Amination by nucleophilic substitution and addition in solution: Substituents effect on changes in activation parameters

Changes in the activation parameters of amination along mechanisms S _N 2, S _N Ar, Ad _N and in reactions with acyl group transfer may serve as an additional investigation method for these reactions in solution. The approximation utilizes the substituents effect in benzene and pyridine derivatives on the changes in the activation parameters ΔX ^≠ (X = H, S, G) in the framework of equations of Hammett’s type for the estimation of the resulting reaction constants δΔX ^≠. The single linear dependences of the reaction constants of internal enthalpy δΔH _int ^≠ on the reaction constants δΔG ^≠ and Hammett’s ρ show that the substituents effect in the leaving and non-leaving groups and in the nucleophiles on the amination mechanisms is governed by the δΔH _int ^≠ , when unique stage of the process determines its rate.