NHC-Catalyzed Intramolecular Redox Amidation for the Synthesis of Functionalized Lactams
Karen Thai, Li Wang, Travis Dudding, François Bilodeau and Michel Gravel*
*Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, Canada, Department of Chemistry, Brock University, St. Catharines, ON L2S 3A1 Canada, Email: michel.gravelusask.ca
K. Thai, L. Wang, T. Dudding, F. Bilodeau, M. Gravel, Org. Lett., 2010, 12, 5708-5711.
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A very efficient NHC-catalyzed ring expansion reaction cleanly furnishes five- and six-membered N-Ts and N-Bn lactams, without the need for further purification. The stoichiometric base is responsible for deprotonation of the triazolium precatalyst and activation of the nitrogen leaving group through hydrogen bonding.
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