Synthesis of unsymmetrical disulfides via the cross-dehydrogenation of thiols

Organosulfur compounds with unsymmetrical S–S bonds are usually called unsymmetrical disulfides and are widely used in the biological, medicinal, and chemical fields. Their versatility has guided the development of various new methods for the synthesis of disulfides. In recent years, the synthesis of disulfides by cross-dehydrogenation of thiols has attracted much attention due to its high atomic economy. Herein, this review summarizes progress toward the synthesis of unsymmetrical disulfides under chemical oxidation, electrooxidation, or photocatalysis by cross-dehydrogenation of thiols.