C6-Selective Direct Alkylation of Pyridones with Diazo Compounds under Rh(III)-Catalyzed Mild Conditions

A Rh(III)-catalyzed highly efficient C6-alkylation of 2-pyridones has been achieved successfully with a-diazo carbonyl compounds. The developed method is simple, mild, and highly regioselective with a broad range of substrate scope. The regioselectivity is guided by the pyridyl substituent attached to the nitrogen center of the pyridone ring. The directing group can be easily removed, and the only formed by product is nitrogen. Furthermore, other similar heterocyclic scaffolds can also be functionalized regioselectively under the developed conditions.