“…The early synthesis of 1,1,4,4-tetrafluorobuta-1,3-diene by radical addition of 1-iodo-2,2-difluoroethene to 1,1,-difluoroethene followed by elimination of hydrogen iodide gives only low yields of the dien [36]. Using palladium catalyzed C-C coupling reactions [37], an effective synthesis of 1,1-difluorobuta-1,3-diene [38], 1,1,4,4-tetrafluorobuta-1,3-diene [38], pentafluorobuta-1,3-diene [38] and hexafluorobutadiene [38] could be developed using 2,2-difluoro-1-iodoethene and bromotrifluoroethene, respectively, via the zinc [39] and tin [40] compounds, respectively. 1,1,2-Trifluorobuta-1,3-diene was prepared by dihydrohalogenation of commercially available 1,1,2-trifluoro-4-bromo-but-1-ene [41].…”