Novel iodine-induced sulfonylation and sulfenylation of imidazopyridines have been described using sodium sulfinates as the sulfur source. This strategy enables highly selective difunctionalization of imidazo[1,2-a]pyridine to access sulfones and sulfides in good yields. A wide range of substrates and functional groups were well-tolerated under optimized conditions. Moreover, control experiments have been conducted, indicating a radical pathway involved in the reaction mechanisms.

A copper­(I)-catalyzed sulfur-bridged dimerization of imidazopyridines has been developed using isothiocyanate as the sulfur source. This method enables a switchable synthesis of bis­(imidazo­[1,2-a]­pyridin-3-yl)­sulfanes or bis­(2-(imidazo­[1,2-a]­pyridin-2-yl)­phenyl)­sulfanes in the presence of 4-dimethylaminopyridine (DMAP) or K2CO3 when different imidazopyridines were employed. Under optimized conditions, a variety of sulfur-bridged imidazopyridines were obtained in good yields. Moreover, thiourea was proved to be the key intermediate under catalytic system A.

An efficient one pot, three component synthesis of C3 sulfonamidomethylated imidazopyridines has been disclosed utilizing methanol and DTBP as the major and minor methylene source, respectively.