A free boratriptycene-type Lewis superacid.

Bicyclic pyrazabole-bridged ferrocenes with BH groups at their bridgehead positions were prepared from [Li(thf)][1,1'-fc(BH)] and pyrazole or 3,5-dimethylpyrazole in the presence of MeSiCl (1 or 1Me, respectively; 1,1'-fc = 1,1'-ferrocenylene); MeSiH and H are released as byproducts. Treatment of 1 or 1Me with 1 eq. of the hydride scavenger [PhC][B(CF)] afforded the borenium salts [2][B(CF)] (72%) and [2Me][B(CF)] (77%).