A series of trifluoromethyl-substitutued arenes were studied in their reactions with Brønsted superacids. The products from these reactions suggest the formation of reactive electrophiles, such as carbocations, acylium cations, or equivalent electrophilic species. As such, Friedel-Crafts type reactions occur between these species and arene nucleophiles. NMR studies were done and the results suggest the formation of an acyl group from the trifluoromethyl groups in superacid.

1,2-Indandione reacts efficiently with arenes to give 2,2-diaryl-1-indanones by the hydroxyalkylation reaction. The Brønsted superacid CF3SO3H (triflic acid) is an effective catalyst for these condensation reactions. The requisite 1,2-indandiones were prepared from the 1-indanones.

The hydroxyalkylation reaction has been used to condense benzocrown ethers with various aldehydes and ketones. The condensation reactions are catalyzed by triflic or sulfuric acid. The products from the reactions are bis(benzocrown ethers) and they are formed in good yields (42-98%, 13 examples).

In the presence of benzene, a mixture of benzophenones and triarylmethanol derivatives is formed in most cases.

Superacid-Promoted Hydroxyalkylation of 1,2-Indandiones. -2,2-Diaryl--1-indanones (III) are efficiently obtained by TfOH-promoted condensation of 1,2-indandiones with arenes. -(TRACY, A. F.; ABBOTT, M. P.; KLUMPP*, D. A.; Synth. Commun. 43 (2013) 16, 2171-2177, http://dx.