Stereoselective synthesis of trans beta-lactams through iridium-catalyzed reductive coupling of imines and acrylates.
[reaction: see text] Iridium-catalyzed reductive coupling of acrylates and imines provides trans beta-lactams with high diastereoselection. The optimal catalyst allows for the synthesis of trans beta-lactams bearing aromatic, alkenyl, and alkynyl side chains. This reaction appears to proceed through a reductive Mannich addition-cyclization mechanism. Examination of substituent effects reveals a linear Hammett correlation for both the N-aryl group on the imine and the aryloxy group on the acrylate, thereby pointing to rate-determining cyclization in the reaction mechanism.
Townes
Jennifer A
JA
Department of Chemistry, Venable and Kenan Laboratories, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA.
Evans
Michael A
MA
Queffelec
Jerome
J
Taylor
Steven J
SJ
Morken
James P
JP
D000179:Acrylates / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D007097:Imines / Q000737:chemistry; D007495:Iridium / Q000737:chemistry; D010084:Oxidation-Reduction; D013237:Stereoisomerism; D047090:beta-Lactams / Q000138:chemical synthesis*
D000179:Acrylates; D007097:Imines; D047090:beta-Lactams; D007495:Iridium