For green and sustainable chemistry, molecular oxygen is considered as an ideal oxidant due to its natural, inexpensive, and environmentally friendly characteristics, and therefore offers attractive academic and industrial prospects. This critical review introduces the recent advances over the past 5 years in transition-metal catalyzed reactions using molecular oxygen as the oxidant. This review highlights the scope and limitations, as well as the mechanisms of these oxidation reactions (184 references).

Copper salts have been developed as versatile catalysts for oxidative coupling reactions in organic synthesis. During these processes, Cu-catalysts are often proposed to serve as a one-electron oxidant to promote the single-electron transfer process. Recently, the transition-metal catalyzed direct dehydrogenative transformation has attracted considerable attention. This tutorial review summarizes the recent advances in the copper-catalyzed dehydrogenative functionalization via a single electron transfer (SET) process achieving C–C, C–N, C–O, C–halogen atoms, C–P, and N–N bond formation.