Iodine Promoted Regioselective α-Sulfenylation of Carbonyl Compounds using Dimethyl Sulfoxide as an Oxidant

A metal-free regioselective sulfenylation of the alpha-CH3 group of ketones has been achieved in the presence of the alpha-CH2 or alpha-CH group using the cross dehydrogenative (CDC) strategy. Aldehydes also exhibit good selectivity forming the corresponding alpha-sulfenylated products. This efficient sulfenylation of ketones or aldehydes with thiones or heterocyclic thiols utilizes dimethyl sulfoxide (DMSO) as an oxidant in the presence of iodine. This eco-friendly method uses readily available and inexpensive I, and DMSO. The application of this methodology has been demonstrated by synthesizing precursors for Julia-Kocienski olefination intermediates.