The AL strategy employed in this work to train MLPs is illustrated in Fig. . The first step involves generating a small set of configurations labelled with reference energies and forces. This information is used to train the initial version of the MLP. For a given reaction, we employ two different training sets, one containing the reacting substrates in the gas phase (or implicit solvent) and another including explicit solvent molecules. The latter is necessary to account for specific non-covalent interactions between the solute and solvent.