Preparation Of Supported Chiral Rhodium And Iridium Catalysts And Their Catalytic Performance

Under the call of environmental protection and green chemistry, We have made great development in immobilized catalysts. The immobilized catalysts are easier to recycle than homogeneous catalysts, which make the catalysts and the products are easy to separated, so they are environment friendly catalysts.Among the supports of the immobilized catalysts, periodic mesoporous organosilica material(PMO) have been widely concerned in academic world, because they have large surface area, controllable pore size, high thermodynamic and mechanical stability and unique hydrophobic.However, immobilized catalysts also have some shortcomings, such as awful catalitic reactivity and bad recycling. So developing new immobilized catalysts has become the hotspot of chemical research.In this paper, we prepared three immobilized catalysts with different organnic skeletons, and then characterized them, and finally checked their catalytic activity using asymmetric reaction. In addition,we created a new recycle method of homogeneous catalysts.(1) In this study, we prepared three immobilized catalysts with different organnic skeletons using three kinds of organosilane by copolymerization method. Experimental results indicated that ethylene-bridged catalyst exhibit excellent catalytic performance than ethenylene-bridged catalyst,and both them are superior to thephenylene--bridged catalyst. We also devled into the reason of this phenomenon.(2) In this study, we synthesized ethenylene-bridged catalyst which loaded chirality iridium catalyst. And then check their catalitic activity using asymmetric reduction of α-substituted aromatic ketone. This catalyst has unique hydrophobic, which improved the catalytic activity of the homogeneous catalysts.(3) In this study, we synthesized pyrene modified chirality iridium catalyst. And then check their catalitic activity using asymmetric reduction of α-substituted aromatic ketone. The catalytic results showed tha the catalyst can be released by magnetic carbon nanoube under high tempreture and be collected by magnetic carbon nanoube under low tempreture.