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 α-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
byproduct is nitrogen. Furthermore, other similar heterocyclic scaffolds
can also be functionalized regioselectively under the developed conditions.