Preparation And Activity Of Supported Chiral Metal Catalysts With Organic - Inorganic Skeleton Mesoporous Silica - Based Materials

Ordered Mesoporous mateirals silicon-bascd have been often used for supportedcatalyst for their excellent properties. Usually, these types of mesoporous materialswith large specific surface area, chemical and physical stability have a series ofadvantages，such as cheap. According to the differences of the skeletal structure,ordered mesoporous silicon-based materials can be divided into inorganic and organicskeleton framework. Inorganic mesoporous silica material refers to those materialswhich only contain inorganic elements within their skeleton while organicmesoporous silica material contain organic/inorganic hybrid elements. Under thereaction condition, the catalysts with different skeletal structure always displaydifferent catalytic performance due to their original peoperities. In addition, the natureof the mesoporous material itself can affect its catalytic performance duirng thecatalytic process.In this paper, we first committed to the synthesis of catalysts with differentskeletal structure, and then check their activity using asymmetric reaction. In thisthesis，we plan to introduce three subjects related to mesoporous silica materialsupported chiral metal catalysts. Firstly, we have successfully synthesized abitfmctional mesoporous inorganic silicon skeleton catalyst and check its activity byasymmetric hydrogen transfer reaction. Secondly, we have prepared three catalystswith different skeletal structure. More important，we have found their difference bythe asymmetric hydrogen transfer reaction. Lastly, we have fabricated a chiralmicro-environment base on the mesoporous silica supporter. The catalytic resultsshow that the micro-environment can improve the stereoselectivity of the reactionproduct. The main work is as follow:(1) In ifrst study, we have successfully prepared a new type of bifunctionalcatalyst based on silica supported inorganic mesoporous material. In this experiment,we have synthesized the catalyst though TEOS as skeletal silica resource and CTABas template agent using copolymerization method. The result of catalytic process indicated that the catalyst can promote the organic reaction rate, especially for the eevalue of products.(2)In second study, we have synthesized three different organic frameworkmesoporous material supported chiral metal rhodium catalyst. We firstly prepared thesupportor by copolymerization method using organic silicon source，and thenimmobilize the transition metal onto the catalyst carrier though coordination bonds ofelectron-rich atoms and rhodium metal. The catalytic results showed thatethylene-bridged catalyst exhibit excellent catalytic performance thancthcnylcnc-bridgcd catalyst, and both them are superior to the phenylene-birdgedcatalyst.(3)In third study, we have successfully fabricated ethylene-bridged hollowsphere supported chiral rhodium metal catalyst. The biggest breakthrough in thissubject is we have successfully constructed a chiral micro-cnvironmcnt which isbenefit to the organic reaction. In this work，we check its activity by thereduction/lactonization reaction of ethyl2-(2-phenylacetyl) beiizoate. The result showthat the chiral micro-environment is very helpful for the enhance of ee values.