Iridium-Catalyzed Site- and Enantioselective C(sp²)-H Borylation of Benzhydryl Ethers: Enantioselectivity Amplification by Kinetic Resolution Relay

We herein report a simple ether-directed iridium-catalyzed site- and enantioselective C(sp²)-H borylation of benzhydryl ethers for the first time. Various chiral benzhydryl ethers were obtained with high enantioselectivities in the presence of a tailor-made chiral bidentate boryl ligand. We found that the kinetic resolution relay significantly amplified the enantioselectivity. The synthetic utility of the current method was demonstrated by gram-scale C—H borylation and C—B bond transformations. (Figure presented.).