title: Enantioselective synthesis of beta2-amino acids via Rh-catalyzed asymmetric hydrogenation with BoPhoz-type ligands: important influence of an N-H proton in the ligand on the enantioselectivity.
abstract: A series of BoPhoz-type ligands were successfully applied in the rhodium-catalyzed asymmetric hydrogenation of a number of beta-substituted or unsubstituted alpha-(phthalimidomethyl)acrylates, affording good to excellent enantioselectivities. The results suggested that the presence of an N-H proton in the BoPhoz backbone could significantly improve the enantioselectivity, and ligand (Sc,Rp)-1d, bearing two CF3-groups in the 3,5-position of the phenyl ring of aminophosphino moiety, showed the highest enantioselectivity.
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Deng
authors.forename: Xiang-Ping
authors.initials: XP
authors.lastname: Hu
authors.forename: Jia-Di
authors.initials: JD
authors.lastname: Huang
authors.forename: Sai-Bo
authors.initials: SB
authors.lastname: Yu
authors.forename: Dao-Yong
authors.initials: DY
authors.lastname: Wang
authors.forename: Zheng-Chao
authors.initials: ZC
authors.lastname: Duan
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Zheng
mesh_terms: D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D063065:Organophosphonates / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D008024:Ligands; D063065:Organophosphonates; D012238:Rhodium