Oxo/imido heterometathesis of N-sulfinylamines and carbonyl compounds catalyzed by silica-supported vanadium oxochloride
作者:Pavel A. Zhizhko、Anton A. Zhizhin、Dmitry N. Zarubin、Nikolai A. Ustynyuk、Dmitry A. Lemenovskii、Boris N. Shelimov、Leonid M. Kustov、Olga P. Tkachenko、Gayane A. Kirakosyan
DOI:10.1016/j.jcat.2011.07.011
日期:2011.10
with a higher vanadium content are contaminated with a significant amount of d1 vanadium species. The silica-supported vanadium complexes act as heterogeneous catalysts for oxo/imido heterometathesis between N-sulfinylamines and carbonyl compounds affording imines and SO2. Grafting VOCl3 onto silica leads to a dramatic enhancement of its catalytic activity. A novel water-free express method for preparation
通过无水接枝VOCl 3到二氧化硅表面上,制备了一系列二氧化硅负载的钒氧杂配合物。获得的材料已通过拉曼,漫反射FTIR(DRIFT)和UV-vis,51 V固态NMR和X射线光电子能谱,元素分析和N 2物理吸附进行了表征。发现低钒含量(1-5%)的样品主要由分离的四面体d 0单元(SiO)V(O)Cl 2组成,而钒含量较高的材料则被显着污染。 d 1的量钒物种。二氧化硅负载的钒络合物充当N-亚磺酰基胺与提供亚胺和SO 2的羰基化合物之间的羰基/亚胺基异位复分解反应的非均相催化剂。将VOCl 3接枝到二氧化硅上可大大提高其催化活性。已开发出一种新型的无水表达方法,用于制备多种醛和某些酮的亚胺。值得注意的是,这是过渡金属介导的酮的异复酰亚胺化的第一个例子。
Discovery of chiral catalysts by asymmetric activation for highly enantioselective diethylzinc addition to imines: using racemic and achiral diimines as effective activators
作者:Hua Liu、Hai-Le Zhang、Shuang-Jun Wang、Ai-Qiao Mi、Yao-Zhong Jiang、Liu-Zhu Gong
DOI:10.1016/j.tetasy.2005.07.014
日期:2005.9
A library of chiral zinc complexes formed in Situ by the combination of achiral and racemic diimines with 3,3'-di(3,5-ditrifluoromethylphenyl)-BINOL and diethylzinc were evaluated in the asymmetric addition of diethylzine to N-acylimines. In the presence of 10 mol % of chiral ligand 4 and racemic diimine 5, high enantioselectivities of up to 97% ee and yields of up to 96% were achieved for a wide range of aromatic imines in dichloromethane at -30 degrees C. (c) 2005 Elsevier Ltd. All rights reserved.
TRISPHAT-N: A Chiral Hexacoordinated Phosphate Anion with Unique Asymmetric Coordinating Properties
A simple and efficient chiral anionic N-ligand: the introduction of a Lewis basic nitrogen onto the TRISPHAT skeleton allows the direct and efficient stereocontrol of tropos chiral ligands bound to metal complexes or of stereogenic metal centers (dr up to 96:4).
Dual chirality control of palladium(ii) complexes bearing tropos biphenyl diamine ligands
作者:Kohsuke Aikawa、Koichi Mikami
DOI:10.1039/b510910h
日期:——
Axial and center chirality of Pd complexes with tropos biphenyl secondary diamine ligands is shown to be controlled by chiral amide (R)-DABNTf, which can efficiently discriminate between two enantiomeric Pd complexes.