coordination of different metal ions at enantiotopic positions of an achiral meso‐ligand are reported. These catalysts exhibit a pseudo‐Cs symmetry and are able to catalyze reactions demanding simultaneous involvement of two catalytic sites. The latter was demonstrated by application in the asymmetric ring‐opening of meso‐epoxides.
Cr(salen) catalysed asymmetric ring opening reactions of epoxides in room temperature ionic liquids
作者:Choong Eui Song、Chun Rim Oh、Eun Joo Roh、Dong Joon Choo
DOI:10.1039/b004645k
日期:——
Cr(salen) catalysed asymmetric ring opening reactions of epoxides with TMSN3 proceed readily in the roomtemperature ionic liquid 1-butyl-3-methylimidazolium salts ([bmim][X]) with easy catalyst/solvent recycling.
Intramolecular Acceleration of Asymmetric Epoxide Ring-Opening by Dendritic Polyglycerol Salen-Cr<sup>III</sup>Complexes
作者:Juliane Keilitz、Rainer Haag
DOI:10.1002/ejoc.200900241
日期:2009.7
We present the synthesis of symmetrical (pyrrolidine-salen)CrIII complexes immobilized on hyperbranched polyglycerol 1 through linkers of different lengths and their application in the asymmetricring-opening of meso-epoxides. This reaction proceeded through a cooperative bimetallic mechanism and for the polymeric catalysts a positive dendritic effect with regard to the reaction rate was found. In
A readily synthesized cyclic pyrrolysine analogue for site-specific protein “click” labeling
作者:Ziyang Hao、Yanqun Song、Shixian Lin、Maiyun Yang、Yujie Liang、Jing Wang、Peng R. Chen
DOI:10.1039/c1cc00024a
日期:——
A concise route was developed for the facile synthesis of a cyclic pyrrolysine analogue bearing an azide handle. Directed evolution enabled the encoding of this non-natural amino acid in both prokaryotic and eukaryotic cells, which offers a highly efficient approach for the site-specific proteinlabeling using click chemistry.