The Friedel-Crafts acylation of aromatic compounds with carboxylic acids by the combined use of perfluoroalkanoic anhydride and bismuth or scandium triflate

Aromatic ketones were synthesized by solventless Friedel-Crafts acylation of anisole, mesitylene, xylenes, and toluene with acetic acid and benzoic acid in the presence of trifluoroacetic anhydride by use of bismuth or scandium triflate at 30 degreesC. Toluene, benzene, and even deactivated substrate such as chlorobenzene were benzoylated by the combined use of heptafluorobutyric anhydride and bismuth triflate at 75-100 degreesC. The catalyst could be easily recovered and reused repeatedly for the reaction. (C) 2004 Elsevier Ltd. All rights reserved.