Copper(i)-catalyzed asymmetric [3 + 3] annulation involving aziridines to construct tetrahydro-β-carbolines

Abstract

A catalytic asymmetric [3 + 3] annulation of aziridines with substituted 2-vinylindoles was developed. The reaction proceeds through copper-catalyzed ring-opening of aziridines followed by base-promoted intramolecular aza-Michael addition in a one-pot process. This strategy provides an efficient method for the direct synthesis of 1,4-disubstituted tetrahydro-β-carbolines with generally high diastereo- and enantioselectivities (up to >20 : 1 dr, 96% ee).