title: Asymmetric synthesis of α,α-disubstituted amino acids by cycloaddition of (E)-ketonitrones with vinyl ethers.
abstract: Original acyclic (E)-α,α-dialkylketonitrones bearing a chiral auxiliary on their nitrogen atom were synthesized and successfully employed for the asymmetric synthesis of α,α-disubstituted amino acids using regio- and stereocontrolled 1,3-dipolar cycloaddition reactions with vinyl ethers. N-Glycosyl chiral auxiliaries were found to provide excellent exo- and π-facial stereocontrol. The obtained enantiopure cycloadducts were selectively transformed into functional α,α-disubstituted amino acids and related β-peptides through the highly regioselective opening of an intermediate quaternary anhydride.
authors.affiliation: Département de Chimie Moléculaire (SERCO) UMR 5250, ICMG FR-2607, CNRS-Université Joseph Fourier , BP 53, 38041 Grenoble Cedex 09, France.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Zhang
authors.forename: Pascale
authors.initials: P
authors.lastname: Cividino
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Poisson
authors.forename: Pavlo
authors.initials: P
authors.lastname: Shpak-Kraievskyi
authors.forename: Mathieu Y
authors.initials: MY
authors.lastname: Laurent
authors.forename: Arnaud
authors.initials: A
authors.lastname: Martel
authors.forename: Gilles
authors.initials: G
authors.lastname: Dujardin
authors.forename: Sandrine
authors.initials: S
authors.lastname: Py
mesh_terms: D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D061565:Cycloaddition Reaction; D015394:Molecular Structure; D013237:Stereoisomerism; D014753:Vinyl Compounds / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D014753:Vinyl Compounds; C100195:vinyl ether