The α,β-unsaturated sulfones are suitable activated olefins in catalytic asymmetric conjugate β-boration. These substrates undergo smooth conjugate addition of bis(pinacolato)diboron [B2(pin)2] catalyzed by nonracemic CuI-diphosphine complexes to provide, upon subsequent oxidation, β-hydroxy sulfones in good yields and high enantiocontrol.
