title: Acylation and related reactions under microwaves. 4. Sulfonylation reactions of aromatics.
abstract: Solvent-free sulfonylation of benzene and its activated or deactivated derivatives were carried out under microwave (MW) irradiation and a catalytic amount of iron(III) chloride, which, under these conditions, is more active than other metallic salts. With more reactive and/or nonvolatile reagents (anisole, xylenes, mesitylene) expeditious conditions (short reaction time at constant MW power without control of the temperature) were used. With less reactive and/or low-boiling reagents (benzene, toluene, halobenzenes), the rise in temperature and the increase of reaction time were controlled either by sequential MW irradiation or by a temperature order. It was shown that MWs cause preferential interactions with polar species present in the reaction, especially the aryl sulfone and its FeCl3-complexed form. A MW nonthermal effect was not observed when identical temperature gradients were produced by classical heating and MW irradiation, and if reaction temperature was strictly controlled.
authors: Hétérochimie Fondamentale et Appliquée (UMR 5069 CNRS), Université Paul-Sabatier, 118 route de Narbonne, 31062 Toulouse, France.
authors: J
authors: J
authors: Marquié
authors: A
authors: A
authors: Laporterie
authors: J
authors: J
authors: Dubac
authors: N
authors: N
authors: Roques
authors: J R
authors: JR
authors: Desmurs