Hydrogen- and Fluorine-Bridged Disilyl Cations and Their Use in Catalytic C−F Activation

The hydrogen-bridged disilyl cation 6 with an 1,8-naphthalenediyl backbone was synthesized
and was characterized by NMR spectroscopy and X-ray crystallography, supported by quantum mechanical
computations. The SiHSi linkage is symmetrical, corresponding to a single minimum potential, and the
structural parameters are in agreement with the presence of a two electron−three center bond in 6.
Treatment of disilyl cation 6 with alkyl fluorides yields the disilylfluoronium ion 10. The SiFSi group in the
disilyl fluoronium ion 10 is symmetrical with an average SiF bond length of 175.9(8) and a bent angle β =
130°. Both cations catalyze the hydrodefluorination reaction of alkyl and benzyl fluorides to give alkanes.