A tandem allylsilane-vinylsilane difunctionalization by silylcupration of allene followed by reaction with alpha,beta-unsaturated nitriles.

Silylcupration of allene using phenyldimethylsilylcopper 1 followed by BF3-mediated reaction with alpha,beta-unsaturated nitriles at -40 degrees C affords allylsilane-vinylsilane-containing ketones resulting from consecutive addition (1,2 and 1,4) of the intermediate allyl- and vinylcopper species formed in the silylcupration of allene.