Grunwald-Winstein equation derivation

The specific rates of solvolysis of benzyl p-toluenesulfonate and nine benzylic-ring-substituted derivatives (324) have been satisfactorily correlated using Aij and Tots scales within the extended Grunwald-Winstein equation. The reactions of Z-phenylethyl X-benzenesulfonates (325) with Y-pyridines (326) in acetonitrile at 60 °C have been studied at high pressures. The results indicated that the mechanism of the reaction moves from a dissociative 5)vr2 to an early-type concerted 5)vr2 with increasing pressure. 

For situations where solvent nucleophilicity may be a factor, Kevill (8) favors the use of the extended Grunwald-Winstein equation (equation 1). Scales of NOTs and OTs values based upon the use of methyl tosylate and 2-adamantyl tosylate as model SN2- and SNl-reacting substrates have been developed (15, 16). Also Y scales have been developed for other anionic leaving groups using 1-adamantyl or 2-adamantyl derivatives (17-19), where Sn2 reaction is impossible or severely hindered. 

Rates of solvolysis of cinnamoyl chloride and its 4-chloro and 4-nitro derivatives were analysed using the simple and extended Grunwald-Winstein equations. Studies of solvent effects in the solvolysis of isopropenyl, isobutyl,and propargyl chloroformate " and of 1- and 2-naphthyl chloroformate were reported. 

The specific rates of solvolysis of benzenesulfonyl chloride and a series of 4-and 2,4,6-substituted derivatives (Scheme 25) have been very well correlated using the extended Grunwald-Winstein equation, with incorporation of A/r solvent nucle-ophilicity and Tq solvent ionizing power values. In two instances, it was shown that almost identical correlations were obtained after the incorporation of methyl groups into the 2- and 6-positions of the benzene ring. No evidence was found for a dissociative (5n1) mechanism or for a duality of mechanism. All of the results could be rationalised in terms of a concerted bimolecular displacement (5n2) mechanism, involving attack by solvent at sulfur. ... 

In faet, the solvolysis of tert-butyl ehloride is one of the eomerstones of physieal or-ganie ehemistry. Thus, some quantitative approaehes to the kineties of spontaneous re-aetions in various solvents -and, more interesting, solvent mixtures- are based on linear free-energy relations sueh as that of Grunwald and Winstein or its extensions.These equations allow one to interpolate or extrapolate rate eonstants that eannot be readily measured, and also to derive meehanistieally signifieant information in the proeess. 

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