Consecutive C–F bond activation and C–F bond formation of heteroaromatics at rhodium: the peculiar role of FSi(OEt)(3)

C–F activation of 2,3,5,6-tetrafluoropyridine at [Rh{Si(OEt)(3)}(PEt(3))(3)] (1) yields [Rh{2-(3,5,6-C(5)F(3)HN)}(PEt(3))(3)] (2) and FSi(OEt)(3), but in an unprecedented consecutive reaction FSi(OEt)(3) acts as a fluoride source to give [Rh(4-C(5)F(4)N)(PEt(3))(3)] (4) by regeneration of the C–F bond and C–H activation. Analogous refluorination steps were observed for other 2-pyridyl rhodium complexes. NMR spectroscopic studies revealed a delicate balance between the feasibility for C–F bond formation accompanied by a C–H activation and the occurrence of competing reactions such as hydrodefluorinations induced by the intermediary presence of H(2).