Indium-Catalyzed Reductive Sulfidation of Esters by Using Thiols: An Approach to the Diverse Synthesis of Sulfides

Article abstract of DOI:10.1002/ejoc.201501559

A new reductive preparation of unsymmetrical sulfides from esters and thiols in the presence of InI₃ and either 1,1,3,3-tetramethyldisiloxane (TMDS) or PhSiH₃ as the reductant was developed. This protocol was applied to not only benzoic acid esters that have a methoxy, methyl, chloro, bromo, iodo, or trifluoromethyl group on the aromatic ring but also aliphatic acid esters with either aromatic or aliphatic thiols. A reaction mechanism is proposed by using Hammett plot results and several control experiments. The reductive preparation of unsymmetrical sulfides from esters and thiols by using InI₃ and either 1,1,3,3-tetramethyldisiloxane (TMDS) or PhSiH₃ was developed. Several mechanistic studies support that the present transformation proceeds through O,S-and S,S-acetals as the reaction intermediates. TMDS = 1,1,3,3-tetramethyldisiloxane, R = aliphatic group.