Study On Preparation And Catalytic Activity Of Supported Chiral Iridium Catalyst

Heterogeneous catalyst can solve the problem of recycling of homogeneouscatalyst, overcame the diiffcult separation of catalyst and product, the environmentalpollution problems, which showed a certain prospect of industrial application, thus itcaused the researchers of great interest. Flower-like mesoporous silica material as anovel mesoporous materials in heterogeneous catalysis reaction in addition to its easyto synthesis and functionalization，and also has a relatively short medium distributedcavity, and the special silicate cavity. With a potential conifnement effect can enhanceits enantiomer stereoselectivity. Periodic mesoporous organosilica (PMO) with largespecific surface area and entrance, controllable pore diameter and ordered poredistribution, high thermodynamic and mechanical stability, also has the very highhydrophobicity, their underlying organic silicon on the inner surface of significantlypromote the transformation of organic functional groups. And functional imidazolephase transfer catalyst can significantly improve in two-phase catalytic systemorganic reaction rate.We use silicon as a carrier of the homogeneous catalyst, organic metal iridiumcomplexes were load type catalyst，and studies and discusses the performance ofcatalyst. This thesis mainly divided into the following two parts:(1) A new method of synthesis of a unique novel flower mesoporous silicamaterials has been developed. Chiral organic metal iridium groups andfunctionalization of lfower silicon self-assembly together to synthesis FMSfunctionalized mesoporous materials, then catalytic a-cyano and a-nitro aromaticketone in the water phase. The catalyst showed the characteristics of the highly active,both reactivity and enantiomer stereoselectivity are higher than that of homogeneouscatalysts. In addition, the Ir is obtained by ionic bonds connected to the material ofheterogeneous catalyst can be recycled use again at least10times, while the activityhas no change. More important is the method used here can be extended to other asymmetric machinist compounds synthesis.(2) A new method, a combination of imidazole phase transfer catalytic andethyl bridge even ordered mesoporous silicone hydrophobic, chiral organiccompounds in solid metal Ir carry over into the mesoporous materials, synthesizedbased on imidazole and organic metal functional of ordered mesoporous silicamaterials synthesized by two kinds of load type of chiral catalysts, the asymmetriccatalytic reduction of a-cyano and a-nitro aromatic ketone and p-ketone ester in thewater phase. Peirodic mesoporous organosilica as a kind of bifunctional catalysts ofheterogeneous catalyst shows its in the water phase ona-cyano and a-nitro aromaticketone asymmetric hydrogen transfer reaction of aryl ketones higher catalyticactivity than homogeneous catalyst and enantiomer stereoselectivity. And afterapplying at least eight times，the activity of catalyst and enantiomerstereoselectivity was nearly unchanged. Developed a kind of more common load ofchiral ligands to organic metal iridium functionalization of ordered mesoporoussilica material and greatly improve the catalytic performance of the method.