Synthesis of Symmetrical and Unsymmetrical Thiosulfonates from Disulfides through Electrochemically Induced Disulfide Bond Metathesis and Site-Selective Oxidation

The anodic generation of symmetrical and unsymmetrical thiosulfonates is presented. First, the oxidation of disulfides yielding symmetrical thiosulfonates was realized. The direct synthesis is performed using a simple quasi-divided cell design, whereby using a supporting electrolyte is unnecessary. Its principle was then expanded to the conversion of unsymmetrical disulfides that were generated in situ through metathesis of two symmetrical disulfides. This enables a direct access to unsymmetrical thiosulfonates without any pre-functionalization or elaborate synthesis of the starting materials for the first time. The reaction scope was investigated by converting differently functionalized aliphatic and aromatic disulfides in moderate to very good yields. Furthermore, a sensitivity assessment for an improved reproducibility and a robustness screen to determine the compatibility of the reaction against functional groups were performed.