Acylation of anisole over mesoporous aluminosilicates

Mesoporous aluminosilicates have attracted much recent attention because of their potential use as versatile catalysts and catalyst supports, especially for large molecules, but their acidity is always much weaker than that of zeolites. They must be modified to enhance their acidity. Mesoporous Si-MCM-41 supported metal chloride catalysts[29] have shown high activity in the acylation of benzene by benzoyl chloride even in the presence of moisture in the reaction mixture. The time required for 54 % conversion of benzoyl chloride at 80 °C was 2.2 h in the presence of InC13/Si-MCM-41, against 18 h with H-BEA. 

A recent article reported the use of strongly acidic mesoporous aluminosilicates prepared from zeolite seeds in the acylation of anisole with octanoyl chloride.[30] The mesoporosity improving the transport of the reactants and the presence of strong acid sites lead to high conversion ( 90 %) and high selectivity (100 %). 

Chiche, B., Finiels, A., Gauthier, C., Geneste, P., Graille, J. and Pioch, D. Friedel-Crafts acylation of toluene and /7-xylene with carboxylic acids catalyzed by zeolites. J. Org. Chem., 1986, 51, 2128-2130. 

Bezouhanova, C. P. Synthesis of aromatic ketones in the presence of zeolite catalysts, Appl. Catal., A, 2002, 229, 127-133. 

---