Enantioselective Synthesis of α-Tri- and α-Tetrasubstituted Allylsilanes by Copper-Catalyzed Asymmetric Allylic Substitution of Allyl Phosphates with Silylboronates

A copper/N-heterocyclic carbene-catalyzed asymmetric allylic substitution of allyl phosphates with a silylboronate has been developed to give highly enantioenriched allylsilanes. High regioselectivity has been achieved by employing NaOH as the base, and this catalyst system is effective for both γ-mono- and disubstituted allyl phosphates.