Chiral Transient Directing Groups for Catalytic Asymmetric Intramolecular Alkene Hydroacylation

We developed a chiral 2-aminopyridine as a cocatalyst with Rh(I) to accomplish highly enantioselective intramolecular alkene hydroacylation reactions (up to 96:4 er). The chiral 2-aminopyridine served dual purposes: a transient directing group for aldehyde C–H activation and the sole source of asymmetry in the transformation. Our chiral transient directing group approach overcame prior limitations in asymmetric hydroacylation reactions, where reactants containing embedded chelating groups were required for success. We demonstrated our method in enantioselective syntheses of two biologically relevant small molecules.