The combination of the Suzuki–Miyaura cross-coupling and nucleophilic aromatic substitution of hydrogen reactions is a versatile tool for the syntheses of 4-(1R-pyrrol-2-yl)- and 4-(1R-indol-3-yl)-5-(hetero)aryl-substituted pyrimidines from commercially available 5-bromopyrimidine. The SNH [AE, (addition–elimination)] and SNH [AO, (addition–oxidation)] reactions of 5-bromopyrimidine with pyrroles and indoles were studied by gas chromatography–mass spectrometry. The structures of the intermediate σH adducts as well as the pyrrole-(hetero)arylpyrimidine and indole-(hetero)arylpyrimidine dyads were established for the first time by X-ray crystal structure analysis