Given the variety of data sources, patents (USPTO and Pistachio), literature and patents (Reaxys), and industrial data (AstraZeneca ELN), it is interesting to note that a comparable number of templates were extracted from the Reaxys and Patent datasets (Table ). However, whilst both template sets are similar in size they differ in their coverage of the reaction space as highlighted in Figure . The inclusion of the Reaxys data offers a greater breadth of unique reaction templates, accounting for 41.1 % of the overall combined dataset. The comparably high number of unique templates extracted from the combined patents data (32.5 %), suggests that a considerable portion of patents data covered are not present in Reaxys (7.4 % overlap), or that the structural components that make up the templates are unique to Reaxys. The exact differences between the patent coverage of the patent datasets (USPTO and Pistachio) and Reaxys is not clear with regards to the templates that can be obtained. Furthermore, the increased number of structural components and templates unique to the Reaxys dataset may be a residual artefact of multi-step reaction pathways. In this regard, we have filtered for all multi-step reactions, such that they have been removed from the dataset to the best of our knowledge.