Copper(I)-Catalyzed Dehydrogenative Amidation of Arenes Using Air as the Oxidant

The copper(I) bromide-catalyzed intermolecular dehydrogenative amidation of arenes via C-H bond activation assisted by a 2-pyridyl or 1-pyrazolyl chelating group using air as the terminal oxidant has been achieved at 140 degrees C. N-Aryl amides, N-alkyl amides, benzamide derivatives, imides, and lactams all are good coupling partners to obtain moderate to excellent yields. The amount of solvent is critical for the transformation: both increasing and decreasing the amount of solvent decreased the yield. Notably, the amidation of bimolecular 2-phenylpyridine with the dual N-H bonds of a primary amide proceeded smoothly in one-pot to afford a good yield under the same conditions. The amidation can be performed with a good yield at the gram scale.