Quinine-Derived Imidazolidin-2-imine Ligands: Synthesis, Coordination Chemistry, and Application in Catalytic Transfer Hydrogenation

Two new optically active bidentate N N ligands, DMIQCI (3a) and DMIQCD (3b), containing a quinuclidine core and an imidazolidin-2 imine unit were synthesized The re-tenon of these ligands with [(eta(5) C5Me5)RuCl](4) afforded the brick-red ruthenium(II) complexes [(eta(5) C5Me5)Ru(DMIQCI)Cl] (4) and [(eta(5) C5Me5)Ru(DMIQCD)Cl] (5), which were used is catalysts in the transfer hydrogenation of acetophenone in boiling 2 propanol The reactions of 3a and 3b with [(COD)PdCl2] (COD = 1,5 cycloocta diene) and with [(DME)NiBr2] (DME = 1 2 dimethoxyethane) afforded the square planar palladium(II) complexes [(DMIQCl)PdCl2] (7) and [(DMIQCD)PdCl2] (8) or the tetrahedral nickel(11) complexes [(DMIQCI)NiBr2] (9) and [(DMIQGD)NiBr2] (10) respectively The X ray crystal structures of 4, 7, 9 THF and 10 are reported