Palladium-catalyzed oxidative C-H/C-H cross-coupling of imidazopyridines with azoles.

An effective palladium-catalyzed oxidative C-H/C-H cross-coupling of imidazopyridines with azoles using air as the oxidant has been developed. This protocol provides a straightforward and operationally simple method for the synthesis of 3-azolyl-imidazopyridines in moderate to good yields and with good functional group tolerance. The biological evaluation revealed that the newly synthesized compounds 3e and 3h exhibit significant in vitro antiproliferative activities against human-derived lung cancer cell lines compared with the positive control, 5-fluorouracil.