Nucleophilic Aromatic Substitution

Effects of the solvent, temperature, and nucleophile nature on the selectivity of nucleophilic substitution in 1-chloro-3,4-dinitrobenzene were studied, and optimal conditions were found for the synthesis and isolation of particular products.

Specific features of nucleophilic substitution in 1-chloro-3,4-dinitrobenzene

Nucleophilic Aromatic Substitution: An Update Overview

The reaction of O-(2,4-dinitrophenyl) cyclopentanone oxime with four primary alkylamines and a secondary arylamine, pyrrolidine, in benzene has been investigated. In pyrrolidinolysis, a third order dependence on [amine] has been observed, which has been explained on the basis of a cyclic transition state. The aminolysis with primary alkyl amines shows a normal dependence of second order on [amine].

Kinetic studies on the aminolysis of O-(2,4-dinitrophenyl)-cyclopentanone oxime in benzene

The effect of various hydrogen-bond acceptors on the reactions of 1-chloro- and 1-fluoro-2,4-dinitrobenzenes with morpholine in benzene at 30°C has been investigated. The reaction of the chloro substrate is not base-catalysed and the additives produced no acceleration in the concentrations employed. The reaction of the fluoro substrate is base-catalysed. The addition of hydrogen-bond acceptors frequently leads to accelerations which vary linearly with the concentration of the acceptor. An approximately linear relationship exists between the logarithm of the slope of these correlations and the hydrogen-bonding parameter pkHB. These effects are interpreted as electrophilic catalysis, by the heteroconjugates of the acceptors with the conjugate acid of morpholine, of the ratedetermining decomposition of the intermediate in these reactions.

Goddy N. Onuoha

Papers

Mechanism of aromatic nucleophilic substitution in aprotic solvents

Mechanism of Aromatic Nucleophilic Substitution in Aprotic Solvents.