Calcium-Catalyzed Direct Coupling of Alcohols with Organosilanes

A calcium-catalyzed direct substitution of pi-activated alcohols with different organosilanes under very mild reaction conditions is presented. The high reactivity of the calcium catalyst allows efficient conversion of secondary and tertiary allylic, secondary benzylic, and tertiary propargylic alcohols with allyltrimethylsilane at room temperature. Furthermore, the first direct substitution of an alcohol with (E)- as well as (Z)-alkenylsilanes was achieved under mild reaction conditions.