Oxidative Additions of C−F Bonds to the Silanide Anion [Si(C2F5)3]

Compounds exhibiting main group elements in low oxidation states were found to mimic the reactivity of transition metal complexes. Like the latter, such main group species show a proclivity of changing their oxidation state as well as their coordination number by +2, therefore fulfilling the requirements for oxidative additions. Prominent examples of such main group compounds that undergo oxidative additions with organohalides R−X (R=alkyl, aryl, X=F, Cl, Br, I) are carbenes and their higher congeners. Aluminyl anions, which like carbenes and silylenes oxidatively add to strong σ‐bonds in R−X species, have been recently discovered. We present the first anion based upon a Group 14 element, namely the tris(pentafluoroethyl)silanide anion, [Si(C2F5)3]−, which is capable of oxidative additions towards C−F bonds. This enables the isolation of non‐chelated tetraorganofluorosilicate salts, which to the best of our knowledge had only been observed as reactive intermediates before. The tris(pentafluoroethyl)silanide anion, [Si(C2F5)3]−, digresses from the archetypical proclivity of nucleophilic substitutions, being capable of oxidative additions to aryl‐ and alkenylfluorides. Thus, tetraorganofluorosilicate salts devoid of chelating ligands, which had only been observed as reactive intermediates before, were isolated and fully characterized.