Catalytic hydrosilylation using an immobilized Co-terpyridine complex activated by inorganic salts and its application in a flow reactor

Abstract

The activation of a dibromo Co-terpyridine complex immobilized on a stationary phase (Co(tpy)Br₂@SiO₂) as a hydrosilylation catalyst was investigated. Inorganic salts that are sparingly soluble in an organic solvent were examined as activators, and K₂CO₃ was found to show advantages in activator ability, stability, cost, and ease of handling. Catalytic hydrosilylation using Co(tpy)Br₂@SiO₂ activated by K₂CO₃ afforded the products in good yield, in both the reactions of styrene with triethoxysilane (92%) and 1-octene with diphenylsilane (88%). Both Co(tpy)Br₂@SiO₂ and K₂CO₃ were easily separable from the hydrosilylated product, which contributed to achieving a reusable hydrosilylation system in both the catalyst and activator. Moreover, the Co(tpy)Br₂@SiO₂/K₂CO₃ system was found to be applicable in a continuous flow reactor as a catalyst in the stationary phase.