The kinetics of nucleophilic bimolecular substitution reactions of γ‐functionalized allyl bromides with non‐substituted and p‐substituted sodium arenesulfinates has been studied. Both the structure of allyl bromides and nucleophilicity of arenesulfinate ions exerted a significant effect on the values of the kinetic parameters such as the second‐order rate constants k, activation energy EA, and changes in the entropy ΔS≠, enthalpy ΔH≠, and free energy ΔG≠ of the formation of the activated complex from reactants. Based on the evaluation of kinetic parameters, the reactants could be arranged, according to their decreasing reactivity in the SN2‐reactions as follows: p‐toluenesulfinate ion > benzenesulfinate ion > p‐chlorobenzenesulfinate ion and 4‐bromo‐2‐butenenitrile > 1,3‐ dibromopropene, respectively. Comparison was also made between the kinetic data obtained and some delocalization reactivity indexes for both the substrates and nucleophiles. The enthalpy–entropy compensation effect was observed for the reactions of sodium arenesulfinates with γ‐functionalized allyl bromides. Copyright © 2009 John Wiley & Sons, Ltd.

The kinetics of the addition of arenesulfinic acids to 4-substituted 2-nitroethenylarenes was studied by means of UV spectrophotometry. The effect of 4-substituting groups in benzenesulfinic acids, and the change in reactivity of nitroethylene system due to typical electron-donating and electron-withdrawing groups were investigated. The substituent effect on benzenesulfinic acid fits Hammett's equation, p-value at 298 K being -1.12 (r = 0.987). Kinetic studies were carried out at 288-308 K, and the activating energy and the enthalpy of activation were determined.

The nucleophilic addition reactions of both the non‐substituted and p‐substituted benzenesulfinic acids with 2‐chloro‐ and 2‐bromoacrylonitriles have been studied. The structures of the 3‐benzenesulfonyl‐2‐halogenopropanenitriles thus obtained were confirmed by microanalytical and spectral methods. The basic kinetic parameters of the reactions were determined and some local electronic descriptors concerning the reaction centers were calculated. For the interaction with benzenesulfinic acids, 2‐bromoacrylonitrile was found to have higher reactivity as a Michael acceptor than 2‐chloroacrylonitrile. The higher reactivity of 2‐bromoacrylonitrile is associated with the higher electrophilicity of its β‐carbon atom, which was proved by its pronounced acceptor delocalizability and increased reaction rate values with the corresponding benzenesulfinic acids.

The structure of p‐substituted phenyl 2‐nitrovinyl sulfones was studied through different spectral methods. It has been found that the nucleophilic substitution reactions of sodium phenylsulfinates with 1‐chloro‐2‐nitroethene occur stereospecifically. The formation of E‐isomers of this type of substituted phenyl vinyl sulfones was confirmed by FTIR and NMR spectroscopy. It was suggested that the E‐isomers formation was determined by the more stable conformation of the carbanionic intermediate as a result of intramolecular rotation around single Cα‐Cβ bond. This appears to be the product‐determining pathway during the interaction of sodium phenyl sulfinates with the highly activated substrate 1‐chloro‐2‐nitroethene.

1-Aryl-1-arylsulfonylethene derivatives have been prepared by the interaction of α-iodo-β-nitrostyrene with arenesulfinic acids. The structure of the products were confirmed by 1 H-NMR, IR, UV spectroscopy and elemental analysis. The kinetic studies indicated that the reaction took place via vinyl nucleophilic substitution mechanism. The principal kinetics and reaction parameters were determined.