Double Silylation of Olefin with HSiCl3 in the Presence of Bu4PCl. New Synthetic Method for α,β-Bis(trichlorosilyl)alkanes

Terminal and activated internal olefins such as 1-hexene, 1-decene, styrene, p-methylstyrene, 1-phenylprop-l-ene, and stilbene reacted with a mixture of HSiCl3 and SiCl4 in the presence of Bu4PCl at 180 °C for 4−16 h to give the α,β-bis(trichlorosilyl)alkanes 2 (70−85%) and alkyltrichlorosilanes 3 (10−21%). However, the reactions of the unactivated internal olefins 3-hexene and cyclopentene for 32 h under the same conditions gave 41% and 85% consumption and produced the bis-silylation compounds 2 in 12 and 43% yields along with hydrosilylation products 3 in 24 and 28% yields, respectively.