Nitration of Strongly Deactivated Aromatics with Superacidic Mixed Nitric–Triflatoboric Acid (HNO₃/2CF₃SO₃H–B(O₃SCF₃)₃)

The nitration of various deactivated arenes (including methanesulfonyl-, nitro-, and polyhalobenzenes) was carried out in good yield with mixed nitric–triflatoboric superacid. For example pentafluorobenzene gave pentafluoronitrobenzene in 99% yield, nitrobenzene to m-dinitrobenzene in 92% selectivity with 85% overall yield, and methyl phenyl sulfone gave only the m-nitro isomer in 78% isolated yield. Thus the new nitrating system gives high regioselectivity and yields under generally mild reaction conditions. The reagent system is compatible with many functional groups of arenes.