title: Asymmetric synthesis of quaternary alpha- and beta-amino acids and beta-lactams via proline-catalyzed mannich reactions with branched aldehyde donors.
abstract: [reaction: see text] L-Proline-catalyzed direct asymmetric Mannich reactions of N-PMP protected alpha-imino ethyl glyoxylate with various alpha,alpha-disubstituted aldehydes affords quaternary beta-formyl alpha-amino acid derivatives with excellent yields and enantioselectivities. The Mannich products are further converted to the corresponding quaternary alpha- and beta-amino acids and beta-lactams.
authors.affiliation: The Skaggs Institute for Chemical Biology and the Departments of Chemistry and Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
authors.forename: Naidu S
authors.initials: NS
authors.lastname: Chowdari
authors.forename: Jeff T
authors.initials: JT
authors.lastname: Suri
authors.forename: Carlos F
authors.initials: CF
authors.lastname: Barbas
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D000596:Amino Acids / Q000032:analysis / Q000138:chemical synthesis*; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D018360:Crystallography, X-Ray; D008968:Molecular Conformation; D015394:Molecular Structure; D011392:Proline / Q000737:chemistry*; D013237:Stereoisomerism; D047090:beta-Lactams / Q000032:analysis / Q000138:chemical synthesis*
chemical_list: D000447:Aldehydes; D000596:Amino Acids; D047090:beta-Lactams; D011392:Proline