Synthesis of Aryl and Alkyl Sulfonyl Cyanides Using KCN and NaOCl·5H 2 O in a Biphasic System

An efficient and practical protocol has been developed for synthesizing aryl and alkyl sulfonyl cyanides (R-SO₂CN) from sodium sulfinates (R-SO₂Na) by employing potassium cyanide (KCN) and sodium hypochlorite pentahydrate (NaOCl·5H₂O) under weakly acidic conditions. A biphasic medium is essential for suppressing side reactions and enabling broad generality including ¹³C-labeled derivatives. In situ-generated cyanogen chloride (ClCN) was identified experimentally as the key reactive species. The synthetic utility is showcased through the enhanced reactivity of electronically tuned sulfonyl cyanides in useful transformations.