Rhodium-Catalyzed C6-Selective C-H Borylation of 2-Pyridones.

A pyridine-directed, rhodium-catalyzed C6-selective C-H borylation of 2-pyridones with bis(pinacolato)diboron (pinB-Bpin) has been developed. The reaction proceeds smoothly under relatively mild conditions, and the corresponding C6-borylated 2-pyridones are obtained with perfect site selectivity. Subsequent palladium-catalyzed Suzuki-Miyaura cross-coupling is followed by the removal of the pyridine directing group to form the C6-arylated NH-pyridone in an acceptable overall yield.