Investigating the use of a thioketene methodology for heterocyclic ring formation
University of New Brunswick
Thioamides are important and useful functional groups in organic synthesis, especially as building blocks for the construction of compounds containing N and S that possess pharmacological properties. A convenient and general method for the preparation of thiolactams using a thioketene strategy as an alternative route for heterocyclic formation has been examined. Amino-alkynes, which were easily synthesized in two steps, acted as bifunctional substrates for intramolecular reactions. Thioketenes were generated at low temperature by protonation, silylation or alkylation of amino-alkynyl thiolates. The in situ generated thioketenes were then trapped with different amines through intramolecular reactions to produce thiolactams in various yields. This is the first report of the intramolecular trapping of thioketenes with amines to produce thiolactams.