Copper(II)-Catalyzed Silyl Conjugate Addition to α,β-Unsaturated Conjugated Compounds: Brønsted Base-Assisted Activation of Si–B Bond in Water

A mild method for the installation of the dimethylphenylsilyl group on the β-carbon of electron-deficient olefins is reported. In the presence of a catalytic amount of copper(II) (1 mol %) and amine base (5 mol %) at rt, the transformation proceeds efficiently in water within 1.5-5 h to afford β-silylated products in yields of up to 90%.