Benzimidazolium Naphthoxide Betaine Is a Visible Light Promoted Organic Photoredox Catalyst.

Benzimidazolium naphthoxide (- ONap-BI+ ) was first synthesized and utilized as an unprecedented betaine photoredox catalyst. Photoexcited state of - ONap-BI+ generated by visible light irradiation catalyzes the reductive deiodination as well as desulfonylation reactions in which 1,3-dimethyl-2-phenylbenzimidazoline (Ph-BIH) cooperates with as an electron and hydrogen atom donor. Significant solvent effects on the reaction progress were discovered, and specific solvation toward imidazolium and naphthoxide moieties of - ONap-BI+ was proposed.