Under these conditions some pentafluorobenzene was formed (35%) as a result of hydrodebromination, but the reaction was sluggish, due to the slow reactivity of (41%). Addition of fluoride to the system appears to have significantly increased the rate of hydrodebromination, which was then followed by HDF of the pentafluorobenzene product (c.f. Scheme 2, 8b). This is consistent with the proposed importance of hydrosilicate anions in this system.