Formation of unusual seven-membered heterocycles incorporating nitrogen and sulfur by intramolecular conjugate displacement.
Baylis-Hillman alcohols derived from methyl acrylate or acrylonitrile and carrying an N-Boc group β to the hydroxyl (CH(OH)CHNBoc) can be converted into unusual seven-membered heterocycles containing both nitrogen and sulfur by O-acylation (AcCl or EtOCOCl), N-deprotection (CF(3)CO(2)H), and reaction with CS(2). In a modification of this process, when the original nitrogen is substituted in the form PhSCH(2)CON(Me), an azepine derivative is then generated. The ring closures occur by intramolecular conjugate displacement.
Chen
Zhenhua
Z
Chemistry Department, University of Alberta, Edmonton, Alberta T6G 2G2, Canada.
Clive
Derrick L J
DL