“…[49][50][51] Thenet pathway from 1 is adouble CÀFactivation of the fluoroalkenes leading to new fluorinated allenes.I nt he case of 3 and 4a,the second CÀFbond cleavage step is extremely slow.At353 K, 4a has ahalf-life of approximately 6days.For comparison, the first C À Fbond cleavage is fast and 4a forms from 1 and hexafluoropropene within minutes at 298 K. A further reaction between 1 and 1,1,1,4,4,4-hexafluoro-2butene (10 equiv;HFO-1336-mzz) did not allow the isolation of an ew organoaluminium compound but instead led to the formation of an s-trans isomer of 1,1,4,4-tetrafluorobutadiene and 1-F 2 . [52,53] While the unambiguous assignment of this pathway will have to await afull mechanistic study,itappears that, in this case,t he rate of the second CÀFb ond cleavage step is either similar to or faster than the first, possibly due to the ease of 1,3-diene formation over allene formation, leading directly to the organic product.…”