title: Facile synthesis of enantioenriched Cγ-tetrasubstituted α-amino acid derivatives via an asymmetric nucleophilic addition/protonation cascade.
abstract: An asymmetric nucleophilic addition/protonation reaction of 3-substituted oxindoles and ethyl 2-phthalimidoacrylate has been described. This strategy can give direct access to C(γ)-tetrasubstituted α-amino acid derivatives bearing 1,3-nonadjacent stereocenters with up to 98% yield, 94:6 dr, and >99% ee. Dual activation is proposed in the transition state, and the opposite enantiomers can be obtained simply by changing cinchonidine-derived catalyst to the cinchonine analogue.
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan, Hubei 430079, China.
authors.forename: Shu-Wen
authors.initials: SW
authors.lastname: Duan
authors.forename: Jing
authors.initials: J
authors.lastname: An
authors.forename: Jia-Rong
authors.initials: JR
authors.lastname: Chen
authors.forename: Wen-Jing
authors.initials: WJ
authors.lastname: Xiao
mesh_terms: D000596:Amino Acids / Q000138:chemical synthesis*; D002244:Carbon / Q000737:chemistry*; D015394:Molecular Structure; D011522:Protons; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D011522:Protons; D002244:Carbon