title: Catalytic, enantioselective alkylation of alpha-imino esters: the synthesis of nonnatural alpha-amino acid derivatives.
abstract: Methodology for the practical synthesis of nonnatural amino acids has been developed through the catalytic, asymmetric alkylation of alpha-imino esters and N,O-acetals by enol silanes, ketene acetals, alkenes, and allylsilanes using chiral transition metal-phosphine complexes as catalysts (1-5 mol %). The alkylation products, which are prepared with high enantioselectivity (up to 99% ee) and diastereoselectivity (up to 25:1/anti:syn), are protected nonnatural amino acids that represent potential precursors to natural products and pharmaceuticals. A kinetic analysis of the catalyzed reaction of alkenes with alpha-imino esters is presented to shed light on the mechanism of this reaction.
authors.affiliation: Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
authors.forename: Dana
authors.initials: D
authors.lastname: Ferraris
authors.forename: Brandon
authors.initials: B
authors.lastname: Young
authors.forename: Christopher
authors.initials: C
authors.lastname: Cox
authors.forename: Travis
authors.initials: T
authors.lastname: Dudding
authors.forename: William J
authors.initials: WJ
authors.lastname: Drury
authors.forename: Lev
authors.initials: L
authors.lastname: Ryzhkov
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Taggi
authors.forename: Thomas
authors.initials: T
authors.lastname: Lectka
mesh_terms: D000080:Acetals / Q000737:chemistry; D000478:Alkylation; D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D004952:Esters / Q000737:chemistry; D007098:Imino Acids / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000080:Acetals; D000596:Amino Acids; D004952:Esters; D007098:Imino Acids