Asymmetric dearomative reductive arylallylation of indoles with trifluoromethyl alkenes by nickel catalysis

Abstract

Catalytic dearomatization reactions of C2-substituted indoles represent an efficient and powerful way to access polycyclic indolines. Despite significant advances in this field, the corresponding asymmetric reductive dearomative difunctionalization of indoles at the C2 and C3 positions with two electrophilic partners remains a huge challenge due to the difficulty of breaking the aromaticity and constructing the quaternary carbon stereocenters. Herein, we report an unprecedented nickel catalysis strategy for diastereo- and enantioselective dearomative reductive arylallylation of indoles with trifluoromethyl alkenes. The protocol allows the rapid synthesis of gem-difluorinated chiral polycyclic indolines bearing vicinal quaternary and tertiary carbon stereocenters with a wide substrate scope, good functional group tolerance, and excellent diastereo- and enantioselectivities.