For example, assuming 1000 pyridines exist in the starting dataset, and 1000 pyrroles are generated from the 1000 pyridines, if there are only 500 pyrroles in the starting dataset, a maximum of 500 of the 1000 generated pyrroles would be designated as characterized compounds. To overcome this limitation that arises from limited representation of certain heteroaromatics in the starting dataset, the number of characterized products to the total number of characterized molecules containing the same heterocycle type is normalized in our workflow. Additionally, the opposite case is possible, where fewer molecules of a certain heterocycle type are generated than exist in the starting dataset. For example, assume 500 pyrimidines exist in the starting dataset and 500 imidazoles are generated from those 500 pyrimidines. If 1000 compounds characterized as imidazoles exist in the starting dataset, the number of starting pyrimidines becomes limiting. If 100 of the 500 generated imidazoles are characterized in the starting dataset, we normalize the 100 characterized imidazole products to the 500 starting pyrimidines. Both normalization tactics lead to a limit of 1.00 for each transformation (see Figure for normalization of the enamine database). Importantly, because of these normalization steps, the products a transformation generates that are previously characterized (expressed as a percentage) is not the difference between the percentage of those products that are uncharacterized and 100%.