Cross interaction constants as a measure of the transition state structure (part III). Mechanism of reactions between 1‐phenylethyl benzenesulfonates with N,N‐dimethylanilines

Abstract

Abstract The kinetics and mechanisms of the reactions between 1‐phenylethyl benzenesulfonates (1‐PEB) with N,N‐dimethylanilines are investigated in methanol at 35·0°C. Reactivity and selectivity trends were found to be similar to those for the reactions of 1‐PEB with anilines, but the magnitudes of cross interaction constants, ρXZ, between substituents X in the nucleophile and Z in the leaving group were substantially smaller indicating no hydrogen‐bond bypass bridge formation in the transition state. However, the magnitude of ρXZ suggested a direct electrostatic interaction between the reaction centers in the nucleophile and leaving group in the frontside nucleophilic attack with a loose transition state structure.