Polyvalent-metal salts of heteropolyacid as efficient heterogeneous catalysts for Friedel–Crafts acylation of arenes with carboxylic acids

Polyvalent-metal (Ti4+, Fe3+, Sn4+, Bi3+, Ru3+) salts of dodecatungstophosphate act as effective heterogeneous catalysts for Friedel–Crafts acylation of aromatics with carboxylic acids. The Fe3+ salt shows high yields and the highest turnover number (2500) reported to date and can be reused without loss of activity, providing one of the greenest route to aromatic ketones.