Design,synthesis And Catalytic Property Of 3D Chiral BINOL-based Covalent Organic Frameworks

Covalent organic frameworks(COFs)are a class of crystalline porous materials that are composed of light elements(C,H,O,N,etc.)linked by strong covalent bonds.They feature high chemical stability,uniformly distributed pores,and high specific surface areas,which make them competitive candidates for a variety of uses,such as adsorption and separation,organic electronics,energy storage,heterogeneous catalysis,and some other functionalities.In this thesis,guided by the bottom-up approach,optically pure 1,1′-bi-2-naphthol(BINOL)was chosen as the backbone to synthesize two kinds of three-dimensional chiral COFs(CCOFs)by imine condensation reaction.Powder X-ray diffraction,Fourier transform infrared spectroscopy,solid nuclear magnetic resonance(NMR)and nitrogen gas adsorption were utilized to elucidate the structures of these two CCOFs.Their applications in asymmetric catalysis were also investigated.This thesis can be divided into three chapters:In Chapter 1,the research status of COFs,including the linkages and topological structures,was introduced.Moreover,the design,synthesis,and properties of chiral COFs,as well as the existing problems for synthesis of CCOFs were highlighted.Finally,an overview of the meaning and progress for this work was summarized.In Chapter 2,we have designed and synthesized two kinds of chiral BINOL-based monomers.By solvothermal method,these two monomers were reacted with tetra(paminophenyl)methane(TAM)to synthesize two three-dimensional chiral COFs,named COF-YS-1 and COF-YS-2,respectively.According to the powder X-ray diffraction and structural simulation using Material Studio 7.0,the structures of two CCOFs were elucidated.Combined with various characterization methods such as infrared spectroscopy and solid NMR,we have characterized these two CCOFs.These two kinds of chiral COFs could be used as efficient heterogeneous asymmetric catalysts to catalyze asymmetric acetalization reaction,with the ee value of the desired products was up to 97%,and the CCOFs maintained good crystallinity,high catalytic activity,and selectivity after 10 catalytic runs.In contrast,their corresponding monomers didn’t have any asymmetric induction ability.In Chapter 3,a summary and prospect of the work were given.