When we limit this analysis to single atom edits in the Mcule dataset, the pyrimidine-to-pyrrole and pyrimidine-to-imidazole transformations give similarly low percentages of commercial compounds (0.27% and 0.52%, respectively). The same thiazole-to-pyrrole transformation identified in our analysis of the Enamine database to be of high value also emerges (giving only 0.75% commercial products). However, several additional transformations, such as the pyrazineto-imidazole conversion (a carbon deletion giving 0.42% known products) and the isoxazole-topyrrole conversion (an oxygen transmutation giving 0.22% known products) emerge. The low percentages (0.22% to 2.94%) of commercial compounds that emerge from single-atom transformations of five-membered heteroaromatics further highlights the need for novel methodologies for single-atom point mutations of five-membered heteroaromatics.