Acetylation of aromatics over acid zeolites: Seeking a viable alternative to Friedel-Crafts catalysts*
Matteo Guidotti1, Jean-Marie Coustard2, Patrick Magnoux2, and Michel Guisnet2
1CNR Institute of Molecular Sciences and Technologies, via Venezian 21, 20133 Milan, Italy; 2Department of Basic and Applied Sciences, University of Poitiers, UMR CNRS 6514 and 6503, 40 av. du Recteur Pineau, 86022 Poitiers Cedex, France
Abstract: Three acid zeolites (H-BEA, H-FAU, and H-MWW) were used as catalysts for acetylation in batch reactors with acetic anhydride of five aromatic compounds (benzenic and naphthalenic derivatives). The substrate reactivity is mainly governed by electronic factors (the nature of the substituents and degree of ring activation), but steric effects also play a relevant role when the reaction takes place in a narrow micropore system. In general, H-FAU was the most active catalyst, whereas with H-BEA remarkable steric constraints were observed. H-MWW showed good stability toward deactivation and an interesting activity of the sites located on the external surface.
Keywords: zeolites; acetylation; acetic anhydride; H-BEA; H-FAU; H-MWW; aromatic ketones; heterogeneous catalysis.
*Pure Appl. Chem. 79, 1831-2100. An issue of reviews and research papers based on lectures presented at the 1st International IUPAC Conference on Green-Sustainable Chemistry, held in Dresden, Germany, 10-15 September 2006.