Ene-yne unsaturated compounds as accelerators for hydrosilation

#The present invention is a hydrosilation process where a silicon hydride is reacted with an unsaturated reactant in the presence of a platinum catalyst and an accelerator selected from a group consisting of ene-yne unsaturated compounds. The accelerators are especially useful for facilitating the hydrosilation of unsaturated reactants where the unsaturation is in the internal portion of the reactant's structure, for example, as in cyclopentene and cyclohexene. The accelerators are believed to be effective in the presence or absence of oxygen.

#It is known in the art to produce organosilicon compounds by reacting a silicon hydride containing compound with an unsaturated organic compound in the presence of a catalyst. This reaction is typically referred to as hydrosilation or hydrosilylation. Typically the catalyst is platinum metal on a support, a platinum compound usually in a solvent, or a platinum complex.

#In Speier et al., U.S. Pat. No. 2,823,218, a method for the production of organosilicon compounds by reacting an Si-H with a compound containing aliphatic carbon atoms linked by multiple bonds in the presence of chloroplatinic acid is taught. Lamoreaux, U.S. Pat. No. 3,220,972, teaches a similar process, however the catalyst is a reaction product of chloroplatinic acid.

#The present invention is a hydrosilation process where a silicon hydride is reacted with an unsaturated reactant in the presence of a platinum catalyst and a novel accelerator. The hydrosilation process comprises: contacting

#(A) a silicon hydride described by formula

#R.sup.1.sub.a H.sub.b SiX.sub.4-a-b (B 1)