Boron trifluoride etherate as a catalyst in acylation of ferrocene

Ferrocene was acylated in acetic or propionic anhydride, in presence of boron trifluoride etherate giving acetyl ferrocene ( 1 ) (in quantitative yields) or propionyl ferrocene ( 2 ) (in high yields). A more general procedure is based on the reaction between ferrocene and carboxylic anhydrides or acyl halides in presence of ascorbic acid. Acetyl, propionyl, benzoyl, anisoyl and 3-phenyl propionyl ferrocenes ( 1 – 5 ) were obtained in moderate to high yields.