Allenylphosphine Oxides And The Hydrosilylation Of Olefins Catalyzed By MOFs

In recent years,metal-organic framework materials(MOFs)have developed rapidly and have become popular targets for scientists.Due to its high specific surface area,rich topology,variable pore size,etc.,the material has potential applications in gas adsorption and separation,drug delivery,optics,electricity and catalysis.Especially in the field of catalysis,the development is particularly rapid,and its high catalytic activity and green recyclability are favored by scientists.MOFs can not only act as a highly efficient catalyst,but also act as a carrier to load various functional materials for catalysis.Based on this,the research work of this thesis is mainly based on the coupling reaction and hydrosilylation reaction of MOFs with two different catalytic active sites.The paper is divided into the following two parts:The Pd@UiO composite was prepared by the two-solvent reduction method with the UiO series metal-organic framework as the precursor.The catalysts were characterized by TEM,XRD,ICP-Ms,BET and TG.The results show that the Pd nanoparticles can be uniformly dispersed in the pores of MOFs.The catalyst can catalyze the coupling reaction of allenylphosphine oxides ether with an alkyne,and efficiently construct a phosphine-substituted conjugated alkyne compound.During the experiment,the solvent,base,catalyst,temperature and reaction time were investigated,and the optimal conditions were obtained.The possible reaction mechanism was proposed:the substrate diffused into the cavity of MOFs and adsorbed on palladium nanometer.On the surface of the particles,an allyl palladium species and a C(sp3)-O(Ar)bond are subsequently cleaved.With the help of a base,metal insertion,metallization,and ?-hydrogen reduction with an alkyne are carried out to finally obtain a target product.The purified product was isolated,and the compound was characterized by 1H-NMR,13C-NMR,31P-NMR,HR-MS,etc.,and 26 new compounds which were not reported in the literature were synthesized.The single crystal structure of one of the compounds confirms the spatial conformation of the cross-conjugate of two double bonds with one triple bond.2.Ni-MOF was synthesized by a hydrothermal synthesis method using nitrogen-containing tricarboxylic acid ligands:N-tribenzoic acid and transition metal Ni(?)by adjusting the reaction time,reaction temperature and reaction solvent.The structure was characterized by X-ray single crystal diffraction.The results show that Ni-MOF belongs to the triclinic P-1 space group and its molecular formula is C42H34N2Ni4O18.Each of the asymmetric units includes four Ni(?)ions and two intact N-tribenzoic acid ligands.All four Ni(?)ions exhibit a six-coordinated regular octahedral configuration.It has a relatively complete three-dimensional structure.The catalyst can realize the hydrosilylation reaction of styrene and phenylsilane.During the experiment,the solvent,base,temperature and reaction time were investigated,and the optimal conditions were obtained.Under the catalytic comparison of Ni-BDC-MOF synthesized with terephthalic acid as ligand,it is further proved that Ni-MOF has high catalytic activity for hydrosilation.