Stereodivergent Construction of Csp3 -Csp3 Bonds Bearing Vicinal Stereocenters by Synergistic Palladium and Phase-Transfer Catalysis.

Abstract

Synergistic catalysis has emerged as one of the most powerful tools for stereodivergent formation of Csp3 -Csp3 bonds bearing vicinal stereocenters. Despite the many successes that have been achieved in this field, stereodivergent Csp3 -Csp3 coupling reactions involving stabilized nucleophiles remain challenging because of the competing single-catalysis pathway. Herein, we report a synergistic palladium/phase-transfer catalyst system that enables diastereodivergent Csp3 -Csp3 coupling reactions of 1,3-dienes with stabilized nucleophile oxindoles. Both the syn and anti coupling products, bearing quaternary and tertiary vicinal stereocenters, could be selectively produced in good yields with high enantio- and diastereoselectivities. Non-covalent activation of the stabilized nucleophile via chiral ion pair in a biphasic system is a crucial success factor in achieving diastereodivergence.