Tridentate Sulfoxide- N -olefin Hybrid Ligands in Rhodium-Catalyzed Asymmetric Allylic Substitution.

A well-defined tridentate chiral sulfoxide- N -olefin ligand has been designed and applied in rhodium-catalyzed asymmetric allylic substitutions of racemic allylic carbonates, providing the branched allylic products in good yields with good to high enantioselectivities and excellent regioselectivities. This reaction mechanism, which involves the possible hemilability of olefin coordination on sulfoxide- N -olefin hybrid ligands with rhodium, is elaborated as well.