title: The development of the first catalyzed reaction of ketenes and imines: catalytic, asymmetric synthesis of beta-lactams.
abstract: We report practical methodology for the catalytic, asymmetric synthesis of beta-lactams resulting from the development of a catalyzed reaction of ketenes (or their derived zwitterionic enolates) and imines. The products of these asymmetric reactions can serve as precursors to a number of enzyme inhibitors and drug candidates as well as valuable synthetic intermediates. We present a detailed study of the mechanism of the beta-lactam forming reaction with proton sponge as the stoichiometric base, including kinetics and isotopic labeling studies. Stereochemical models based on molecular mechanics (MM) calculations are also presented to account for the observed stereoregular sense of induction in our reactions and to provide a guidepost for the design of other catalyst systems.
authors.affiliation: Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Taggi
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Hafez
authors.forename: Harald
authors.initials: H
authors.lastname: Wack
authors.forename: Brandon
authors.initials: B
authors.lastname: Young
authors.forename: Dana
authors.initials: D
authors.lastname: Ferraris
authors.forename: Thomas
authors.initials: T
authors.lastname: Lectka
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis*; D002384:Catalysis; D005030:Ethylenes / Q000737:chemistry*; D007097:Imines / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D008958:Models, Molecular; D047090:beta-Lactams / Q000138:chemical synthesis*
chemical_list: D000900:Anti-Bacterial Agents; D005030:Ethylenes; D007097:Imines; D007659:Ketones; D047090:beta-Lactams; C008223:ketene