Preparation of bis(polyfluoroalkyl)cyclopentadienes, new highly fluorophilic ligands for fluorous biphase catalysis

Bis[2-(perfluoroalkyl)ethyl]cyclopentadienes were synthesized from lithium [2-(perfluoroalkyl)ethyl]cyclopentadienides and 2-(perfluoroalkyl)ethyl triflates as mixtures of four regioisomers, structure of which was determined by 1H and 13C NMR spectroscopy. 2-(Perfluoroalkyl)ethyl triflates are useful fluorinated building blocks that can be employed in the synthesis of functionalised polyfluorinated substances.