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Gangavaram V. M. Sharma Dr. Bommagani Shoban Babu Kallaganti V. S. Ramakrishna Pendem Nagendar Dr. Ajit C. Kunwar Dr. Peter Schramm Carsten Baldauf Dr. Hans‐Jörg Hofmann Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(22):5552-5566
Origami peptides : A novel class of foldamers consisting of α/δ‐hybrid peptides has been investigated theoretically and experimentally by exploiting the rigidity of the side chain of a new δ‐amino acid prepared from D ‐glucose and D ‐xylose with a furanose side chain (see figure).
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Polymer conformations: The picture shows instantaneous conformations of product molecules produced in a catalytic reaction at the head of a polymer chain. The extended (left) and collapsed (right) polymers correspond to chains in good and poor solvent conditions, respectively. The product molecule concentration gradient leads to a directed force on the polymer, so that it functions as a self‐propelled nanomotor.
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Maggie C. C. Ng Donald J. Craig Dr. Jason B. Harper Dr. Lambert van‐Eijck Dr. John A. Stride Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(27):6569-6572
Size matters! The structure and dynamics of the tetratolyl Group 14 elements, which were probed by using high‐resolution inelastic neutron scattering spectra, show a remarkable dependence on the size of the central atom. The para‐methyl groups at the periphery of the molecules constitute the frontier intermolecular interactions of increasingly larger tetrahedra, which becomes critical at the molecular radius of the Si and Ge analogues (see picture).
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Renhua Qiu Guoping Zhang Yuyang Zhu Xinhua Xu Lingling Shao Yinhui Li Delie An Shuangfeng Yin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(26):6488-6494
Stable complexes : An extremely air‐stable μ2‐hydroxy‐bridged binuclear hafonocene perfluorooctanesulfoante complex shows high catalytic efficiency in Lewis acid‐catalyzed reactions, such as esterification, Friedel–Crafts acylation, the Mukaiyama aldol reation, and the allylation of aldehyde (see scheme).
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Ljiljana Fruk Dr. Chi‐Hsien Kuo Eduardo Torres Dr. Christof M. Niemeyer Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(9):1550-1574
Enzymes with artificial cofactors : Nondiffusible organic cofactors of enzymes can often be replaced by artifical analogues to generate semisynthetic enzymes (see scheme). This approach can be used to study structure–function relationships in enzymology and to produce novel enzymes with enhanced or even entirely new functions that are useful for biosensing, biocatalysis, and materials science applications.
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Christian Hertweck Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(26):4688-4716
Molecular Lego : Polyketides represent a highly diverse group of natural products with structurally intriguing carbon skeletons (see picture) which are assembled from simple acyl building blocks. A combination of chemical, biochemical, and genetics studies have provided exciting new insights into the programming of polyketide assembly and the sophisticated enzymatic machineries involved. This review highlights recent developments in the field.
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Yasuhiro Uozumi Prof. Dr. Yutaka Matsuura Dr. Takayasu Arakawa Dr. Yoichi M. A. Yamada Dr. 《Angewandte Chemie (International ed. in English)》2009,48(15):2708-2710
You oughta use water : Broad functional‐group (FG) tolerance was observed for the title coupling of aryl halides (X=Cl, Br, I) and aryl boronic acids to give biaryl compounds with up to 94 % ee. The chiral imidazoindole phosphine–palladium catalyst supported on an amphiphilic polystyrene–poly(ethylene glycol) (PS–PEG) resin could be recycled readily.
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Michel Ephritikhine Dr. 《Angewandte Chemie (International ed. in English)》2009,48(27):4898-4899
Pincers do something for U that sandwiches don′t : The dead‐ends in the metallocene chemistry of the actinides can be circumvented by using a soft PNP pincer ligand (see scheme). The PNP ligand has been shown to be flexible, hemilabile, and capable of stabilizing low‐ and high‐valent uranium species. The bis(PNP) framework is a valuable alternative to the (C5Me5)2 ligand set, offering distinct structures and reaction patterns.
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Yuliya Rudzevich Dr. Valentyn Rudzevich Dr. Fabian Klautzsch Christoph A. Schalley Prof. Dr. Volker Böhmer Dr. 《Angewandte Chemie (International ed. in English)》2009,48(21):3867-3871
Size and shape do matter : When dimerized in nonpolar solvents, an equimolar mixture of eleven tetra‐urea calix[4]arenes with different wide‐rim substituents self‐sorts into only six out of 35 different homo‐ and heterodimers (see picture). Since the calixarene scaffold and the four urea units are the same in all cases, the self‐sorting process is driven only by the cooperative action of steric requirements and stoichiometry.
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Liqing Ma Dr. Wenbin Lin Prof. 《Angewandte Chemie (International ed. in English)》2009,48(20):3637-3640
Stop the breathing : As the organic bridging ligands become more elaborate and large, the resulting MOFs tend to experience significant framework distortion (i.e., breathing) upon solvent removal. Rigidification of MOFs that are built from elongated tetracarboxylate bridging ligands by unusual interlocking and interpenetration leads to highly porous and robust hybrid materials.
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Dani Peri Sigalit Meker Michal Shavit Edit Y. Tshuva Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(10):2403-2415
Carefully design your ligand! A new family of highly cytotoxic TiIV complexes demonstrates strong dependence of activity on the particular ligand employed, in which small structural modifications dramatically affect both hydrolytic behavior and biological activity (see picture). Different structure‐dependence patterns are observed for hydrolysis and cytotoxicity, which are, nonetheless, strongly related.
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Guillaume Berthon‐Gelloz Dr. Mélanie Marchant Bernd F. Straub Prof. Dr. Istvan E. Marko Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(12):2923-2931
Pd 0 does the trick! Alkenyl silanes are efficiently cyclopropanated by diazoalkanes at low Pd loadings (see scheme). Clear evidence for the involvement of a Pd0 resting state for this reaction is given.
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Xavier Sala Isabel Romero Montserrat Rodríguez Lluís Escriche Antoni Llobet 《Angewandte Chemie (International ed. in English)》2009,48(16):2842-2852
Water into oxygen : A good catalyst for converting water into oxygen is seen as an essential part of any sustainable solar‐energy conversion scheme. Some success has been achieved using molecular complexes as catalysts and the key factors influencing their performance are discussed. The necessity of generating a solid‐state catalytic system is presented and the first attempts to generate supported molecular water‐oxidation catalysts are analyzed.
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M. Becker Dr. Th. Stelzner Dr. A. Steinbrück A. Berger Dr. J. Liu Dr. D. Lerose U. Gösele Prof. Dr. S. Christiansen Dr. 《Chemphyschem》2009,10(8):1219-1224
Gold caps on silicon nanowires are selectively coated with silver by autometallography (electroless deposition). Changing the conditions of silver deposition, a variety of different coating morphologies can be produced (see figure). The different silver coating morphologies are investigated in terms of their capabilities for surface enhanced Raman scattering (SERS) experiments.
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Jonas Lindh Jonas Sävmarker Peter Nilsson Dr. Per J. R. Sjöberg Dr. Mats Larhed Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(18):4630-4636
One Heck of a reaction : Treatment of arylboronic acids or aryltrifluoroborates with vinyl acetate by using a palladium(II) catalyst gives the corresponding styrenes (see scheme). No palladium reoxidant is needed and the vinylation is performed under non‐inert conditions