Preparative-scale one-pot syntheses of hexafluoro-1,3-butadiene

Hexafluoro-1,3-butadiene, with its negligible global warming potential, is required in quantities for application in plasma dielectric etching in semiconductor industry and as gaseous microbubble suspension contrast agents in diagnostic ultrasound imaging. Three efficient protocols for the preparation of perfluoro-1,3-butadiene in 62–70% overall yields have been described. They involve the coupling of (1) iodotrifluoroethylene (ITFE) with activated copper, (2) trifluorovinylzinc bromide in the presence of copper (II) or iron (III) salts and (3) trifluorovinylzinc chloride, prepared from 1,1,1,2-tetrafluorethane (HFC 134a) in the presence of copper (II) or iron (III) salts.