Additive-Controlled Divergent Synthesis of Indole and 4H-Benzo[d][1,3]oxazine Derivatives: Palladium-Catalyzed Carbonylative Cyclization of 2-Alkynylanilines and Benzyl Chlorides.

A palladium-catalyzed divergent carbonylative synthesis of indoles and 4H-benzo[d][1,3]oxazines from 2-alkynylanilines and benzyl chlorides with benzene-1,3,5-triyl triformate (TFBen) as the CO source has been developed. The reaction using AlCl3 as the additive produced various indoles in high yields, while a series of 4H-benzo[d][1,3]oxazines was achieved in moderate yields with AcOH as the additive.