The stereoselectivity of the reaction arises from interactions between the substrate, the sulfonamide, and the phenyl substituent on the indenyl ligand of the catalyst. Our computational studies demonstrate that during C-N bond formation from A5 to A7, the tosyl group and the alkyl chain on the olefin are both positioned within the same quadrant. In the context of (S)-product formation, the tosyl and alkyl groups adopt an orientation opposite to that of the phenyl substituent, spanning from S A5 to S A7. Conversely, for the formation of the (R)-product, two Clearly, this distinction leads to a variation in steric interaction. Both distortion-interaction analysis and the energy decomposition analysis indicate that the primary contribution to the energy difference between S A5-TS and R A5-TS arises from steric interactions, accounting for the difference of 1.9 kcal/mol (Figure ). Further details can be found in the Supporting Information.