Hydrosilylation Of Olefins Catalyzed By Titanium And Nickel Complexes

The hydrosilylation reaction is a main method for preparing various silicon monomers and polymers,due to their advantages of mild conditions,simple operation,and less by-products.The most commonly catalysts used in hydrosilylation reactions are precious metal catalysts such as Speier catalysts,Karstedt catalysts,and Wilkinson catalysts.Although these catalysts exhibite high catalytic activity and good chemical selectivity,they are expensive and difficult to recycle.As is known,the non-noble transition metals such as iron,cobalt,nickel,titanium,etc.are regarded as the catalysts with high activity.In this paper,simple titanium compounds（Cp₂TiCl₂,Ti（OEt）₄,KO^tBu）and nickel complexes are used to catalyze the hydrosilylation of olefins with hydrosilanes in the present of additives or phosphorus ligands.The main methods are as follows:（1）Cp₂TiCl₂ catalyzed hydrosilylations of linear olefins with hydrosilanes in the present of additions such as metal strontium（Sm）or LiAlH₄;tetraethyl titanate Ti（OEt）₄ catalyzed hydrosilylations of different olefins and hydrosilanes.（2）A series of commercial available or prepared phosphorus ligands were used.These ligands cooperated with simple nickel compounds can catalyze the reaction of different olefins with hydrosilanes,and the new nickel complexes synthesized were established by single-crystal X-ray diffraction.The conditions of these catalytic systems such as different amount and ratio of catalysts,reaction time and reaction temperature for the hydrosilylation of olefins and hydrosilanes were investigated.The results show that the catalyst designed in this paper can efficiently catalyze the reaction of olefins with second hydrosilanes（for example:Ph₂SiH₂,PhMeSiH₂）,and excellent selectivities were obtained.Expecially phosphorus-nickel complexes synthesized in this paper,100%β-adduction were obtained which was potential application in industry.