Correlation of the Rates of Solvolysis of Electron-Rich Benzoyl Chloride Using the Extended Grunwald-Wistein Equation

Abstract

The solvolysis rate constants of piperonyloyl chloride (1) in 27 different solvents are well correlated with the extended Grunwald-Winstein equation, using the N-T solvent nucleophilicity scale, Y-CI solvent ionizing scale, and I aromatic ring parameter with sensitivity values of 0.30 +/- 0.05, 0.71 +/- 0.02, and 0.60 +/- 0.04 for 1, m, and h, respectively. The solvent kinetic isotope effect values (SKIE, k(MeOH)/k(MeOD) and k(50%MeOD-50%D2O)) of 1.16 and 1.12 were also in accord with the values for the S(N)1 mechanism and/or the dissociative S(N)2 mechanism. The product selectivity values (5) for solvolysis of 1 in alcohol/water mixtures were in the range of 0.5 to 1.9, which is also consistent with the proposed unimolecular ionization mechanism.