Asymmetric and diastereoselective Mannich reactions using hydantoin as a chiral auxiliary
摘要:
The Mannich reaction of titanium enolates of a chiral hydantoin with various aldimines smoothly occurred in good yields and with high anti-diastereoselectivity. The Mannich adducts can be readily cleaved by alcoholysis to afford several beta-amino ester derivatives in good yields and in almost enantiomerically pure form. (C) 2012 Elsevier Ltd. All rights reserved.
作者:Paweł Dydio、Christophe Rubay、Tendai Gadzikwa、Martin Lutz、Joost N. H. Reek
DOI:10.1021/ja208589c
日期:2011.11.2
We report an achiral bisphosphine rhodiumcomplex equipped with a binding site for the recognition of chiral anion guests. Upon binding small chiral guests--cofactors--the rhodiumcomplex becomes chiral and can thus be used for asymmetric catalysis. Screening of a library of cofactors revealed that the best cofactors lead to hydrogenation catalysts that form the products with high enantioselectivity