Scandium(III) Trifluoromethanesulfonate Catalyzed Aromatic Nitration with Inorganic Nitrates and Acetic Anhydride

Abstract

The rare earth metal(III) trifluoromethanesulfonate (rare earth metal(III) triflate, RE(OTf)₃) was found to be an efficient catalyst for aromatic nitration with carboxylic anhydride–inorganic nitrate as the nitrating agent. In the presence of a catalytic amount of RE(OTf)₃, the nitration of substituted benzenes proceeded to afford the corresponding nitrobenzenes. Especially, scandium(III) trifluoromethanesulfonate (scandium(III) triflate, Sc(OTf)₃) is the most active catalyst among our tested Lewis acids. It was also found that acetic anhydride–Al(NO₃)·9H₂O is the most active nitrating agent in this system.