Formation of Unusual Seven-Membered Heterocycles Incorporating Nitrogen and Sulfur by Intramolecular Conjugate Displacement
journal contributionposted on 15.10.2010, 00:00 by Zhenhua Chen, Derrick L. J. Clive
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 (CF3CO2H), and reaction with CS2. In a modification of this process, when the original nitrogen is substituted in the form PhSCH2CON(Me), an azepine derivative is then generated. The ring closures occur by intramolecular conjugate displacement.