The Preparation Of Carboxylates On Functionalized Ionic Liquid In Co-catalyzing Hydrosilylation Reaction

Hydrosilylation is an important reaction for silicone chemistry. Hydrosilylation is a major method for preparing silicone monomers and silicone polymer. Hydrosilylation has many advantages, including a mild reaction, simple operation, less by-product, high product yield and so on. With the deepening of hydrosilylation, the applicability of hydrosilylation is broader than others and richer product.Catalyst almost accompanied by the development of the reaction, and is the key of hydrosilylation. The classic catalysts are Speier catalyst, Karstedt catalyst, Wilkinson catalyst and so on, they are precious metal catalysts. Although they have high activity and selectivity, they are expensive, difficult for recovery. These shortcomings have hindered the development of catalysts.Currently, the catalyst was composed of transition metal and ligand. In transition metals, precious metals (platinum, rhodium, etc.) generally have good catalytic activity. Compared with precious metals, non-precious metal catalytic effect is poor and the scope of application is very narrow. The main catalyst ligands are phosphine-containing ligand or nitrogen-containing ligand. Ligand and transition metal influence each other, can be more stable for the catalyst and enhance the catalytic effect significantly.Based on previous research, two aspects of the work are developed. On the one hand, associated with the noble metal (Pt and Rh) and the non-precious metal (Ca, Mg, Ni, Cu, Fe, Zn), precious metal played a catalytic center and non-precious metal performanced the advantages of itself assist the catalytic reaction. At the same time, nitrogen-containing ligands is introduced into the catalyst, a series of carboxylic acid functionalized ionic liquids are prepared. Thus they form catalytic system formation of ligand and double metal, that catalytic hydrosilylation reaction. On the basis of the Karstedt and [Rh (COD) Cl]2, the work of this article further enhance the catalytic activity, improve the selectivity of the target product, reduce the amount of precious metals and the by-products generated. Experimental results show that, the designed and synthesized catalytic system of double metal can effectively catalyze olefins with triethoxysilane in hydrosilylation. Compared with the conventional precious metal catalyst, which enables catalytic activity and selectivity have improved a lot, and the amount of the precious metal can be further reduced.On the other hand, some additives, which can increase the catalytic activity and selectivity, were added to rhodium-catalyzed hydrosilylation. To explore its impact on hydrosilylation reactions, the hydrosilylation reaction that RuCl3 catalyze olefins with triethoxysilane was added some phosphine ligands. The results show that adding a small amount of the phosphine ligand can improve the catalytic activity and selectivity.