Rhodium-Catalyzed Enantioselective Silylation of Arene C–H Bonds: Desymmetrization of Diarylmethanols

We report a Rh-catalyzed, enantio­selective silylation of arene C–H bonds directed by a (hydrido)­silyl group. (Hydrido)­silyl ethers that are formed in situ by hydrosilylation of benzophenone or its derivatives undergo asymmetric C–H silylation in high yield with excellent enantio­selectivity in the presence of [Rh­(cod)­Cl]₂ and a chiral bisphosphine ligand. The stereo­selectivity of this process also allows enantio­enriched diarylmethanols to react with site selectivity at one aryl group over the other. Enantioenriched benzoxasiloles from the silylation process undergo a range of transformations to form C–C, C–O, C–I, or C–Br bonds.