The Preparation Of Metal Salen Modified By Chiral Amino Acid And Their Application In The Catalytic Synthesis Of Cyclic Carbonates

In today’s society, low-carbon economy has been the general concerned by everyone, and carbon dioxide as a rich carbon resource, it can be used as raw material in the synthesis of cyclic carbonates, such important compounds, can be used as polar organic solvents, intermediate in organic synthesis and monomer for polycarbonate, and chiral cyclic carbonate also can be prepared in chiral drugs, and so on. In this thesis we mainly study on the kinetic resolution of epoxides, including the following four chapters:Chapter 1:The syntheses of cyclic carbonate are reviewed, in which, the kinetic resolution of epoxides by carbon dioxide is briefly introducted.Chapter 2:The Salen-type ligands and their cobalt Salen catalysts modified by chiral amino acid were designed, synthesized and applied in the kinetic resolution of epoxides by carbon dioxide. Various effects of chiral catalysts, co-catalysts, counterious, reaction temperatures on the asymmetric cycloaddition of racemic epoxides were investigated and discussed. The chiral propylene carbonate was obtained in 48.6% yield and 60.2% ee value at 25℃.Chapter 3:The dialdehyde polymeric of Salen-type ligands and their catalysts modified by chiral amino acid were designed, synthesized which molecular weight reached 17,202, and applied in the asymmetric cycloaddition of epoxides and carbon dioxide. Various effects of chiral catalysts, counterious, co-catalysts, reaction temperatures on the asymmetric cycloaddition of racemic epoxides were investigated and discussed. The catalysts could be readily recovered and reused five times without loss of either activity or enantioselectivity.Chapter 4:The Salen-type ligands modified by the internal olefins of the amino acid were designed and synthesized. It polymerized in two ways:First, heterogeneous catalyst was obtained by self polymerization, and its molecular weight reached 24,218; Second, heterogeneous catalyst was obtained by copolymerization with styrene. Those polymeric catalysts were applied in the asymmetric catalysis.