The lower and upper bounds for the six continuous reaction variables are shown in Table . 1morpholine-1-cyclohexene I (40 mM) was used as the liming reactant alongside 1.0 -2.0 equivalents of 1,1-diphenylethylene II and HE, based on the proposed reaction mechanism (Scheme 1). If HE solubility in a particular solvent was less than 80 mmol/L (i.e., 2.0 equivalence for HE), then that solubility value was used as the upper limit for HE, to maintain a clear solution for higher light penetration. For instance, a 1.51 equivalence was used as the upper limit for HE in 2-propanol (IPA), given the solubility for HE in IPA was measured to be 60.47 mmol/L (Table , ESI). A clear reaction solution is important for achieving high and uniform light penetration to promote faster reactions and to avoid light scattering, which introduces an unknown parameter in the model, given the variations in the particle size and quantity in different solvents, and for the algorithm to learn the relevant descriptors (i.e., intrinsic solvent properties). Lower and upper bounds of 0.5 -5.0 mol% were selected for the Ir(ppy)3 catalyst based on the UV-vis absorption spectra measurements (Figure , ESI), solubility in various solvents, and the range reported in literature. Due to its catalytic role for reaction initiation and iminium ion (Int-I) formation, propionic acid range was set as 0.1 -