Abstract
A reaction between azide, alkyne and 2H-azirine resulted in C-C bond formation at position five of 1,2,3-triazole, instead of previously misidentified C-N bond connectivity. The reaction mechanism of this C-C bond formation on the triazole ring was fully explained by employing calibrated QM(DFT-D3) calculations. Functionalization of primary products provided substituted pyrimidine, furan or 1,3-oxazepine.