Recent advances in photocatalytic and transition metal-catalyzed synthesis of disulfide compounds.

Disulfide bonds are essential in protein folding, cellular redox balance, materials science, and drug development. Despite existing synthetic methods, the efficient and selective synthesis of unsymmetrical disulfides remains challenging. This review highlights innovative approaches in visible light photocatalysis, including decarboxylation, deoxydisulfidation of alcohols, and direct C-H disulfidation, showcasing broad substrate applicability and functional group tolerance under mild conditions. Additionally, it explores transition metal-catalyzed systems with copper, nickel, palladium, chromium, Iridium, Rhodium molybdenum, and scandium, offering effective strategies for unsymmetrical disulfide bond formation and late-stage functionalization of complex molecules through reductive coupling, selective oxidation, and novel insertion reactions.