Aryl Chloride-Directed Enantioselective C(sp<sup>2</sup>)-H Borylation Enabled by Iridium Catalysis
Hongliang Zhao, Chaoyue Zhao, Lili Chen, Chungu Xia, Xin Hong, Senmiao Xu
Abstract
We herein report the iridium-catalyzed enantioselective C–H borylation of aryl chlorides. A variety of prochiral biaryl compounds could be well-tolerated, affording a vast array of axially chiral biaryls with high enantioselectivities. The current method exhibits a high turnover number (TON) of 7000, which represents the highest in functional-group-directed asymmetric C–H activation. The high TON was attributed to a weak catalyst-substrate interaction that was caused by mismatched chirality between catalyst and substrate. We also demonstrated the synthetic application of the current method by C–B, ortho- C–H, and C–Cl bond functionalization, including programmed Suzuki–Miyaura coupling for the synthesis of axially chiral polyarenes.