Diastereoselectivity of tandem Michael addition- alkylation reactions: a convenient method for one-pot synthesis of alpha-branched 2,3-diphenylglutaric acid derivatives

摘要

alpha-Branched 2,3-diphenylglutaric acid derivatives with two adjacent chiral centres are easily obtained by one-pot Michael addition - alkylation sequences. The diastereoselectivity observed, which varies from outstanding to moderate and even low, was found to depend on the type of the metal intermediate (nitrile vs amide) and its gamma-substitution pattern. A rigidly chelated transition state model that correctly predicts the sense of the asymmetric induction is proposed. (C) 2002 Elsevier Science Ltd. All rights reserved. [References: 34]