Due to the proposed proximal influence of the steric environment around the phosphoric acid moiety on selectivity, the probe was docked taking the place of the P atom in the BINOL and SPINOL backbones (Figure ). The original CycH_12 molecular probe was implemented in the SMART workflow for these structures. Upon visual inspection of the docked scaffolds the probe was determined to be too long and would likely parametrize redundant space far from the binding site (Figure ). While this could be resolved during the descriptor computation step by only considering proxVCAVITY, we employed a shorter probe (CycH_10) to increase the speed of conformer generation. SMART Descriptor Analysis for Phosphoric Acid Catalysts. SPINOL catalysts were initially designed to provide more constrained and rigid reactive cavities than their BINOL analogs. Analysis of the VCAVITY for various substituted SPINOL and BINOL catalysts shows a linear correlation between backbones (Figure ) supporting linear scaling of substituent bulk between backbone scaffolds. SPINOL catalysts generally have a smaller VCAVITY than BINOL analogs (Figure ), supporting the initial design impetus for SPINOL scaffolds. A more complex trend between BINOL and SPINOL became apparent through analysis of VOCTANT.