Copper-Catalyzed Dearomatization Reaction via α-Imino Copper Carbenes

The generation of α-imino metal carbenes from readily available alkynes via nitrene transfer has emerged as an important advancement in carbene chemistry, but current methodologies remain constrained to noble-metal catalysts. Additionally, the dearomatization involving α-imino metal carbenes has not been unexplored. In this study, we disclose a copper-catalyzed dearomatization reaction of azides with ynamide-phenol derivatives via α-imino copper carbenes. This protocol enables the practical synthesis of various valuable 1H-pyrido[2,3-b]indoles in generally excellent yields with a broad substrate scope.