Catalytic Friedel-Crafts Acylation and Benzoylation of Aromatic Compounds Using Activated Hematite as a Novel Heterogeneous Catalyst

Catalytic Friedel-Crafts acylation of benzene and unactivated benzenes such as chlorobenzene and nitrobenzene have been successfully carried out using activated hematite (alpha-Fe2O3) as a new, heterogeneous and green catalyst. Sonication of neat alpha-Fe2O3 in a water bath under air atmosphere at room temperature followed by heating at 200 degrees C, dramatically increase the activity of alpha-Fe2O3. With the catalyst loading as low as 5.0 mol%, a wide variety of benzene derivatives were easily converted into the corresponding acylated products in a clean and high-yielding acylation reaction. It was found that the activated alpha-Fe2O3 could be efficiently recycled and reused several times by simple washing with ethyl acetate, this cannot be attained with most of the traditional catalysts.