Homogeneous Catalytic Hydrosilylation of Pyridines.

The color change from yellow to violet allows the formation of the intermediate [Cp2 Ti(SiHMePh)(pyridine)] to be monitored in the reaction of PhMeSiH2 with a pyridine in the presence of the precatalyst [Cp2 TiMe2 ] [Eq. (a)]; the hydride [Cp2 TiH] is postulated to be the key intermediate in the catalytic cycle. The regioselective hydrosilylation of pyridine and also substituted pyridines can be catalyzed by the titanocene [Cp2 TiMe2 ]. R=Me, CO2 Et.