Synfacts 2011(2): 0213-0213  
DOI: 10.1055/s-0030-1259351
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart ˙ New York

NHC-Catalyzed Intramolecular Redox Lactamization

Contributor(s): Benjamin List, Lars Ratjen
K. Thai, L. Wang, T. Dudding, F. Bilodeau, M. Gravel*
University of Saskatchewan, Saskatoon, Brock University, St. Catharines, and Boehringer Ingelheim, Laval, Canada
Further Information

Publication History

Publication Date:
19 January 2011 (online)

Significance

An intramolecular N-heterocyclic carbene (NHC) precatalyst 1 mediated lactamization of cyclic α-amino aldehydes is reported. The catalytic cycle proceeds via the Breslow intermediate, which enables a ring opening (A), tautomerization (B), cyclization (C) sequence. Furthermore, the conjugate acid of the external base, which is added to deprotonate the catalyst precursor 1, is assumed to further trigger the ring-opening process of the intermediate by hydrogen-bonding ­assistance.