These libraries could be used to develop "ideal" acid or amine substrates for evaluation, but for every unique application, it may be advantageous to further curate the space, either by identifying a subset of compounds relevant to the reaction of interest (e.g., aryl/heteroaryl carboxylic acids) or by selecting a specific subset of descriptors based on a mechanistic hypothesis. Descriptors from these libraries can be downloaded to facilitate chemical space curation or to probe structureactivity relationships by building predictive models with these commonly employed substrate classes. Furthermore, once a predictive model has been identified and validated, expansive libraries of this type are poised to expedite virtual screening.