Nickel-Catalyzed Enantioselective Pyridone C–H Functionalizations Enabled by a Bulky <i>N-</i>Heterocyclic Carbene Ligand

Annulated pyridones are an important scaffold found in many biologically active compounds. A Ni(0)-catalyzed C–H functionalization of 2- and 4-pyridones is disclosed, providing access to annulated pyridones via enantioselective intramolecular olefin hydroarylation. Key to the success of the transformation was the development of a sterically hindered and tunable N-heterocyclic carbene ligand resembling a chiral version of IPr. This ligand allows for mild reaction temperatures, and leads to the annulated pyridones in excellent yields and enantioselectivities.