Indium(I) iodide promoted cleavage of dialkyl disulfides — Application of the Michael addition of thiolate anions to conjugated carbonyl compounds and regioselective ring opening of epoxides

Abstract

Indium(I) iodide promotes cleavage of dialkyl disulfides generating thiolate anions that then undergo facile addition to α,β-unsaturated ketones, aldehydes, carboxylic esters, and nitriles under neutral conditions producing corresponding β-ketosulfides or β-cyanosulfides. This strategy has also been used for the regioselective nucleophilic ring opening of epoxides by thiolate anions in presence of indium(III) chloride producing corresponding β-hydroxyphenyl sulfides. The reactions are in general, very clean, high yielding, and reasonably fast. Thus, simple and convenient procedures for the synthesis of β-ketosulfides or β-cyanosulfides and β-hydroxyalkyl sulfides have been developed using this cleavage reaction.Key words: indium(I) iodide, Michael addition, β-ketosulfide, β-cyanosulfide, epoxide, β-hydroxy sulfide.