2,2,3,3-Tetrafluoronickelacyclopentanes Generated via the Oxidative Cyclization of Tetrafluoroethylene and Simple Alkenes: A Key Intermediate in Nickel-Catalyzed C–C Bond-Forming Reactions

Oxidative cyclization of tetrafluoroethylene (TFE) and ethylene with Ni(0) resulted in the formation of a five-membered nickelacycle. In the presence of PPh3 as an auxiliary ligand, the partially fluorinated five-membered nickelacycle was isolated and the structure was determined by X-ray analysis. This nickelacycle was found not only to react stoichiometrically with enones to give a cross-trimerization product but also to be a key reaction intermediate in the Ni(0)-catalyzed cotrimerization of TFE and ethylene, leading to 5,5,6,6-tetrafluoro-1-hexene.