par Hinkens, Raymonde 
;Kaisin, Michel ;Grandjean, D.;Loos, Manon D. ;Nasielski, Jacques
Référence Bulletin des Sociétés chimiques belges, 97, 11-12, page (919-926)
Publication Publié, 1988
;Kaisin, Michel ;Grandjean, D.;Loos, Manon D. ;Nasielski, Jacques Référence Bulletin des Sociétés chimiques belges, 97, 11-12, page (919-926)
Publication Publié, 1988
Article révisé par les pairs
| Résumé : | Piperidine, cyclohexylamine, methoxide ion and para‐thiocresolate ion react with 2‐chloro‐3‐nitroquinoxaline 1 by selectively substituting the nitro group, in contrast to the behavior of most ortho‐chloronitroaromatics which loose halide when subjected to nucleophilic substitution reactions. This inversion is interpreted as being due to the lack of activation of the 2‐position by the nitro group in the 3‐position because of the low value of the π‐bond index between these two vertices. It is also suggested that the substitution by neutral reagents such as amines is strongly influenced by stabilizing interactions between the negatively charged nitro group and the ammonium moiety in the σ complex; this built‐in solvation may be responsible for inversions in the chemoselectivity between chloro and nitro nucleofugicities. Copyright © 1988 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim |
