A benchmark system using chlorovinyl quinoline 1 and aniline was used for reaction development (Table ). An initial screening campaign identified promising conditions using 20 mol% catalyst 3 at -20 ºC in CPME (Entry 1; for full screening details, see Tables ). However, further attempts at reaction optimization did not improve asymmetric induction. We therefore conducted an extensive catalyst screen (see Table ), which, in combination with DFT analysis (vide infra), allowed catalyst SAR to be rationalized and provided insight into substituent effects more broadly. The parent, unsubstituted BINOL catalyst 4 delivers low enantioselectivity (entry 2), as expected from prior work in this field. Systematic exploration of the aryl groups at the 3,3'-substituents to understand the selectivity determinants of catalyst 3 was informative. As expected, 19 3,3'- diphenyl catalyst 5 delivered improvement upon the enantioselectivity offered by unsubstituted catalyst 4 (entry 3). However, introduction of an i-Pr group at the 4-position of the 3,3'-aryl units (6) had no effect on enantioselectivity (entry 4), suggesting this position has very little effect on enantiofacial discrimination. Selectivity increased marginally by moving the i-Pr groups to the 3,5-positions (7, entry 5); however, selectivity remained significantly lower than for 3 even when the steric component was increased, for example, with t-Bu-substituted catalyst 8 (entry 6). These data suggested the 3-,4-, and 5-positions of the 3,3' aryl units exert a weak influence on stereoselectivity. This was compounded by assessment of catalyst 9, which lacks the 4-(i-Pr) unit yet delivers approximately the same enantioinduction as 3 (entry 7 vs. entry 1). The lower importance of the 3-, 4-, and 5-positions of the aryl unit was further supported by assessment of a range of functional groups at these positions on the BINOL scaffold as well as in alternative catalyst frameworks (Table ). However, while having little to no effect on enantioinduction, the 4-position of these aryl units was found to directly affect reactivity: increased conversion (ca. 20%) to product was observed for those catalysts with 4-i-Pr compared to those without (5 vs. 6, 9 vs. 3).