Practical Rh(I)-Catalyzed Asymmetric Hydrogenation of β-(Acylamino)acrylates Using a New Unsymmetrical Hybrid Ferrocenylphosphine−Phosphoramidite Ligand: Crucial Influence of an N−H Proton in the Ligand
摘要:
Excellent enantioselectivities and high turnovers (S/C = 5000) were achieved in the Rh(l)-catalyzed asymmetric hydrogenation of both beta-aryl-and beta-alkyl-beta-(acylamino)acrylates with a new unsymmetrical hybrid ferrocenylphosphine-phosphoramidite ligand, and the presence of an N-H proton in the ligand was demonstrated to have a crucial role in the enantioselectivity.
Chiral 1-phenylethylamine-derived phosphine-phosphoramidite ligands for highly enantioselective Rh-catalyzed hydrogenation of β-(acylamino)acrylates: significant effect of substituents on 3,3′-positions of binaphthyl moiety
A series of new chiral phosphine-phosphoramidite ligands with a 3,3′-substituted binaphthyl moiety were prepared from 1-phenylethylamine, and successfully applied in the Rh-catalyzed asymmetrichydrogenation of β-(acylamino)acrylates. The research disclosed that the substituents on the 3,3′-positions of binaphthyl moiety significantly influenced the enantioselectivity.