Cooperation of copper and dioxygen for the site-selective construction of benzo[1,5]diazocin-6(5H)-ones from indoles and enaminone analogues

Abstract

A new route for the preparation of benzo[1,5]diazocines from indoles and enaminone analogues is described. This protocol features easily available substrates, mild reaction conditions, high atom economy, environmentally friendly oxidants and site-selectivity. In addition, a plausible mechanism involving a cascade of copper-catalyzed oxidation/intermolecular cyclization/oxygen-participated intramolecular ring-opening is suggested.