Copper-Catalyzed Borylative Aromatization of p-Quinone Methides: Enantioselective Synthesis of Dibenzylic Boronates.

In this report, we establish that DM-Segphos copper(I) complexes are efficient catalysts for the enantioselective borylation of para-quinone methides. This method provides straightforward access to chiral monobenzylic and dibenzylic boronic esters, with enantiomeric ratios up to 96:4, using a commercially available chiral phosphine. Standard manipulations of the C-B bond afford a variety of chiral diaryl derivatives.