Silyl-Group-Directed Linear-Selective Allylation of Carbonyl Compounds with Trisubstituted Allylboronates Using a Copper(I) Catalyst

A copper(I)-catalyzed linear-selective allylation of carbonyl compounds with trisubstituted allylboronates has been achieved by capitalizing on the electronic and steric effects of silyl groups. This reaction provides stereodefined trisubstituted homoallyl alcohol derivatives that bear a synthetically useful alkenyl silane moiety. The results of a computational study suggested that the silyl directing group thermodynamically stabilizes the sterically hindered allylcopper(I) intermediate and kinetically facilitates the carbonyl allylation path for the linear product by lowering the energy of its transition state.