Catalytic Enantioselective Silylation for Simultaneous Axial and Central Chirality in Diaryl Ethers

Axially chiral diaryl ethers represent a distinctive class of atropisomers wherein rotation about the C-O bond is restricted. Efficient methods for accessing such architectures remain limited. Herein, we report a copper-catalyzed enantioselective silylation of 2-aryloxyisophthalaldehydes using an N-heterocyclic carbene chiral ligand and an Si-B pronucleophile. This approach concurrently establishes both central and axial chirality with high enantioselectivity and diastereoselectivity (up to 95:5 er, >20:1 dr). The resulting axially and centrally chiral products display excellent thermal stability and can be further elaborated into valuable diaryl ether derivatives with minimal erosion of enantiopurity.