An efficient and optically active, bifunctional tetraaza ligand (2S)-N-(1R,2R)-2-[(S)-pyrrolidine-2-carboxamido]-1,2-diphenylethyl}pyrrolidine-2-carboxamide has been developed for the addition of trimethylsilyl cyanide (TMSCN) to ketones. The bifunctionalcatalyst system based on a monometallic titanium complex was found to be a highly enantioselectivecatalyst to provide O-TMS cyanohydrins with up
Enantioselective hydrosilylation of ketimines catalyzed by Lewis basic C2-symmetric chiral tetraamide
作者:Zhouyu Wang、Siyu Wei、Chao Wang、Jian Sun
DOI:10.1016/j.tetasy.2007.03.008
日期:2007.4
L-Proline derived C-2-symmetric chiral tetraamide 5b was found to behave as an effective Lewis basic catalyst in the enantioselective hydrosilylation of ketimines, affording high isolated yields (up to 95%) and moderate to high enantioselectivities (up to 86% ee) for a broad range of ketimines. A clear synergistic effect of the two identical diamide units of 5b was observed for asymmetric induction. (c) 2007 Elsevier Ltd. All rights reserved.