Peroxydisulfate as an Oxidant in the Site‐Selective Functionalization of sp 3 C–H Bonds

The development of methodology for the site‐selective functionalization of sp 3 C–H bonds has irrevocably altered the state of organic synthesis. These methods often rely on the use of strong oxidants in conjunction with transition‐metal catalysis. Peroxydisulfate (S 2 O 8 2– ) salts are some of the strongest inorganic oxidants known. They are low‐cost crystalline solids that are stable at room temperature. Harmless sulfate salts are produced as a byproduct of their reactions, allowing S 2 O 8 2– to serve as a ‘green’ alternative to other commonly employed oxidants. Despite these attractive properties, it has only been in the last ten years that the majority of sp 3 C–H functionalization reactions utilizing S 2 O 8 2– for the diversification of complex molecules have been reported. The objective of this review is to provide a useful reference regarding the recent advancement of sp 3 C–H functionalization using S 2 O 8 2– and to inspire the invention of new protocols utilizing this remarkable oxidant.