Highly active Si-MCM-41-Supported Ga2O3 and In2O3 catalysts for Friedel-Crafts-type benzylation and acylation reactions in the presence or absence ofmoisture

Ga2O3 and In2O3 (which are amphoteric and basic in nature, respectively) su pported on mesoporous Si-MCM-41, or even on micro- or macroporous inert cat alyst carriers, are highly active and reusable catalysts for the benzylatio n of benzene and acylation of aromatic compounds, even in the presence of m oisture. Moisture has a beneficial effect, more particularly for the acylat ion reaction. It causes an increase in the reaction rates for both the reac tions and also a large increase in the induction period for the benzylation reaction but not for the acylation. The induction period is due to the pre sence of moisture adsorbed on the catalyst, which is to be replaced by the reactant(s) to start the catalytic reaction. (C) 2000 Academic Press.