title: A protocol to 2-aminobenzimidazoles via copper-catalyzed cascade addition and cyclization of o-haloanilines and carbodiimides.
abstract: An efficient strategy for the synthesis of a variety of 2-animobenzimidazole derivatives has been developed. The reaction proceeded from o-haloanilines and carbodiimides via copper(I)-catalyzed domino reaction in the presence of tert-butoxide to afford the corresponding 2-animobenzimidazole derivatives in good to excellent yields. o-Haloanilines could be o-iodoaniline, o-bromoaniline, and o-chloroaniline derivatives. Carbodiimides could be symmetrical and unsymmetrical substrates with aryl or alkyl substituents. The reaction exhibited a good regioselectivity when unsymmetrical carbodiimides were employed.
authors.affiliation: Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Shangjun
authors.initials: S
authors.lastname: Cai
authors.forename: Qian
authors.initials: Q
authors.lastname: Liao
authors.forename: Chanjuan
authors.initials: C
authors.lastname: Xi
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D001562:Benzimidazoles / Q000737:chemistry*; D002234:Carbodiimides / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D003500:Cyclization
chemical_list: D000814:Aniline Compounds; D001562:Benzimidazoles; D002234:Carbodiimides; D003300:Copper; C027391:2-aminobenzimidazole; C023650:aniline