Solvolysis mechanism of indan-2-yl arenesulfonates

Abstract

The solvolysis rates of 5-(Y)-substituted indan-2-yl (Z)-benzenesulfonates were determined in a variety of protic solvents at 45.0, 55.0 and 65.0 °C. Application of an extended Grunwald–Winstein equation indicates that kinetic responses to both solvent ionizing power, Y_OTs and solvent nucleophilicity, N_OTs, are relatively low but increase in parallel with increasing leaving ability, m= 0.39–0.46 and l= 0.32–0.41 for Z=p-Me ∼p-NO₂. The magnitude of cross-interaction constant. ρ_YZ, is also relatively small (0.16–0.32), which is, however, much more dependent on the nucleophilicity rather than the ionizing power of the solvent. These are consistent with the typical S_N2 mechanism proceeding through a transition state in which solvent participates in both bondmaking and -breaking processes.