Enantioselective Staudinger Synthesis of β-Lactams Catalyzed by a Planar-Chiral Nucleophile
Brian L. Hodous and Gregory C. Fu*
*Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, Email: gcfmit.edu
B. L. Hodous, G. C. Fu, J. Am. Chem. Soc., 2002, 124, 1578-1579.
The Staudinger synthesis, an overall [2 + 2] cycloaddition of a ketene with an imine, provides a nicely convergent route to biologically and synthetically interesting β-lactams. A planar-chiral derivative of 4-(pyrrolidino)pyridine serves as a very effective enantioselective catalyst coupling a range of symmetrical and unsymmetrical ketenes with various imines with very good stereoselection and yield.
see article for more examples
Catalytic Asymmetric Staudinger Reactions to Form β-Lactams: An Unanticipated Dependence of Diastereoselectivity on the Choice of the Nitrogen Substituent
E. C. Lee, B. L. Hodous, E. Bergin, C. Shih, G. C. Fu, J. Am. Chem. Soc., 2005, 127, 11586-11587.
Staudinger Synthesis, β-Lactams