TMSOTf-Catalyzed Reactions of N-Arylynamides with Sulfilimines To Construct 2-Aminoindoles and -Arylated Amidines

Here, we disclose an efficient TMSOTf-catalyzed C-H annulation of aryl-terminated N-arylynamides with sulfilimines, leading to the practical assembly of various valuable 2-aminoindoles in generally moderate to excellent yields with a broad range of functional groups, while nonaryl terminated N-arylynamides undergo TMSOTf-catalyzed aminative arylation with sulfilimines providing alpha-arylated amidines.