A Linear Solvation Energy Relationship Study for the Reactivity of 2-(4-Substituted Phenyl)-cyclohex-1-enecarboxylic, 2-(4-Substituted Phenyl)-benzoic, and 2-(4-Substituted Phenyl)-acrylic Acids with Diazodiphenylmethane in Various Solvents

Abstract

The reactivities of 2-(4-substituted phenyl)-cyclohex-1-enecarboxylic acids, 2-(4-substituted phenyl)-benzoic acids, and 2-(4-substituted phenyl)-acrylic acids with diazodiphenylmethane in various solvents were investigated. To explain the kinetic results through solvent effects, the second-order rate constants of the examined acids were correlated using the Kamlet-Taft solvatochromic equation. The correlations of the kinetic data were carried out by means of multiple linear regression analysis, and the solvent effects on the reaction rates were analyzed in terms of initial and transition state contributions. The signs of the equation coefficients support the proposed reaction mechanism. The solvation models for all investigated carboxylic acids are suggested. The quantitative relationship between the molecular structure and the chemical reactivity is discussed, as well as the effect of geometry on the reactivity of the examined molecules.