Solid superacid, silica-supported polytrifluoromethanesulfosiloxane catalyzed Friedel–Crafts benzylation of benzene and substituted benzenes

Abstract

A new inorganic polymer, silica-supported polytrifluoromethanesulfosiloxane solid superacid (SiO 2–Si–SCF 3), has been prepared. The acid strength of superacid (Ho<−13.76) is higher than that of 100% H 2SO 4 (Ho=−11.9). It was found that SiO 2–Si–SCF 3 could catalyze Friedel–Crafts benzylation of benzene and substituted benzenes with benzyl alcohol under relatively mild experimental conditions. Reactions are very clean, water is the only by-product of the reaction. The yields amounted to 97–100%, respectively. The selectivity was influenced by catalyst concentration, reaction time and toluene/benzyl alcohol molar ratios.