Functionalized Phosphine Ligands In The Application Of Hydrosilylation

Hydrosilylation is an important reaction for the formation of Si-C and Si-O bond in organosilicon chemistry.It has many advantages,such as,mild reaction conditions,easy to operate,less by-products and high yield.The hydrosilylation of unsaturated alkene is an effective method for the preparation of alkyl?alkoxy?silane.In the process of homogeneous catalysis reaction,apart from the effect of metal center,the ligands used also play an important role for thereaction.Oneof themostimportantligandsinahomogeneous transition-metal-catalyzed reaction is phosphine ligands.Because the steric and electronic effects of the phosphine ligands are especially important to transition-metal-catalyzed reactions.Therefore,in order to realize highly catalytic activity and selectivity,design and modification of the phosphine ligands have been extensively investigated.This paper is divided into two aspects:for one thing,preparation of a series of acylphosphine ligands and then use it with transition-metal rhodium compounds to form Rh-P catalytic system to catalytize the hydrosilylation of styrene and triethoxysilane.And the effects of reaction time,reaction temperature and acylphosphine ligands with different substituents on the hydrosilylation of styrene and triethoxysilane were investigated.It was found that the selectivity of the reaction was greatly improved by the use of acylphosphine ligands.For another,the 2-diphenylphosphine Polyethylene-glycol functionalized imidazolium ligand was synthesized,and the ligand prepared was used to complexed with transition metal RhCl₃ to form Rh-P catalytic system,and the catalytic properties of this catalytic system for the hydrosilylation of styrene and triethoxysilane was investigated.It was found that the molecular weight of ligand,the length of the polyether chain and the amount of ligand influence the conversion and the selectivity of the reaction.