Synthesis of Cyclopentadiene Ligands with Fluorinated Substituents by Reaction of Cobaltocene with Fluoroalkenes

The hitherto difficult introduction of fluorinated and perfluorinated substituents onto cyclopentadienes is possible by the simple reaction of cobaltocene with fluorinated olefins(CF 2 =CFX; X = I, Br, Cl, CF 3 ). Two structurally different products, that is, a mononuclear complex and a dinuclear complex, are formed. Reaction of cobaltocene with iodotrifluoroethene yields η 5 ‐cyclopentadienyl‐η 4 ‐trifluorovinylcyclopentadienecobalt and cobaltocenium iodide. Reaction of cobaltocenium salts with hexafluoropropene and trifluorovinyllithium represents an alternative high‐yielding synthesis of the corresponding compounds. The molecular structures of three compounds were elucidated by using single‐crystal X‐ray diffraction.