Oxidative Cross-Dehydrogenative C–H Bond Amination of Imidazo[1,2-a]pyridines in Aqueous Media under Metal-Free Conditions

Abstract The metal-free direct oxidative cross-dehydrogenative C–H bond amination of imidazopyridines with pyrazole in water as solvent has been developed under K2S2O8-promoted mild conditions. This strategy was applied to variable imidazoheterocycles to give amination products in moderate to good yields. The described protocol also offers scale-up synthesis for the construction of C–N bonds, which makes it suitable for the synthesis of biologically active compounds and pharmaceuticals.