Catalyst-Controlled Nickel-Catalyzed Intramolecular endo-Selective C-H Cyclization of Benzimidazoles with Alkenes
Zi-Jian Liu1, Jiang-Fei Li2, Feng-Ping Zhang2
1School of Biotechnology and Health Science, Wuyi University, Jiangmen, Guangdong 529020, China.
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 BuOK base-enabled Ni-Al bimetallic catalyst prove critical to the endo selectivity.
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