A variety of 2-oxazolines are found to react with arenes in superacidic triflic acid, CF3SO3H. It is proposed that the 2-oxazolines are protonated twice in triflic acid and the resulting intermediates undergo ring-opening reactions to produce reactive, dicationic species. These superelectrophiles are capable of reacting with benzene and o-dichlorobenzene in high yields by Friedel–Crafts type reactions.
