Triflic acid-boron tris

Boron tris(trifluoromethanesulfonate). This triflate is obtained by reaction of BC1, with triflic acid in S02C1F at -78°. Distillation at reduced pressure provides a solid, m. p. 45°, b. p. 68-73°/0.5 mm. It is extremely hygroscopic, and is soluble m CRiC, CHjNOi, CH CN. Aluminum and gallium triflate are poorly soluble in the common solvents. All three triflates can function as Friedel-Crafts catalysts, but the boron triflate is the most effective as a soluble catalyst. ... 

Remarkably, nitronium salts have been shown to react even with methane under superacidic conditions.106 Nitronium hexafluorophosphate (NO2PF6.) reacts with methane, albeit in low yields, when the reaction is carried out in the presence of boron tris(triflate) in triflic acid (eq 63). 

Sodium borohydride in excess of triflic acid at low temperature provides" a highly efficient reductive superacid system, which was found effective for the reductive superacid isomerization of unsaturated polycyclic precursers to cage hydrocarbons in high yields (equation 25). The key to the success of the ionic hydrogenation system appears to be due to the in situ formation of boron tris(triflate), a highly superacidic Lewis acid. 

Boron tris (trifluoromethanesulfonate) was first prepared by Engelbrecht and Tschager in trifluoromethanesulfonic acid solution vide infra) as a conjugate acid system. Olah and co-workers have isolated B(OS02CF3)3 in pure form by treating boron trihalides (chlorides, bromides) with 3 equiv of triflic acid in Freon 113 or SO2CIF solution. 

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