title: Highly efficient synthesis of heterocyclic and alicyclic β2-amino acid derivatives by catalytic asymmetric hydrogenation.
abstract: A valuable class of new heterocyclic and alicyclic prochiral α-aminomethylacrylates has been conveniently synthesized through a three-step transformation involving a Baylis-Hillman reaction, O-acetylation, and a subsequent allylic amination. The corresponding novel β(2)-amino acid derivatives were prepared with excellent enantioselectivities and high yields by catalytic asymmetric hydrogenation using the catalyst rhodium(Et-Duphos) (Et-Duphos = 2',5',2'',5''-tetraethyl-1,2-bis(phospholanyl)benzene)) under mild reaction conditions (up to 99 % ee and S/C = 1000). The influence of the substrate on the enantioselectivity and reactivity is investigated, and the most suitable substrate configuration for the highly efficient enantioselective hydrogenation of β-substituted α-aminomethylacrylates under the Rh-Duphos system is reported. The current protocol provides a very practical, facile, and scalable method for the preparation of heterocyclic and alicyclic β(2)-amino acids and their derivatives.
authors.affiliation: School of Chemistry and Chemical Engineering, Guangdong Engineering Research Center of Chiral Drugs, Sun Yat-sen University, No. 135 Xingangxi Road, Guangzhou 510275, People's Republic of China.
authors.forename: Lanning
authors.initials: L
authors.lastname: Li
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Ke
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhuang
authors.forename: Kun
authors.initials: K
authors.lastname: Duan
authors.forename: Yichun
authors.initials: Y
authors.lastname: Huang
authors.forename: Jiyan
authors.initials: J
authors.lastname: Pang
authors.forename: Liqin
authors.initials: L
authors.lastname: Qiu
mesh_terms: D000107:Acetylation; D000179:Acrylates / Q000737:chemistry; D000586:Amination; D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D006571:Heterocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D006865:Hydrogenation; D012238:Rhodium / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000179:Acrylates; D000596:Amino Acids; D006571:Heterocyclic Compounds; D012238:Rhodium
keywords: amino acids; asymmetric catalysis; heterocycles; hydrogenation; rhodium