Copper-catalyzed synthesis of N-aryl and N-sulfonyl indoles from 2-vinylanilines with O₂ as terminal oxidant and TEMPO as cocatalyst

A copper-catalyzed intramolecular alkene oxidative amination that utilizes TEMPO as cocatalyst and O₂ 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.