Synthesis, Characterization Of Transition Metal Complexes Of Chiral Bis(Oxazoline) And Schiff Bases And Its Asymmetric Catalytic Properties

The development of efficient asymmetric synthesizing methods has been one of the most important and most challenging fields in organic chemistry, asymmetric synthesizing methods include substrate-selective and chiral catalyst-selective asymmetric synthesis, moreover, the most interesting and challenging one is catalyst-selective asymmetric synthesis. Investigations indicate that metal complexes of chiral schiff-bases, chiral half-pyrrocorphin, chiral bis(oxazoline) ligands have excellent catalytic effects, which have been applied prevalently in recent years.Especially in the past 30 years, asymmetric cyclopropanation reactions using chiral transition metal complexes as catalysts have gained more and more attention. These products have played an important action in pesticides and pharmic fields, and so on. Thus, we synthesize chiral 2,6-bis(oxazoline)pyridine and asymmetric chiral schiff-base ligands and their transition metal complexes, which are used as enantio-selective catalysts in asymmetric cyclopropanation reactions of diazoacetate and 1,1-diphenyl ethylene. Our main works are as following:1. Two chiral C2-symmetric 2,6-bis(oxazoline)pyridine ligands and their nickel(II), zinc(II), manganese(II), iron(III),copper(II) and cobalt(II) complexes were synthesized using Schlenk and cannula techniques, and characterized with elemental analysis, IR spectroscopy, also some of them were characterized with thermal analysis and single crystal X-ray diffraction.2. Six chiral asymmetric schiff-base ligands from chiral aminol and corresponding aldehydes and their complexes with transition metal salts were synthesized and characterized with elemental analysis, IR spectroscopy, also some of them were characterized with thermal analysis and single crystal X-ray diffraction.3. Chiral ligands mentioned above and their complexes with acetate copper were used as enantio-selective catalysts in asymmetric cyclopropanation reactions of diazoacetate and 1,1-diphenyl ethylene. Investigations indicate that all of them reveal certain optical-selective capability, but chiral C2-symmetric 2,6-bis(oxazoline)pyridine ligands show better catalytic capability than chiralasymmetric schifF-base ligands.