Regioselective synthesis of C6-alkylated indoles utilizing electronic–steric effects enabled by imino exchange and phosphorus ylide addition

Abstract

Herein, we report the regioselective synthesis of C6-alkylated indoles utilizing the electronic effect enabled by imino exchange and the steric effect of phosphorus ylide addition. The protocol adopts readily available P-ylides as alkylating reagents and alkylamines, used principally for regulating regioselectivity, from 2-alkynylanilines, to give the desired C6-alkylated indoles (C3–H and N1 with diverse substituents) with excellent regioselectivity.