A green and recyclable approach for synthesizing disulfides

Abstract

Disulfides are important organic intermediates; however, current synthesis methods for disulfides are costly and generate substantial waste pollution. This communication reports, for the first time, a green and recyclable synthetic process for disulfides, using water as the solvent and iodine as the oxidant. At ambient temperature, the oxidation conversion rate of thiol–ethanol to disulfides reaches 99%, with a yield of 98% using a room-temperature extraction and separation process. Iodine is regenerated from iodide ions in the separated reaction mixture using hydrogen peroxide, and the mixture is reused in the synthesis of disulfides with a conversion rate of 99%. This process has been applied to several thiol substrates, achieving conversion rates above 95% for all cases.