Stahl and co-workers have developed a highly reactive aerobic oxidation . This promising methodology enables completion of the reaction in 30 min at room temperature (entry 1). However, four kinds of catalysts were used, and a simpler catalytic system would be preferable. The highly reactive catalyst, 9azanoradamantane N-oxyl (nor-AZADO), was tried with NaNO2 as a cocatalyst, which resulted in completion of the reaction in 60 min (entry 2) . While this led to a simpler catalyst system, nor-AZADO is expensive. Hong and co-workers have developed a low-cost catalyst system using TEMPO and nitrate salts . Fe(NO3)3 (entry 3), Cu(NO3)2 (entry 4), Zn(NO3)2 (entry 5) worked as catalysts combined with TEMPO.