Dual-Ligand-Enabled Ir(III)-Catalyzed Enantioselective C-H Amidation for the Synthesis of Chiral Sulfoxides

A rational designed Ir(III)-catalyzed enantioselective C-H amidation of dibenzyl sulfoxides through desymmetrization and parallel kinetic resolution is demonstrated. An Ir(III) complex equipped with a t-butyl cyclopentadienyl ligand and paired with a modified chiral proline enables the highly enantioselective sulfoxide-steered C-H bond activation, providing an efficient and straightforward way to construct sulfur chiral centers. A wide range of dibenzyl sulfoxides and dioxazolones are compatible with this process, giving access to a variety of highly functionalized sulfoxide compounds with synthetically attractive amide substitution groups in good yields and enantioselectivities. Moreover, the flexible derivatization of the amidated sulfoxide was elaborated, providing various types of chiral sulfoxide scaffolds that would be potentially useful in asymmetric catalysis as chiral bidentate and tridentate ligands.