Hydrosilylation Of Ketones By Lithium And Zinc Catalyst

Hydrosilylation can produce a variety of difficult to synthesis in other way of organic silicone monomers or polymers containing functional groups. The species are numerous, the performance is good. They has been widely used in agricultural industry, emerging technology, national defense military industry and other fields. Hydrosilylation is one of the most useful catalytic methods for the synthesis of enantiomerically enriched secondary alcohols from ketones. The hydrosilylation presents the advantages of simplicity of the procedure combined with high product purity, the use of inexpensive silanes, etc. Since Sommer found the hydrosilylationin the 1950 s, it has attracted a lot of attention in the industrial production and scientific research. In recent years, one of the main targets of studies on hydrosilylation is the development of catalytic systems that would comply with the criteria of high efficiency, high stability, low cost, and environmentally friendly. Catalyst from the early Ru, Rh, Ir to the Ni, Fe, Zinc, Co and other metals. Following the related literature reported more and more, it has become a research hotspot because of Ni, Fe, zinc, Co catalysts’advantages such as low cost, environmental stability, high catalytic activity. In this context, we studied the hydrosilylationof ketones catalzyed by the choice of the metal catalyst, show the following aspectson the basis of previous work.1) Preparation of chitosan schiff base ligands, with natural polymer chitosan as raw materials, then added diethyl zinc to obtain the catalyst Following catalytic acetophenone hydrosilylation reaction with triethoxysilane, with tetrahydrofuran as solvent, Hydrolysising of silicon ether, then obtain the secondary alcohol. At room temperature, reacted for 17 hours, it indicates that the conversion of acetophenone is over 99%.2) With lithium metal as catalyst, catalytic acetophenone with triethoxysilane hydrosilylation reaction directly. Hydrolysising of silicon ether, then obtain the secondary alcohol. It shows that the conversion of acetophenone is over 99%.This two kinds of catalytic system have the advantages of cheap, environmental protection, wide applicable scope and easy operation. The catalytic system has huge potential value, The research of this topic has some inspiration role in the hydrosilylation of ketones catalyzed by metal.