Access to Atropisomeric Biaryls by Harnessing C−H Activation and Ring Opening of Cyclic Diaryliodonium Salts

Abstract

Asymmetric ring-opening of cyclic diaryliodonium salts has emerged as an efficient strategy for accessing axially chiral biaryls. However, existing methods are largely restricted to copper-catalyzed reactions using heteroatom nucleophiles, and general enantioselective C−C bond-forming approaches remain elusive. Herein, we disclose a Rh(III)-catalyzed enantioselective arylation and acylation of cyclic diaryliodonium salts by the merger of C−H activation and atroposelective ring opening of cyclic diaryliodonium salts. This transformation enables asymmetric conversion of cyclic diaryliodonium salts with electron-poor arenes and aldehydes as coupling partners. The protocol affords two structurally distinct classes of axially chiral biaryls with broad substrate scope (92 examples), generally good yields, and enantioselectivities (up to >99% ee). Derivatization applications highlight the synthetic applicability and potential of the axially chiral scaffolds. This work provides a platform for the modular synthesis of multifunctional, highly enantioenriched axially chiral biaryl frameworks and expands the reaction paradigm of asymmetric transformations of cyclic diaryliodonium salts.