Aromatic nucleophilic substitution (s_nar) reactions of halo‐substituted dinitrobenzene in liposome reaction media: Effect of reaction medium and role of halogen leaving group

Abstract

S N Ar reactions constitute an important pathway for the synthesis of many crucial organic derivatives from polyhaloaromatic compounds. The sluggish nature of the reaction in many cases makes it a challenging pathway and limits its potential applications. In the present report, liposomes have been used as model membrane systems to study nucleophilic substitution reactions of halosubstituted dinitrobenzene with morpholine. The results show an interesting dependence of the reactivity on the size and composition of liposomes. The extent of rate acceleration in liposomes is strongly dependent on the identity of the halogen which undergoes the substitution-for example, chlorosubstituted aromatic compounds show the most sensitivity to the presence of lipsomal reaction media. The observed behavior correlates with the reported reactivity of halobenzenes while revealing interesting details which may be critical in harnessing the reactivity of less reactive substrates. The results explore the viability of employing liposomes as promising alternatives for synthetic protocols.

Anion-Afforded Functions of Ionic Metal–Organic Frameworks: Ionochromism, Anion Conduction, and Catalysis

“…As can be seen, the yield with 1-Cl increases very slowly with time and remains below 20% even after 14 h. By contrast, 1-I leads to much more rapid conversion, which is almost completed after 12 h. The conversion with 1-Br lies between. The different activities of these IMOFs are consistent with the nucleophilicity and leaving ability of the halide ions, both increasing from Cl – to I – . A strongly nucleophilic ion is conducive to the ring-opening process by attacking a carbon atom in the epoxide ring, and a good leaving agent can facilitate the ring-closing process of the bromoethyl monocarbonate intermediate .…”

“…The different activities of these IMOFs are consistent with the nucleophilicity and leaving ability of the halide ions, both increasing from Cl − to I − . 59 A strongly nucleophilic ion is conducive to the ringopening process by attacking a carbon atom in the epoxide ring, and a good leaving agent can facilitate the ring-closing process of the bromoethyl monocarbonate intermediate. 20 The CO 2 adsorption isotherms of 1-Cl, 1-Br, and 1-I were measured at 273 and 298 K (Figure S16a).…”