Efficient aerobic oxidative dehydrogenation of dihydropyrimidinones and dihydropyrimidines

4-Substituted dihydropyrimidinones and dihydropyrimidines were first efficient aerobic oxidized to the corresponding pyrimidinones and pyrimidines, respectively, in high yields by molecular oxygen in the presence of catalytic amount of N-hydroxyphthalimide (NHPI) and Co(OAc)2 in a mild and environmental benign condition.