Catalyst-Controlled Nickel-Catalyzed Intramolecular <i>endo</i>-Selective C–H Cyclization of Benzimidazoles with Alkenes
Zijian Liu, Jiang‐Fei Li, Feng‐Ping Zhang, Xue-Tao Xu, Mengchun Ye
Abstract
Compared with the widely explored exo -selective C–H cyclization, transition metal-catalyzed endo -selective C–H cyclization of benzimidazoles with alkenes has been a formidable challenge. Previous efforts mainly rely on substrate-controlled methods, rendering the product complexity restricted. Herein we report a catalyst-controlled method to facilitate endo -cyclization, in which a bulky N -heterocyclic carbene ligand and t BuOK base-enabled Ni–Al bimetallic catalyst prove critical to the endo selectivity.
Topics & Concepts
ChemistryCatalysisBimetallic stripSelectivityCombinatorial chemistryIntramolecular forceCarbeneNickelLigand (biochemistry)Substrate (aquarium)Medicinal chemistryStereochemistryOrganic chemistryOceanographyReceptorBiochemistryGeologyCatalytic C–H Functionalization MethodsSynthesis and Catalytic ReactionsCyclopropane Reaction Mechanisms