Friedel–Crafts catalysis using sol–gel derived supported reagents

Metal diketonate modified mesoporous aluminosilicates

Abstract

Aluminosilicates have been prepared from aluminium tri-sec-butoxide and tetraethyl orthosilicate in butanol incorporating transition metal pentane-2,4-dionate complexes, which on calcination give active Friedel–Crafts alkylation catalysts having texturalmesoporosity. Addition of β-diketonates to the aluminosilicate sol–gel results in complexation to aluminium which, on calcination,generates a mesoporous aluminosilicate with increased surface area and pore volume. This provides a suitable framework upon which zinc chloride may be supported at higher loadings than for either the unmodified material or K10, the support for the commercial catalyst Clayzic, to give materials with significantly higher catalytic activity in a Friedel–Crafts alkylation reaction.