Consecutive C-F Bond Activation of Hexafluorobenzene and Decafluorobiphenyl

The reaction of [Ni-2(iPr(2)Im)(4)(COD)] (1) {iPr(2)Im = 1,3-bis(isopropyl)imidazolin-2-ylidene} with hexafluorobenzene and decafluorobiphenyl results at room temperature in the formation of the products of a C-F bond activation reaction, i.e. [Ni(iPr(2)Im)(2)(F)(C6F5)] (2) and [Ni(iPr(2)Im)(2)(F)(C12F9)] (4). The reactions of 2 and 4 with 1 or the reactions of hexafluorobenzene and decafluorobiphenyl with 1 equiv. or excess of dinuclear 1 (stoichiometric ratio nickel/substrate > 2:1) at higher temperatures afford the complexes of a consecutive C-F bond-activation reaction, [1,4-{Ni(iPr(2)Im)(2)(F)}(2)(C6F4)] (3) and [4,4'-{Ni(iPr(2)Im)(2)(F)}(2)(C12F8)] (5). Complexes 3 and 5 cleanly react in THF at room temperature with chlorotrimethylsilane and (isopropyl)(trimethylsilyl)selenane under elimination of fluorotrimethylsilane to yield the corresponding chloro and selenolato complexes [1,4-{Ni(iPr2Im) 2(X)} 2(C6F4)] [X = Cl (6), iPrSe (7)] and [4,4'-{Ni(iPr(2)Im)(2)(X)}(2)(C12F8)] [X = Cl (8), iPrSe (9)].