Structural Optimization of Enantiopure 2-Cyclialkylamino-2-aryl-1,1-diphenylethanols as Catalytic Ligands for Enantioselective Additions to Aldehydes
摘要:
The structural optimization of a family of modular, enantiopure beta-amino alcohol ligands with a common 2-amino-2-aryl-1,1-diphenylethanol skeleton, whose stereogenicity was introduced through the Jacobsen epoxidation of 1,1-diphenyl-2-arylethylenes, has led to the identification of a small set of optimal catalysts with enhanced activity and enantioselectivity in the addition of alkylzinc and arylzinc reagents to aldehydes. Criteria for the discrimination between apparently analogous, highly enantioselective ligands are proposed.
The structural optimization of a family of modular, enantiopure beta-amino alcohol ligands with a common 2-amino-2-aryl-1,1-diphenylethanol skeleton, whose stereogenicity was introduced through the Jacobsen epoxidation of 1,1-diphenyl-2-arylethylenes, has led to the identification of a small set of optimal catalysts with enhanced activity and enantioselectivity in the addition of alkylzinc and arylzinc reagents to aldehydes. Criteria for the discrimination between apparently analogous, highly enantioselective ligands are proposed.
Synthesis of Heavily Substituted 1,2-Amino Alcohols in Enantiomerically Pure Form
作者:Noemí García-Delgado、Katamreddy Subba Reddy、Lluís Solà、Antoni Riera、Miquel A. Pericàs、Xavier Verdaguer
DOI:10.1021/jo050960+
日期:2005.9.1
simple and convenient methodology for the preparation of optically pure 2-amino-2-aryl-1,1-diphenylethanols is presented. Allylamine was found to produce the ring-opening of triaryloxiranes in a regioselective and a stereospecific fashion. Removal of the allyl protecting group provided the free 1,2-amino alcohols in enantiomericallypure form.