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.