Synthesis of 3-indolyl all-carbon quaternary centers via Rh/Brønsted acid co-catalyzed three-component reactions of azoalkenes with indoles and diazoacetates

Abstract

Highly diastereoselective three-component reactions of azoalkenes with indoles and diazoacetates have been developed via a Rh/Brønsted acid co-catalyzed strategy. These transformations provide efficient construction of a range of 3-indolyl all-carbon quaternary centers in good yields and diastereoselectivities. This reaction is proposed to proceed through Michael-type trapping of zwitterionic intermediates generated from metal carbenes and indoles.