The cycloaddition reaction of the morpholino enamines of N-methylpiperidone and N-methyl tropinone with sulfonylazides was exploited, leading to a click-chemistry approach to uncommon azacycloalkene monosulfonyl diamines in good yields. A computational model for the key step decomposition of the triazoline intermediate was then realized by DFT calculations. The model explains the observed reaction outcome and leads to a new interpretation of the decomposition mechanism for 5-amino-1,2,3-triazolines.