Some Studies on the Reversibility of the Association Step in S_RN 1 Reactions

Abstract

The association step in S_RN1 reactions, in which p- nitrobenzylic radicals are trapped by acinitronate ions or the anions from β- keto esters, is demonstrated to be effectively irreversible under the normal conditions of the S_RN1 reaction. The dissociation [i.e. fragmentation of the C(α)-C(β) bond] of C- alkylates [e.g. (2) or (3)] formed from aci - nitronates and p- nitrobenzylic substrates appears to take place in a process involving transfer of two electrons and not through dissociation of radical anions.