Selective benzylation of benzene over alumina pillared clays

Abstract

Aluminium pillared clays prepared by partial hydrolysis method has been subjected to room temperature exchange with transition metals of the first series. The resulting materials exhibit a fine porous network of exception al stability as characterized by XRD, FTIR and NMR spectroscopy. EDX and surface area measurements indicate the presence of exchanged mewls attached to the pillars. Acidity of the pillared clay benefits from the insertion of transition metals. Benzylation of benzene occurs efficiently over these catalysts with 100% monoalkylated product selectivity. An extensive study or the reaction variables points towards a carbocation mechanism for the reaction. The reaction depends to a large extent on the number and avail ability of the Lewis acid sites.