Synthesis of Adjacent Quaternary Stereocenters by Catalytic Asymmetric Allylboration

Allylboration of ketones with γ-disubstituted
allyl­boronic
acids is performed in the presence of chiral BINOL derivatives. The
reaction is suitable for single-step creation of adjacent quaternary
stereo­centers with high selectivity. We show that, with an appropriate
choice of the chiral catalyst and the stereo­isomeric prenyl
substrate, full control of the stereo- and enantio­selectivity
is possible in the reaction.