Preparation Of Porous Material Containing Phosphine And Its Application In Silylation Of Halogenated Aromatic Hydrocarbons

Arylsilanes have low toxicity,good stability,and excellent physicochemical properties,and have been used in many fields such as organic synthesis,new drug development,and special material preparation.Currently,organometallic reagent methods and transition metal catalyzed silylation of C-H and C-X bonds have been developed to synthesize arylsilanes.Compared to the former,transition metal catalyzed silylation has the characteristics of higher atomic economy.However,currently developed catalysts are still dominated by homogeneous catalysts of noble metals such as palladium,platinum,and rhodium.The recovery and reuse of catalysts during the reaction process is a difficult problem to be solved.With the deepening of the research,it is the future development trend to realize the heterogeneous of homogeneous catalysts.The biggest difficulty lies in how to make the heterogeneous catalytic system have the same catalytic activity as the homogeneous catalytic system.In recent years,porous phosphine containing organic polymers（P-POPs）with large porosity,high specific surface area,good stability,and high controllability have been successfully used as carrier materials in transition metal organic reaction systems,with catalytic performance equivalent to or even better than homogeneous catalysts.This has aroused our great interest.Based on this,this thesis has purposefully designed and prepared a variety of functionalized porous phosphine containing polymers,and investigated their applications in palladium catalyzed silylation of iodinated aromatic hydrocarbons with hydrosilanes.Firstly,a series of novel functionalized phosphine containing porous organic polymers（P-POPs）were prepared by the polymerization of tris（4-vinyl）triphenylphosphine（3Vi-PPh₃）with eleven functionalized olefin monomers via alkene polymerization initiated by a free radical initiator（AIBN）.The effects of the amount of free radical initiator,the ratio of different olefin monomers,and the combination on the morphology,porosity,specific surface area,and thermal stability of the polymer were systematically investigated using two or three component phosphine containing porous polymers composed of 3Vi-PPh₃and four different functionalized olefins（F-Vi）,namely octavinyl POSS,glycidyl methacrylate（GMA）,allyl cyanoacetate（ACA）,and p-divinylbenzene（DVB）.It was found that in a two component system,the specific surface areas of ACA and GMA were larger than those of DVB and POSS,and the optimal content of functionalized olefins was Vi-PPh₃:F-Vi=1:3.An increase in the proportion of functionalized olefins would significantly decrease the specific surface area of the polymer;When POSS monomer is introduced into a three component system,the change in POSS content compared to the adjustment ability of surface area is not significant,but it is beneficial to improve the thermal stability of the polymer.We use the palladium catalyzed silicon carbon coupling reaction of iodoaromatic hydrocarbons with trialkylhydrosilane as a model reaction,the catalytic performance（chemical selectivity,recyclability）of a series of phosphonic porous polymer supported Pd catalysts prepared by copolymerization of more than ten olefin monomers with functional groups such as cyano,ester,epoxy,formamide,and pyrrolidine with 3Vi-PPh₃was evaluated and screened,The preferred functionalized olefins were glycidyl methacrylate（GMA）and allyl cyanoacetate（ACA）,and their optimal ratios were obtained.The study found that the prepared catalyst can be recycled for three times,exhibiting extremely excellent catalytic activity in the third cycle,outperforming the homogeneous catalytic system in terms of palladium content and chemical selectivity.The reaction mechanism deserves further exploration.In summary,this thesis has prepared a series of functionalized phosphine containing porous polymers,and explored the application prospects of these support materials in palladium catalyzed silicon carbon coupling reactions of halogenated aromatic hydrocarbons using the silicon carbon coupling reaction of iodinated aromatic hydrocarbons and trialkyl hydrosilanes as a model reaction.It lays a good foundation for the further development of transition metal catalyzed silylation of halogenated aromatic hydrocarbons towards highly active heterogeneous catalysts.