During the formation of 2a, mixtures of E/Z-fluoroalkenes could be observed as reaction intermediates. It was assumed that the formation of the difluoroalkane products occurs by two sequential HF transfer events, the first of which generates a mixture of alkene isomers. Independent synthesis of (Z)-6-fluorododec-6-ene and exposure to the catalytic conditions resulted in formation of 2i in 60 % yield alongside (E)-6-fluorododec-6-ene in 8% yield, confirming the Z-fluoroalkene as a potential reaction intermediate. Comparison of the local energy barriers for the key steps via TS-1, TS-2 and TS-3 suggests that the hydrodefluorination step should be turnover-limiting for the catalytic sequence. Moreover, the lowest barrier and least exergonic step is associated with TS-3. In the reverse direction, this barrier is G ‡ (298 K) = 28.5 kcal mol -1 , lower than the global activation energy for catalysis. The calculations suggest that the conversion of 1-fluoropropene to 2,2-difluoropropane should be reversible. Such reversibility would offer the opportunity to establish HF shuttling between these substrates. In line with these calculations, the reaction of 2i with 1heptyne led to the formation of 2a along with the fluoroalkene 3. Similarly, a comproportionation type reaction of 2i with dodec-6-yne resulted in formation of 3 as an 4:1 mixture of Z:E isomers in 81% yield (Figure ). BF3-mediated isomerization of fluoroalkenes has been observed previously and the Z-isomer is expected to be the thermodynamically more stable product. 19 In summary, we report a new method to transfer HF between fluoroalkanes and alkynes. The reaction operates with a simple commercial catalyst (BF3-OEt2) and can be performed directly in borosilicate glassware or FEP reaction vessels without the need for handling toxic and corrosive HF based reagents. We demonstrate that the conversion of fluoroalkene intermediates into difuoroalkanes is reversible, establishing the first true HF shuttle. Our method holds promise as a means for the chemical recycling of fluorocarbons we are continuing to investigate applications in both synthesis and materials science.