A T-shaped Ni[κ2-(CF2)4-] NHC complex: Unusual Csp3-F and M-CF bond functionalization reactions

Abstract

A T-shaped octafluoronickelacyclopentane-NHC complex is prepared and characterized. While the solid-state structure includes a weak isopropyl-CH3 agostic interaction, the reactivity of this complex with Lewis- and Brønsted acids is clearly enhanced by its low coordination number. Reaction with Me3SiOTf, for example, yielded a rare metal-heptafluorocyclobutyl complex whereas carboxylic acids gave substitution at the α-carbon and/or Ni-CF bond protonolysis to afford thermally robust 4H-octafluorobutyl Ni complexes.