Nickel-Catalyzed Enantioselective Pyridone C-H Functionalizations Enabled by a Bulky N-Heterocyclic Carbene Ligand

Annulated pyridones are an importantscaffold found in many biologically active compounds. ANi(0)-catalyzed C−H functionalization of 2- and 4-pyridones is disclosed, providing access to annulatedpyridones via enantioselective intramolecular olefin hydro-arylation. Key to the success of the transformation was thedevelopment of a sterically hindered and tunableN-heterocyclic carbene ligand resembling a chiral version ofIPr. This ligand allows for mild reaction temperatures, andleads to the annulated pyridones in excellent yields andenantioselectivities.