High-efficiency synthesis of sulfenamides and disulfides by electrochemical dehydrogenative coupling

Catalytic dehydrogenative coupling of thiols with amines to produce sulfenamides and disulfides is an important reaction in the industry. Classical synthesis of sulfenamides involves the reaction between amine nucleophiles and sulfonyl chlorides, which are not widely available, toxic and unstable, and the reaction requires a combination of oxidizing and chlorinating reagents. Here we decribe an environmentally benign protocol for the efficient electrochemical dehydrogenative coupling of thiols with amines or thiols to form compounds possessing S–N or S–S bonds. We used potassium iodide as electrocatalyst in methanol for a greener reaction. The reaction operates under ambient conditions in the absence of oxidants, acids/bases or toxic/explosive electrolytes. Results show that most produced sulfenamides and disulfides are generated in yields up to 99%.