Solvolysis of Sulphonyl Halides. I. The Hydrolysis of Aromatic Sulphonyl Chlorides in Aqueous Dioxan and Aqueous Acetone

Jenkins, FE; Hambly, AN

doi:10.1071/ch9610190

Cited by 17 publications

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“…On the other hand, hindered structures based on derivatives of benzene sulfonyl chloride have shown a significant increase in reactivity, the so‐called positive steric effect, which is in disagreement with the classical interpretation of the electronic effect of substituents on the rate of S N 2 processes . Based on the described observations, and others already available in the literature, deviations of the TS structure are expected for a number of hindered substrates …”

Section: Introductioncontrasting

confidence: 49%

Solvent network at the transition state in the solvolysis of hindered sulfonyl compounds

Iazykov

Rublova

Canle

et al. 2016

J of Physical Organic Chem

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Alcoholysis rates of unhindered benzenesulfonyl chlorides (X‐ArSO2Cl, X = H‐; 4‐Br‐; 4‐Me‐) are similar in methanol; the same behavior is also observed in ethanol, whereas the reactivity order in iso‐propanol is 4 Me‐ < H‐ < 4‐Br‐. On the other hand, alcoholysis of sterically hindered arenesulfonyl chlorides (X‐ArSO2Cl) (X = 2,4,6‐Me3‐3‐NO2‐; 2,6‐Me2‐4‐tBu‐; 2,4,6‐Me3‐; 2,3,5,6‐Me4‐; 2,4,6‐iPr3‐; 2,4‐Me2‐; 2,4,6‐(OMe)3‐) in all studied alcohols show a significant increase in reactivity, the so‐called positive steric effect. Most of the substrates showed a reaction order b ~ 2 with respect to the nucleophile in methanol and ethanol, and b ~ 3 in iso‐propanol. The correlation between reactivity and the Kirkwood function (1/ξ) gives negative sensitivity (U) for all systems. All substrates showed high sensitivity to media nucleophilicity that depends on ΣσX. Obtained results suggest the alcoholysis of benzenesulfonyl chlorides proceeds through SN2 mechanism where the transition state (TS) involves the participation of 2–3 alcohol molecules; such a TS can be cyclic, in the case of unbranched alcohols, or linear, for alcohols with bulkier hydrocarbon groups like iso‐propanol. To include the number of alcohol molecules playing such a role in the TS, the following terminology is proposed: cSN2sn for SN2 reactions involving n solvent molecules in a cyclic (c) TS, where “s” stands for the solvent and “n” is either the closest integer or half‐integer to the reaction order relative to the solvent or, in computational studies, the proposed number of solvent molecules taking part in the TS, whereas SN2sn is proposed when the TS is not cyclic. Copyright © 2016 John Wiley & Sons, Ltd.

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Section: Introductioncontrasting

confidence: 49%

Solvent network at the transition state in the solvolysis of hindered sulfonyl compounds

Iazykov

Rublova

Canle

et al. 2016

J of Physical Organic Chem

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“…Thus Swain and Scott (12) report what might be called a "selectivity ratio" of lc,, -/kHz, = 7 x lo5 for benzenesulfonyl chloride compared to the range about lo3 for the primary halides (4,9,19). The effect of para-substitution on the rate of hydrolysis of this series in water is consistent with the requirements of an S,2 mechanism (though Hedlund appears to reach a different conclusion (2)).…”

Section: Discussionmentioning

confidence: 99%

Heat capacity of activation for the hydrolysis of methanesulfonyl chloride and benzenesulfonyl chloride in light and heavy water

Robertson¹,

Rossall²,

Sugamori³

et al. 1969

Can. J. Chem.

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Rates of solvolysis of methanesulfonyl chloride and benzenesulfonyl chloride have been determined in H 2 0 and D,O. The free energy, enthalpy, entropy, and heat capacity of activation were calculated. The exceptional accuracy of the data permitted an estimation of dAC,*/dTfrom a four parameter temperature dependence of the kinetic rates.From these data we conclude that both sulfonyl chlorides hydrolyse by the same mechanism (SN2) The change in R from CH3 to CsH5 in RS02CI did not alter AC,* but AS* (20') was changed from -8.32 to -13.25 cal deg-' n~o l e -~, resoectivelv. The significance of this difference is attributed to the probability of bond formation rather than to differences-in solvent reorganization.Canadian Journal of Chemistry, 47. 4199 (1969) This paper is the first of a series reporting detailed studies of the hydrolysis of sulfonyl chlorides5. The experimental approach is the same'as that applied in preceding studies on the halides and sulfonates: a careful examination of the effect of temperature and of isotopic substitution in the solvent on the temperature dependence of the rate of hydrolysis.In the halide series we found a remarkable similarity in the values of the heat capacity of activation, AC,,' (lo), and in the differences in AG* for hydrolysis in H,O and D,O over a range of structures for which it was reasonable to expect different degrees of bond-making in the activation process (11). These observations led to the conclusion that the SN2 transition state was reached when the charge on the halide being displaced created interaction with the solvent equal to water-water interaction; i.e. the transition state corresponded to that degree of charge development where exothermic solvation of the quasi-halide was about to begin. Consequently, it followed that for a given temperature, the charge level (ti-) on the chlorine atom, for example, is the same whether the ion is being displaced from allyl, ethyl, or methyl chloride. This in turn implies that the charge level on the anion at the transition state of an SN2 displacement is independent of the degree of nucleophilic interaction. The evidence in favor of this con-'NRCC No. 10 915. ZPresent address: Chemistry Department, The University of Calgary, Calgary, Alberta. 3NRCC Postdoctoral Fellow, 1968-1969. 4NRCC Postdoctoral Fellow, 1965. 5For references to previous work, see refs. 1-9. clusion derived from the similarity in AC,* values and from the limited range of 6 4 H * = AHD2o* -AHHzo* for SN2 displacement for the hydrolysis of alkyl halides, is weakened by the possibility that the difference in the degree of bond-malung at the transition state for the hydrolysis of the available halides is small, a possibility suggested by the uniformity of our kinetic solvent isotope effect (k.s.i.e.) values (10).To fill this deficiency we were led to examine the hydrolysis of the sulfonyl chlorides, since in this series there are good indications that a greater degree of nucleophilic overlap is required at the transition state (10, 12). We assumed ...

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“…Any attempt t o account for rate ratios from a simple consideration of the electronic distribution in the substituted sulphonyl chloride molecule, without regard to the nature of the solvent (Geiseler and Asinger 1956 ; Hall 1956) must fail. I n terms of the theory of Grunwald and Winstein (1948) and Winstein, Grunwald, and Jones (1951) which was used in the discussion of relative rates of hydrolysis of aromatic sulphonyl chlorides (Jenkins and Hambly 1961), it is necessary to assume that there is a continuous change in the nature of the transition state as the composition of the solvent is varied. I n the media of low water content the formation of the activated complex involves the close approach of the nucleophilic water molecule to the electrophilic sulphur atom, a process that will be favoured by the presence of electron-attracting substituents in the group R (structure (I)).…”

Section: Discussionmentioning

confidence: 99%

“…The effect of substituents on the rates of hydrolysis of aromatic sulphonyl chlorides in aqueous dioxan or aqueous acetone undergoes a reversal as the composition of the solvent is changed (Hedlund 1940 ;Jenkins and Hambly 1961). Electron-attracting groups in the puru-position increase the rate of hydrolysis while electron-donating groups retard it for most of the range of solvent compositions.…”

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confidence: 99%

Solvolysis of Sulphonyl Halides. IV. The Hydrolysis of Some Substituted Aliphatic Sulphonyl Chlorides and of Ethanesulphonyl Bromide in Aqueous Dioxan

Foon¹,

Hambly²

1962

Aust. J. Chem.

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The effects of substitution in the alkyl group of an alkanesulphonyl chloride, on the rate of hydrolysis, vary with the solvent composition. The relative rates can be explained in terms of the theory of Grunwald and Winstein that there is a continuous range of transition complexes, with " bond making " between the water molecule and the sulphur atom controlling the rate in the less aqueous media, u~hile the stretching and charging of the sulphur to chlorine bond controls the rate in solvents of higher water content. The inhibition of the simple Sh-2 reaction, which gives rise to a maximum rate constant as the composition of the solvent approaches pure water, resembles that noted with methane-and ethanesulphonyl chlorides.The hydrolysis of ethanesulphonyl bromide, a t 25 "C, proceeds a t three to eight times the rate for the corresponding sulphonyl chloride in solvents varying in composition from 0.99 to 0.2 mole fraction of water with dioxan. Over most of the solvent range both the entropy and enthalpy of activation are favourable to a higher rate of solvolysis for the sulphonyl bromide.* The experimental work was performed in the Chemistry Department, LTniversity of fiIelbourne. For Part I11 of this series see Foon and Hambly (1962).

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Solvolysis of Sulphonyl Halides. I. The Hydrolysis of Aromatic Sulphonyl Chlorides in Aqueous Dioxan and Aqueous Acetone

Cited by 17 publications

References 0 publications

Solvent network at the transition state in the solvolysis of hindered sulfonyl compounds

Solvent network at the transition state in the solvolysis of hindered sulfonyl compounds

Heat capacity of activation for the hydrolysis of methanesulfonyl chloride and benzenesulfonyl chloride in light and heavy water

Solvolysis of Sulphonyl Halides. IV. The Hydrolysis of Some Substituted Aliphatic Sulphonyl Chlorides and of Ethanesulphonyl Bromide in Aqueous Dioxan

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