The rapid incorporation of alkyl and acyl groups into C−H bonds of N-heterocycles is in demand for the development of lead candidates in drug discovery. Notably, a combination of KBrO₃ and Co(II) catalyst was successfully employed for the generation of alkyl and acyl radicals from DHPs. A series of heterocycles including azauracils, quinoxalinones, pyrazinones, pyridones, quinolones, quinazolinones, xanthines, chromones, and azine N-oxides were compatible under the developed conditions. Additionally, new azauracil derivatives were created using various 1,4-dihydropyridines. Combined mechanistic investigations aided the elucidation of a plausible reaction mechanism.