Preparation And Characterization Of Chiral Imidazolinone-supported Catalysts And FDU-PPh₂/Pd(Ⅱ) Catalyzed Suzuki Crossing Coupling Reactions In Aqueous Media

This thesis was focused on two sections. In the first section, we studied immobilization of an enantiopure imidazolidin-4-one on SBA-15 and PEG5000 monomethyl ether. Chiral Imidazolinone-based Ionic Liquids were also designed and synthesized. The catalysts were characterized and the catalytic performance was measured in asymmetric Friedel-Crafts reaction. In the second section, FDU-type mesostructured polymer-supported diphenylphosphine-palladium complex has been developed and applied in Suzuki coupling reaction in aqueous media.From the atom economic point of view, asymmetric catalysis is one of the most important synthetic methods of chiral compounds. Enantioselective organic catalysis is currently the subject of an intense research activity aimed to develop "metal-free" alternatives to established "metal-based" catalytic processes. In many cases, the organocatalysis give rise to extremely high enantioselectivities. While homogeneous processes generally secure best enantioselection, heterogeneous catalysis allows simple product purification, catalyst recovery and recycling. In the first section, we reported the use of SBA-15 and PEG5000 monomethyl ether to readily immobilize a chiral organocatalyst imidazolidin-4-one. The chiral imidazolinone-based ionic liquids were also developed with the L-hydroxy-tyrosine as the starting material. All the catalysts were characterized and applied in asymmetric Friedel-Crafts reaction.In the second section, a novel mesostructured polymer-supported palladium complex (FDU-PPh2/Pd (â…¡)) has been developed. The FDU-PPh2/Pd (â…¡) catalyst was characterized by X-ray diffraction, N2 adsorption-desorption, High resolution transmission electron microscopy. The results indicated that the mesoporous structure of FDU was not affected by the immobilization, however, the pore diameter, pore volume and BET surface area were decreased. The FDU-PPh2/Pd (â…¡) catalyst had higher catalytic activity in Suzuki coupling reaction in aqueous media. Both electron-rich and electron-deficient substrates with arylboronic acids proceeded well and gave high yields for the corresponding products (80-98%) in Suzuki reaction. The FDU-PPh2/Pd (â…¡) catalyst could be easily recovered and reused without significant loss of activity and selectivity for three times in aqueous media and several times in DMF.