Asymmetric silanes: A synthesis of nonracemic alkenylhydrosilanes has been developed based on the desymmetrization of a dihydrosilane through alkenylation with an alkyne using an asymmetric catalyst. The alkenylhydrosilane product can be used as a versatile chiral building block for other functionalized nonracemic silanes through the stereoselective conversion of its hydride and/or alkenyl moiety.