Conversion of Amides and Lactams to Thioamides and Thiolactams Using Hexamethyldisilathiane

Article abstract of DOI:10.1021/jo00081a011

Amides and lactams were converted to their corresponding thioamides and thiolactams employing a new protocol using hexamethyldisilathiane (TMS2S).Oxophilic promoters were employed to generate Vilsmeier-type intermediates, the most efficient reagents being phosphorus oxychloride, triphosgene, and oxalyl chloride.Thionation of intermediate chloro iminium ions was accomplished in situ with TMS2S.Yields were good to excellent for secondary and tertiary amides and lactams while yields for primary systems were poor.