Studies On Synthesis And Catalytic Applications Of Triphenylphosphine Functionalized Porous Organic Cages

Porous organic cages?POCs?are porous materials built from discrete crystal cage molecules with a micro-mesopore structure.The permanent porosity is both the intrinsic cavities of the cage molecules themselves and the pore channels accumulated through weak interaction between the molecules.These pore channels can penetrate each other under certain conditions.In contrast to three-dimensional network porous frameworks,the porous organic cages are usually solution processable for dissolving in most organic solvents.In addition,the secondary synthons?molecular building blocks?of the POCs can be flexibly modified to introduce specific functional sites for directional synthesis of the desired materials.After ten years of development,a great breakthrough has been made in the design,synthesis and application of porous organic cages.At present,most applications of porous organic cages are still focused on the separation of small molecules and gas adsorption,and there are few reports on catalytic applications.We introduced triphenylphosphine?PPh₃?into porous organic cage to construct a novel cage and realize its catalytic application.Aldehyde-triphenylphosphine and cyclohexylenediamine were assembled into porous organic cage PPh3@cage through dunamic covalent synthesis.After physical structure characterization and further functional modification,the cage was applied in the catalytic carbon dioxide fixation into cyclic carbonates and Cascade Reaction to Bridgehead Methanophosphocines.The first chapter and the second chapter briefly summarized the development of porous organic cages,including synthetic methods and applications.In addition,the reagents and characterization methods used in the experiment are introduced and research idea of this paper are proposed.In the third chapter,Triphenylphosphane-functionalized porous organic cage PPh3@cage was firstly designed and synthesized.Moreover,the structure and porosity were characterized by single crystal X-ray diffraction data?SXRD?and N₂ adsorption experiment.Then Ionic Porous Organic Cage I-PPh3@cage for catalytic carbon dioxide fixation into cyclic carbonates was successfully synthesized.Under co-catalyst Zn Br₂,the activity of the catalyst was comparable to that of the common homogeneous catalyst,and the conversion frequency TOF was up to 800 h^-1.Moreover,the catalyst of I-PPh3@cage could be easily recycled by simple filtration and no significant loss in activity is observed over five cycles.In addition,the scope of the substrates was examined.The desired products were obtained,and the activities are strongly dependent on their structures.In the fourth chapter,the porous organic cage PPh3@cage was further functionally modified to synthesize the gold catalyst Au-PPh3@cage.With the assistance of Ag Sb F₆,Au-PPh3@cage was applied to catalyze the Cascade Reaction to Bridgehead Methanophosphocines and exhibited higher activity than the commonly used Ph₃PAu Cl.In addition,Bis?arylmethyl?alkynylphosphine Oxides with both electron-donating and-withdrawing groups performed equally well,and the desired products were obtained in high to excellent yields.