Cu-catalyzed asymmetric conjugate additions of dialkyl- and diarylzinc reagents to acyclic β-silyl-α,β-unsaturated ketones.: Synthesis of allylsilanes in high diastereo- and enantiomeric purity

[GRAPHICS] A readily available and simple (MW = 444.5 g/mol) valine-based chiral phosphine is used to promote highly efficient catalytic asymmetric conjugate additions of dialkyl- and diarylzinc reagents to acyclic beta-silyl-alpha,beta-unsaturated ketones. The catalytic asymmetric protocol allows access to versatile allylsilanes that bear a trisubstituted olefin in high diastereo- and enantiomeric purity.