Performance of Bodipy Dyes: A Mechanistic Rationalisation (pages 702–708)

      Krishna K. Jagtap, Neelam Shivran, Soumyaditya Mula, Devidas B. Naik, Sisir K. Sarkar, Tulsi Mukherjee, Dilip K. Maity and Alok K. Ray

      Article first published online: 13 NOV 2012 | DOI: 10.1002/chem.201202699

      Thumbnail image of graphical abstract

      Photostable dyes: Two different congeners of the commercially available Bodipy dye PM567 have been designed and synthesised by substitution at the boron centre and/or at both the boron centre and the meso position. Both congeners show high lasing efficiencies and increased photostability. The substitution at the boron centre reduced the 1O2-generation capacity of the dyes and their reaction rates with 1O2, thereby enhancing their lifetimes under lasing conditions (see figure).

    24. Desulfurization

      Deep Desulfurization by Amphiphilic Lanthanide-Containing Polyoxometalates in Ionic-Liquid Emulsion Systems under Mild Conditions (pages 709–715)

      Junhua Xu, Shen Zhao, Yuanchun Ji and Prof. Yu-Fei Song

      Article first published online: 14 NOV 2012 | DOI: 10.1002/chem.201202595

      Thumbnail image of graphical abstract

      Mild-mannered POM: Highly efficient deep desulfurization with 100 % conversion of dibenzothiophene could be achieved under mild conditions in only 14 min with the (DDA)9LaW10/ [omim]PF6 catalyst system. Deep desulfurization proceeds smoothly in model oil with a S content as low as 50 ppm, and a scaled-up experiment with 1 L of model oil showed that about 99 % sulfur removal can be realized in 40 min in the three-liquid-phase microemulsion system (see figure). DDA=dimethyldioctadecylammonium, omim=1-octyl-3-methylimidazolium.

    25. Chiral Allenes

      tert-Butyldimethylsilyl-Directed Highly Enantioselective Approach to Axially Chiral α-Allenols (pages 716–720)

      Juntao Ye, Wu Fan and Prof. Dr. Shengming Ma

      Article first published online: 9 NOV 2012 | DOI: 10.1002/chem.201201948

      Thumbnail image of graphical abstract

      Protect and direct: tert-Butyldimethylsilyl (TBS) functions as a sterically directing group to achieve excellent enantioselectivity and prevention of possible in situ allene racemization. A straightforward synthesis of axially chiral α-allenols was realized from TBS-protected propargylic alcohols, aldehydes, and the chiral secondary amine (S)-4 or its enantiomer, followed by desilylation (see scheme).

    26. Click Chemistry

      A Carborane-Derivative “Click” Reaction under Heterogeneous Conditions for the Synthesis of a Promising Lipophilic MRI/GdBNCT Agent (pages 721–728)

      Dr. Antonio Toppino, Maria Elena Bova, Dr. Simonetta Geninatti Crich, Dr. Diego Alberti, Prof. Eliano Diana, Dr. Alessandro Barge, Prof. Silvio Aime, Prof. Paolo Venturello and Dr. Annamaria Deagostino

      Article first published online: 14 NOV 2012 | DOI: 10.1002/chem.201201634

      Thumbnail image of graphical abstract

      Talented agent: A lipophilic Gd boron neutron-capture therapy/magnetic resonance imaging (MRI) agent was synthesised by a Huisgen reaction under heterogeneous conditions. MRI was performed on tumour melanoma cells incubated in the presence of stable adducts of this dual agent with low-density lipoprotein to verify the potential of this molecule as a therapeutic agent (see scheme).

    27. Glycoclusters

      Probing the Nature of the Cluster Effect Observed with Synthetic Multivalent Galactosides and Peanut Agglutinin Lectin (pages 729–738)

      Dr. Mehdi Almant, Amira Mastouri, Laura Gallego-Yerga, Prof. José Manuel García Fernandez, Prof. Carmen Ortiz Mellet, Prof. José Kovensky, Dr. Sandrine Morandat, Dr. Karim El Kirat and Dr. Sébastien G. Gouin

      Article first published online: 21 NOV 2012 | DOI: 10.1002/chem.201202319

      Thumbnail image of graphical abstract

      Gang of galactosides: A set of multi-galactosides with a high structural homology has been designed. The nature of a cluster effect observed by enzyme-linked lectin assay (ELLA) with the peanut agglutinin lectin was thoroughly investigated by atomic force microscopy (AFM; see figure). Similar unbinding forces were registered, multiple binding events were never observed, and the bond lifetime increased with valency. These results suggest a cluster effect that operates solely through a bind-and-recapture mechanism of the tethered galactosides.

    28. Ytterbium Complexes

      Light-Harvesting Ytterbium(III)–Porphyrinate–BODIPY Conjugates: Synthesis, Excitation-Energy Transfer, and Two-Photon-Induced Near-Infrared-Emission Studies (pages 739–748)

      Tao Zhang, Xunjin Zhu, Wai-Kwok Wong, Hoi-Lam Tam and Wai-Yeung Wong

      Article first published online: 20 NOV 2012 | DOI: 10.1002/chem.201202613

      Thumbnail image of graphical abstract

      So NIR and yet: Ytterbium–porphyrinate complexes that were conjugated with BODIPY dyes were prepared and fully characterized (see figure). Their photophysical properties, in particular the NIR emissions that corresponded to the YbIII ion, as well as the energy transfer between the donors and the acceptors, were investigated in detail. Moreover, the nonlinear (two-photon-absorption) properties of these complexes were examined.

    29. Chromophores

      Synthesis and Two-Photon Absorption Property Characterizations of Small Dendritic Chromophores Containing Functionalized Quinoxaliniod Heterocycles (pages 749–760)

      Prof. Tzu-Chau Lin, Ying-Hsuan Lee, Che-Yu Liu, Bor-Rong Huang, Ming-Yu Tsai, Yu-Jhen Huang, Prof. Ja-Hon Lin, Yu-Kai Shen and Cheng-Yu Wu

      Article first published online: 21 NOV 2012 | DOI: 10.1002/chem.201202178

      Thumbnail image of graphical abstract

      Catch photons if you can: A series of small dendritic chromophores containing functionalized quinoxaline and quinoxalinoid units has been synthesized and experimentally shown to possess strong and wide-dispersed two-photon absorption in the near-IR region under the irradiation of either femtosecond or nanosecond laser pulses (see figure). It was also demonstrated that such molecular archetype could be promising candidates for optical-power attenuators and stabilizers against laser pulses with long duration.

    30. Asymmetric Synthesis

      Diversity-Oriented Enantioselective Synthesis of Highly Functionalized Cyclic and Bicyclic Alcohols (pages 761–770)

      Bin Mao, Dr. Martín Fañanás-Mastral, Dr. Martin Lutz and Prof. Dr. Ben L. Feringa

      Article first published online: 29 NOV 2012 | DOI: 10.1002/chem.201202859

      Thumbnail image of graphical abstract

      High [5,5]: The diversity-oriented synthesis of cyclic and bicyclic alcohols was achieved by copper-catalyzed hetero-allylic asymmetric alkylation (h-AAA)/cyclization and cycloaddition with excellent chemo-, regio-, and enantioselectivities.

    31. Epoxidation

      On the Catalytic Mechanism of (S)-2-Hydroxypropylphosphonic Acid Epoxidase (HppE): A Hybrid DFT Study (pages 771–781)

      Anna Miłaczewska, Prof. Ewa Broclawik and Dr. Tomasz Borowski

      Article first published online: 13 NOV 2012 | DOI: 10.1002/chem.201202825

      Thumbnail image of graphical abstract

      Profiling mechanisms: The mechanism of oxidative ring closing that leads to the antibiotic fosfomycin was studied with quantum chemistry methods. For the native substrate ((S)-HPP)), the reaction involves generation of the reactive FeIV[DOUBLE BOND]O species, which is responsible for the C[BOND]H bond cleavage. For activation of the weaker C[BOND]H bond in (R)-HPP, FeIII[BOND]O2. is sufficient (see scheme).

    32. Hydrogen Production

      [RhIII(dmbpy)2Cl2]+ as a Highly Efficient Catalyst for Visible-Light-Driven Hydrogen Production in Pure Water: Comparison with Other Rhodium Catalysts (pages 782–792)

      Thibaut Stoll, Dr. Marcello Gennari, Dr. Isabel Serrano, Dr. Jérôme Fortage, Dr. Jérôme Chauvin, Dr. Fabrice Odobel, Dr. Mateusz Rebarz, Dr. Olivier Poizat, Dr. Michel Sliwa, Dr. Alain Deronzier and Dr. Marie-Noëlle Collomb

      Article first published online: 21 NOV 2012 | DOI: 10.1002/chem.201202555

      Thumbnail image of graphical abstract

      Hydrogen from water: The [RhIII(dmbpy)2Cl2]+ complex behaves as a very active catalyst towards H2 evolution in pure aqueous solution when irradiated with visible light in the presence of [Ru(bpy)3]2+ as photosensitizer and ascorbate salt as electron donor (see figure, TON=turnover number). Comparative studies with other well-known rhodium complexes show that this complex is by far the most efficient H2-evolving catalyst in water.

SEARCH

SEARCH BY CITATION