Dc. Smith et al., CONVERSION OF AMIDES AND LACTAMS TO THIOAMIDES AND THIOLACTAMS USING HEXAMETHYLDISILATHIANE, Journal of organic chemistry, 59(2), 1994, pp. 348-354
Amides and lactams were converted to their corresponding thioamides an
d thiolactams employing a new protocol using hexamethyldisilathiane (T
MS(2)S). Oxophilic promoters were employed to generate Vilsmeier-type
intermediates, the most efficient reagents being phosphorus oxychlorid
e, triphosgene, and oxalyl chloride. Thionation of intermediate chloro
iminium ions was accomplished in situ with TMS(2)S. Yields were good
to excellent for secondary and tertiary amides and lactams while yield
s for primary systems were poor.