Recent advancements in palladium-catalyzed reactions involving molecular oxygen

Oxidation reactions have significant value in organic chemistry, having been in focus continuously due to the high efficiency in building up molecular complexity. In the past few decades, transition metal-catalyzed oxidation reactions have been significantly explored and have played important roles in organic synthesis. Compared to the widely-used oxidants, such as inorganic salts, peroxides, hypervalent iodine reagents and quinones, molecular oxygen (O2), which is natural, inexpensive, and environmentally friendly, is a highly appealing oxidant in academic and industry area for green and sustainable chemistry. Recently, significant advances have been made in palladium-catalyzed reactions using O2 as the oxidant. This critical review highlights some of the recent developments in molecular oxygen-involved Pd-catalyzed oxidation reactions with a focus on mechanistic strategies and new reaction developments.