Atroposelective Desymmetrizing Iodination via Chiral Phosphoric Acid Catalysis: Synthesis of Axially Chiral Biaryl Phosphine Oxides

Abstract Herein, we report a CPA-catalyzed atroposelective iodination of prochiral phosphine oxides bearing no hydrogen-bond-donor substituents, affording a range of 3′-iodinated axially chiral biaryl phosphine oxides in excellent yields and enantioselectivities. The reaction proceeds through synergistic noncovalent interactions among the iodinating reagent, the catalyst, and the substrate, eliminating the need for substrate pre-functionalization or external additives. The method accommodates both di-tert-butyl and dicyclohexyl phosphine oxide substrates, as well as diverse substitution patterns on both aromatic rings.