Enantioselective Synthesis of β-AryI-γ-amino Acid Derivatives via Cu-Catalyzed Asymmetric 1,4-Reductions of γ-Phthalimido-Substituted αβ-Unsaturated Carboxylic Acid Esters.

A series of chiral β-aryl-substituted γ-amino butyric acid derivatives were synthesized in good enantioselectivities via the Cu-catalyzed asymmetric conjugate reduction of γ-phthalimido-α,β-unsaturated carboxylic acid esters using Cu(OAc)2·H2O as a catalyst precursor, (S)-BINAP as a ligand, PMHS as a hydride source, and t-BuOH as an additive. The methodology has been applied successfully to the enantioselective synthesis of a chiral pharmaceutical, (R)-baclofen. [ABSTRACT FROM AUTHOR]