Is Selective Monosubstitution of Dihalides via SRN1 Reaction Feasible? An Electrochemical Approach for Dichloroarenes

Article abstract of DOI:10.1021/jo00106a009

1,4-Dichlorobenzene and dichloropyridines undergo S_RN1 reaction with various nucleophiles upon electrochemical initiation.Substitution can compete with reduction only when indirect electrolyses at low current are performed.Selective formation of monosubstitution products is observed when the nucleophiles used behave as electron-donating groups when attached to the aromatic moiety, a situation which is just the opposite of what had been observed when the same reactions were initiated photochemically.This surprising difference in behavior can be rationalized in terms of different capabilities of both activation methods to generate the key monosubstitution anion radical, ArNuX(.-).Kinetic and thermodynamic data concerning the reactivity of dichloroarenes in such processes are presented and discussed.