Solvolysis of Allyl Arenesulfonates. Cautionary Comments concerning the NOTs Scale of Solvent Nucleophilicities

Article abstract of DOI:10.1021/jo00217a009

The rates of solvolysis of five allyl arenesulfonates are analysed in terms of the extended Grunwald-Winstein equation.The l values are constant but the m values decrease slightly as the nucleofugality of the leaving group increases.The solvent nucleophilicity (N_OTs) values presently available in the literature are based upon a m value for methyl p-toluenesulfonate (tosylate) solvolysis of 0.3; it is demonstrated that a value of 0.55 is more appropriate.The previously reported l values and correlation coefficients for tosylate ester solvolyses are accurate and the "ap parent" sensitivities to solvent ionizing power (m values) are easily corrected.However, for use in conjunction with solvent ionizing power scales for other leaving groups, N_Ts values based on the appropriate m value or, alternatively, N_Et3O+%& values (based on triethyloxonium ion solvolysis) are required.