Temperature-controlled chalcogenation and chalcogenocyanation of imidazopyridines in water under transition-metal-free conditions.

A sustainable and transition metal-free approach for C3 chalcogenation and chalcogenocyanation of imidazopyridines with KXCN (X = S or Se) has been developed under mild conditions. Importantly, this reaction was performed in the presence of catalytic iodine in aqueous medium, which afforded either chalcogenated or chalcogenocyanated imidazopyridines under temperature control. The current protocol featured a broad substrate scope, transition metal-free and organic solvent-free conditions, operational convenience, and gram-scale production.