Silylcupration of 1-Alkynylphosphine Oxides: Stereo- and Regioselective Synthesis of β-Silyl Substituted Vinylphosphine Oxides

β-Silyl substituted vinylphosphine oxides were prepared stereo- and regioselectively by the silylcupration of 1-alkynylphosphine oxides followed by hydrolysis or by reacting with other electrophiles.