A facile route to tetrafluoroallene

Organometallic chemistry of fluorinated propadienes and butadienes

“…The manganese oxygen distance of 1.735 Å is in the same range as observed for oxo bridged species containing classical ligands [45]. The 1 H, 19 F and 13 C NMR spectra exhibit broad resonances with temperature dependant chemical shifts due to the paramagnetism of the compound.…”

“…Tetrafluroallene, first prepared by Jacobs and Bauer [16], is even less studied. Again that might be due to the lack of an efficient synthesis [17,18] until 1995 when Burton et al published an easy high yield synthesis from a commercially available starting material (Scheme 1) [19]. The solid state structures of 1,1-difluoroallene and tetrafluoroallene were determined recently by X-ray diffraction at low temperature including an experimental charge density determination of the first [20].…”

Reactions of Fluoroalkenes with an Aluminium(I) Complex

“…While 2-E, 2-Z, 4b,a nd 5 were found to be stable at high temperatures for prolonged periods of time (353 K; > 1week), both 3 and 4a fragmented when heated to 353 K. Theo rganic fragments were identified as 1,1-difluoroallene (from 3)and tetrafluoroallene (from 4a); both form alongside the expected aluminium difluoride 1-F 2 ,w hich has also been isolated and fully characterised (Scheme 4). [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.…”

Organometallic Chemistry of Fluorinated Allenes

“…Tetrafluroallene, first prepared by Jacobs and Bauer in 1959, has been even less studied 15. Again, that might be due to the lack of an efficient synthesis16, 17 until 1995 when Burton et al published an easy high‐yield synthesis from a commercially available starting material 18. During our studies on the fluorination effects on small organic molecules,19 we have started to investigate the chemistry of 1,1‐difluoroallene and tetrafluoroallene.…”