Rhodium(III)-Catalyzed C6-Selective Arylation of 2‑Pyridones and Related Heterocycles Using Quinone Diazides: Syntheses of Heteroarylated Phenols

An
efficient, direct C6-arylation of 2-pyridones has been successfully
accomplished with quinone diazides under Rh­(III)-catalyzed redox-neutral
conditions. The optimized method is simple, mild, and highly regioselective
with a broad substrate scope. The strict regioselectivity is guided
by the pyridyl substituent attached to the nitrogen of the pyridone
ring. As the directing 2-pyridyl group can easily be removed at any
suitable stage after functionalization, the method provides a facile
access to complex heteroarylated phenol moieties by wide-ranging heterocyclic
scaffolds.