Enantioconvergent Synthesis of Allyl Boronates

Significance

The authors report a remarkable copper-catalyzed enantioconvergent borylation reaction of cyclic allylic ethers, in which each enantiomer of the racemic mixture is converted into the same enantiomer of the product through different reaction pathways. This is a rare phenomenon and in contrast to dynamic kinetic resolutions (DKR) and dynamic kinetic asymmetric transformations (DYKAT), there is no equilibration of enantiomers or loss of chirality. The allyl boronates are extremely versatile reagents for organic synthesis, and the authors demonstrate the utility of these reagents for the stereoselective construction of quaternary centers.