Enantioselective Hydrophosphination of Enones with Diphenylphosphine Catalyzed by Bis(imidazoline) NCN Pincer Palladium(II) Complexes

A series of chiral NCN pincer Pd(II) complexes with 1,3-bis(2′-imidazolinyl)phenyl (Phebim) ligands were synthesized via the C–H activation or oxidative addition method. A dinuclear macrocyclic Pd(II) complex was also prepared by reaction of the Phebim-H ligand with PdCl2. All of the new compounds were fully characterized, and X-ray single-crystal structures were obtained for two of the complexes. The Pd(II) complexes were successfully applied to enantioselective hydrophosphination of various enones with diphenylphosphine, providing optically active phosphine derivatives in good yields with enantioselectivities of up to 94% ee.