Copper-Catalyzed Synthesis of N -Aryl and N -Sulfonyl Indoles from 2-Vinylanilines with O 2 as Terminal Oxidant and TEMPO as Co-Catalyst.

A copper-catalyzed intramolecular alkene oxidative amination that utilizes TEMPO as co-catalyst and O ₂ as the terminal oxidant has been developed. The method furnishes N -aryl and N -sulfonyl indoles from N -aryl and N -sulfonyl 2-vinylanilines, respectively. Additionally, sequential copper-catalyzed reactions where initial Chan-Lam coupling of 2-vinylanilines with arylboronic acids is followed by oxidative amination of the alkene can generate N -aryl indoles in one pot.