Merging Visible Light with Cross-Coupling: The Photochemical Direct C-H Difluoroalkylation of Imidazopyridines.

A transition-metal-free protocol for the difluoroalkylation of imidazopyridines with bromodifluoroaryl ketones promoted by visible light irradiation is presented. This protocol is distinguished by simple, mild, and catalyst-free reaction conditions with a wide reaction scope, which is complementary to existing difluoroalkylation strategies by photoredox scenarios. Additionally, this protocol potentially offers a new way for streamlining the synthesis of compounds containing the difluoro moiety.