Preparation Of Novel Chiral MOFs And Its Application In Asymmetric Catalysis For Coupling Reaction Of CO₂ With Epoxides

Chiral Metal-Organic Frameworks?CMOFs?are materials of a periodic network structure with chiral characteristics constructed from metal ions and organic ligands.They have the properties of both chiral and MOFs themselves,as a result,they are always used to be a very promising heterogeneous asymmetric catalyst.In this paper,we develop a new approach to the preparation of chiral MOFs through physical adsorption and subsequent postsynthetically modified?PSM?procedures,chiral Salen?Co?can be imprisoned within the cages of MOFs and kept as its free form.Subsequently,the prepared chiral MOFs are firstly applied to the asymmetric coupling reaction of CO₂ with epoxides under the room temperature,and the desired catalytic effect and recycling performance are achieved.In the first chapter,the whole is about the overview and the development of MOFs,especially,we describe the research significance of this paper and research programs in detail.In the second chapter,the heterogeneous asymmetric catalyst named as?R,R?-tBu-Salen?Co?@UMCM-1-NH2-AM3 are prepared by the above method,which are characterized by XRD,1HNMR,ICP,BET,TGA and other instruments.In addition,the prepared catalyst are applied to the coupling reaction of CO₂ with epoxides,which solves the problem that the homogeneous catalyst is not easy to be separated from the product.In the third chapter,IRMOF-3 with strict cubic structure is selected as the precursor of asymmetric heterogeneous catalyst based on the the main research contents came from the second chapter's analysis and summarized.Then,?R,R?-Salen?Co?IRMOF-3-AM1 chiral MOFs catalysts are prepared by the method of?R,R?-tBu-Salen?Co?@UMCM-1-NH2-AM3.The characterization of the catalyst is further confirmed by the addition of solid-state UV-Vis and CD spectra on the basis of XRD,1HNMR,ICP,BET,TGA,which show the expected catalytic effect in the asymmetric catalytic reaction and recycling capacity and solve the separation about the homogeneous catalyst and product,recycling and other problems.