Polar and steric effects in the homolytic amination of alkylbenzenes and biphenyl

Abstract

Partial rate factors for homolytic amination of alkylbenzenes and biphenyl by N-chloroamines have been determined in an acidic medium. The resulting polar effects are by far the highest ever observed in homolytic substitution and are of the order of magnitude of those in the common electrophilic reactions. The reaction is sensitive to steric and polar effects (conjugative and inductive, but not hyperconjugative), as previously observed for hydrogen absractions. The transition state of the reaction is discussed and a hypothesis is put forward on inductive and Baker–Nathan effects on electrophilic substitution.