The first example of visible-light-induced deoxygenative C2-sulfonylation of quinoline N-oxides with sulfinic acids in the presence of an organic dye as the catalyst was developed. The reaction conditions are eco-friendly and mild, employing ambient air as the sole oxidant and aqueous acetone solution as the solvent. This approach requires only a very low catalyst loading, allowing gram-scale preparation as well as late-stage modification of biologically active compounds bearing quinoline groups.

A mild and eco-friendly visible-light-induced decarboxylative acylation of quinoxalin-2(1H)-ones and α-oxo carboxylic acids with ambient air as the sole oxidant at room temperature was established. The reaction proceeded efficiently without any metal catalysts, strong oxidants or external-photosensitizers, ultimately reducing the generation of waste.

The first example of selective oxidation of sulfides to sulfones and sulfoxides using molecular oxygen under clean conditions was established. The desired products could be easily collected through recrystallization in large-scale preparation.

Aryl radicals were generated for the first time from cheap and easily available aryl acyl peroxides in eco-friendly ethyl acetate under ambient conditions and visible-light illumination in the absence of any additive, metal catalyst, or external photosensitizer. The present arylation of quinoxalin-2(1H)-ones was chemo- and regioselective, and provided good access to various 3-arylquinoxalin-2(1H)-ones.

A new and efficient visible-light-mediated strategy has been developed for the synthesis of 3-sulfenylated quinoxalin-2(1H)-ones via direct C–H sulfenylation of quinoxalin-2(1H)-ones with thiols in air at room temperature. Through this photochemical reaction, various 3-sulfenylated quinoxalin-2(1H)-ones can be efficiently and conveniently obtained in excellent yields with good functional group tolerance by simple use of rhodamine B as the cheap photocatalyst and air as the green oxidant.