Synthesis And Catalytic Properties Of Porous Materials

As the important components of the porous materials,metal organic frameworks(MOFs)and covalent organic frameworks(COFs)have been applied in heterogeneous catalysis by more and more material chemists,which because of their well-defined pore structure,high specific surface area and satisfactory crystal.In this paper,we respectively investigate the properties of these two materials in catalyzing tandem reaction and asymmetric reaction by means of two strategies,which are in suit self-assembling of MOFs and decorating MNPs or metal-catalysis-site in the framework of MOFs and COFs.?.As the continuation of our group previous work,the heterogeneous catalyst of Au@Cu(II)-MOF was prepared with high performance catalytic activities.By adding Au@Cu(II)-MOF,the substrate of 2,6-Di-tert-butylphenol(1)was oxidized to 2,6-Di-tert-butyl-p-benzoquinone(2)using H2O2 as an oxidizing reagent.Moreover,treating the catalytic reaction mixture with malononitrile,one new product of 2-(3,5-di-tert-butyl-4-hydroxyphenyl)ethane-1,1,2,-tricarbonitrile(3)was obtained.At the meanwhile,one pot tandem reaction of mixing Au@Cu(II)-MOF,(1)and malononitrile also produced the product of(3).However,without loading the catalyst of Au@Cu(II)-MOF,the intermedia of(2)and malononitrile can only form the product of2-(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)ethane-1,1,2,-tricarbonitr ile(4)which is one of the isomer for compound(3).Furthermore,the tautomerization of 3 and 4 was also observed in CH2Cl2 solution driven by triethylamine and acetic acid.?.We synthesized a chiral MOF by the coordination of a chiral BINOL-derived dicarboxylic acid ligand and Zr Cl4 in the solvothermal condition,and the obtained MOF was characterized by XRPD,IR and CD and so on.We used the MOF to catalyze asymmetric cyanosilylation of aromatic aldehydes with a high conversion and stereoselectivity.Furthermore,the MOF can catalyze the reaction at least for five cycles without significant reduction in conversion and stereoselectivity as a typically heterogeneous catalyst.?.A novel chiral COF(CCOF)was synthesized by condensation of enantiopure(R)-BINOL-derived diamine compound with 1,3,5-triformylphloroglucinol in solvothermal condition,followed by the characterization of XRPD,IR and TEM and so on.Then we employed the CCOF for catalyzing asymmetric addition of diethylzinc to aromatic aldehydes with high conversion and stereoselectivity by taking advantage of the Lewis acidic compound,which formed by the coordination of the Ti(Oi Pr)4 with chiral dihydroxy group in the framework.Furthermore,the heterogeneous nature of the CCOF was verified by the fact that it can be recovered and reused for five runs without significant loss of catalytic activity and stereoselectivity.In summary,the study indicates that catalyst obtained by these two strategies can all catalysis the organic reaction efficiently,which also provided valuable experience for the development of more functional heterogeneous catalyst in the later period.