Synthesis of N-phenyl β-amino acids via iridium-catalyzed asymmetric hydrogenation using mixed monodentate ligands

The iridium-catalyzed asymmetric hydrogenation of N-phenyl-β-dehydroamino acid derivatives was examined using monodentate phosphoramidite ligands. The highest yields and enantioselectivities were obtained using a mixed ligand approach with PipPhos L1 and achiral triphenylphosphine (full conversion, 70% ee).