In step 4, analogue reactions that only contain the aforementioned analogue or query species are extracted from the Reaxys® data. More specifically, all reactants and reagents in these reactions are required to be analogue or query species, ensuring that reactions between designated carrier fragments are possible. For instance, Error! Reference source not found.a involves hydroquinone (analogue species, containing the aromatic amine carrier fragment) and acetic anhydride (query species) as reactants, and acetic acid (query species) as a reagent. The reader is referred to the Section S1 in the ESI for more details on definitions of species roles in this work. The final result is a list of 243,600 analogue reactions, ready to be processed in the next portion of the workflow.