Synthesis of 4-Alkylindoles from 2-Alkynylanilines via Dearomatization- and Aromatization-Triggered Alkyl Migration.

A simple method for rapid synthesis of 4-alkylindoles from 2-alkynylanilines was reported. The protocol involves an oxidative dearomatization and an aromatization triggered regioselective alkyl migration. A range of alkyl groups including linear, branched, or cycloalkyl groups can be introduced into the C4 position of indole.