Benzylation of benzene by benzyl chloride over iron mesoporous molecular sieves materials

The alkylation of benzene with benzyl chloride has been investigated over a series of iron-containing mesoporous silicas with different Fe contents. These materials (Fe-HMS-n) have been prepared at room temperature using a route based on hydrogen bonding and self-assembly between neutral primary amine micelles (S-0) and neutral inorganic precursors (I-0). They have been characterized by chemical analysis, BET, XRD, and UV-vis spectroscopy. The mesoporous Fe-containing materials were very active benzylation catalysts with almost 100% selectivity to monoalkylated product and showed excellent stability. The kinetics of the benzene benzylation over this catalyst have been thoroughly investigated. A mechanism in which the reaction could be initiated by an oxidation of benzyl chloride with formation of a charge transfer complex is proposed. (C) 2003 Elsevier Inc. All rights reserved.