Zinc-Catalysed N-Iodosuccinimide-Enabled Selective N2-Olefination of Benzotriazoles with Alkenes

Herein, we describe a zinc-catalysed N-2-selective olefination of benzotriazoles with unactivated alkenes and styrenes. The transformation is achieved by a N-iodosuccinimide (NIS)-mediated two-step, one-pot approach, proceeding through sequential regioselective -iodoalkylation of benzotriazoles with alkenes and a subsequent base-promoted 1,2-elimination. The N-2-selective -iodoalkylation of benzotriazoles is highly stereospecific and works under very simple and mild conditions, exhibiting excellent functional group tolerance. The high N-2-selectivity is attributed to intermolecular hydrogen bonding between the N-iodosuccinimide and the NH hydrogen bond donor at the 1-position of the benzotriazoles. This scalable process, serving as an efficient method for modular assembly of structurally diverse N-2-olefinated benzotriazoles, will significantly contribute to the chemistry of N-2-functionization of benzotriazoles.