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

A new inorganic polymer, silica-supported polytrifluoromethanesulfosifoxane solid superacid (SiO2-Si-SCF3), has been prepared. The acid strength of superacid (Ho < -13.76) is higher than that of 100% H2SO4 (Ho = -11.9). It was found that SiO2-Si-SCF3 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. (C) 2000 Elsevier Science B.V. All rights reserved.