title: Catalytic α-allylation of unprotected amino acid esters.
abstract: Catalytic α-allylation of unprotected amino acid esters to produce α-quaternary α-allyl amino acid esters is reported. Catalytic loadings of picolinaldehyde and Ni(II) salts induce preferential reactivity at the enolizable α-carbon of amino acid esters over the free nitrogen with electrophilic palladium π-allyl complexes. Fourteen examples are given. Additionally, the use of chiral ligands to access enantioenriched α-quaternary amino acid esters from racemic precursors is demonstrated by the enantioselective synthesis of α-allyl phenylalanine methyl ester from racemic phenylalanine methyl ester.
authors.affiliation: Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405-7102, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Fang
authors.forename: Mani Raj
authors.initials: MR
authors.lastname: Chaulagain
authors.forename: Zachary D
authors.initials: ZD
authors.lastname: Aron
mesh_terms: D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry*; D002384:Catalysis; D004952:Esters; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D004952:Esters; D010165:Palladium