Abstract
An aryl ketone mediated synthesis of 2-alkylated benzazoles was achieved via radical
coupling under photoirradiation starting from saturated heterocycles and 2-sulfonylated
benzazoles, such as benzothiazoles, benzoxazole, and benzimidazole. Heterocyclic compounds,
including a cyclic ether, azacycles, and tetrahydrothiophene, were applicable, and
the benzazole unit was site-selectively installed at the carbon center proximal to
the heteroatom. The present transformation takes place at ambient temperature under
neutral reaction conditions without the aid of any metallic catalysts or reagents.
Key words
C–H functionalization - alkylation - benzazoles - photoreaction - aryl ketones