title: Catalytic asymmetric Staudinger reactions to form beta-lactams: an unanticipated dependence of diastereoselectivity on the choice of the nitrogen substituent.
abstract: There are relatively few methods for the catalytic asymmetric synthesis of beta-lactams, and those that have been reported are generally cis selective. This communication describes the first catalytic enantioselective Staudinger reactions that preferentially furnish trans beta-lactams (trans = relationship of Ph to R1). The key to this method is the use of an N-triflyl protecting group for the imine. Along with serving as interesting targets in their own right, N-triflyl beta-lactams readily react with nucleophiles to generate useful families of compounds, such as gamma-amino alcohols and beta-amino acids.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Elaine C
authors.initials: EC
authors.lastname: Lee
authors.forename: Brian L
authors.initials: BL
authors.lastname: Hodous
authors.forename: Enda
authors.initials: E
authors.lastname: Bergin
authors.forename: Crystal
authors.initials: C
authors.lastname: Shih
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Fu
mesh_terms: D002384:Catalysis; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*; D010084:Oxidation-Reduction; D013237:Stereoisomerism; D047090:beta-Lactams / Q000138:chemical synthesis*
chemical_list: D047090:beta-Lactams; D009584:Nitrogen