Flavin–Iodine‐Catalyzed Aerobic Oxidative Tandem C(<i>sp</i>³)−H Imination and Amination: Synthesis of Fluorescent Imidazo[1,5‐<i>a</i>]pyridines from Pyridylmethanes and Aminomethanes

Abstract Aerobic oxidative tandem C( sp 3 )−H imination and amination between pyridylmethane and aminomethane derivatives was demonstrated using a flavin–iodine‐coupled catalyst. This method provides a simple and atom‐economical synthesis of various 1,3‐substituted imidazo[1,5‐ a ]pyridines with fluorescent properties. The flavin–iodine catalyst efficiently promoted multiple reactions, including the oxygenation of pyridylmethane and subsequent oxidative C−N bond formation, utilizing only molecular oxygen, which is a sustainable ideal oxidant. The resulting 1‐ester‐substituted imidazo[1,5‐ a ]pyridine derivatives exhibited dual‐state emission in both solution and solid states. In particular, imidazo[1,5‐ a ]pyridine with a bulky 2,6‐dichlorophenyl substituent showed an apparent blue emission with good photoluminescence (PL) quantum yields (0.49 in CH 2 Cl 2 solution and 0.39 in the solid state), making it promising candidate for use in optoelectronic devices.