Synthesis of Functionalized Indoles via Palladium-Catalyzed Aerobic Oxidative Cycloisomerization of o-Allylanilines

An efficient strategy for the synthesis of 3-substituted 2-benzylindoles from stable and readily available o-allylanilines, prepared from anilines and allyl alcohols, has been developed. The reaction occurred via a regioselective 5-exo-trig intramolecular oxidative cycloisomerization using Pd(OAc)(2) as catalyst and molecular oxygen as an oxidant. The reaction showed a broad substrate scope with good to excellent yields.