Formation of perfluoro

The possibility of obtaining real improvements in the industrial production of perfluorooctanoic acid by using perfluorohexyl acetyl chloride in place of octanoyl chloride as starting material has been investigated [136]. In particular, the effect of blocking the formation of cyclic ethers on the yield of the perfluoro-acid was examined this was, however, less than expected due to the increased formation of perfluoro- -heptane. 

Cyclization products have also been observed when perfluorodienes are heated with fluoride ion. While perfluoropenta-1,4-diene (32) gives perfluoropent-2-yne in 98% yield when passed over cesium fluoride at 240"C, the use of sodium fluoride at 440°C results in the formation of perfluoro(1 -methylcyclobutene) (33) in 58 % yield, together with perfluorocyclopen-tene (10%) and perfluoropent-2-yne (27%).24... 

Aryl-substituted aliphatic compounds show additional elimination reactions in the side chain resulting in perfluoroalkenylaromatics, e. g. formation of perfluoro(2-phenylpropene) (3).127,128... 

Perfluoropiperidine derivatives are transformed129-131 to the corresponding per-fluoropyridine compounds, e.g. formation of perfluoro(2-methylpyridine) (6).131... 

Hydrolysis of perfluoro-3-isopropyl-4-methylpentenyl-2-sulfenyl chloride 34 having a mobile allyl fluorine atom ends with the formation of perfluoro-2,4,4-trimethyl-3-isopropylthiete 35 (yield 30%) (89IZV1380). The reaction occurs via the intermediate formation of the derivative of sulfenic acid 36 due to the high mobility of the allylic fluorine atom. 

In this case, a mixture of cis- and ra s-perfluoro-4,5-dihydro-2,3,4,5-tetramethyl-4-ethylfurans is obtained. This is a general reaction, which also works with other perfluoroolefins and alcohols. For example, when the tetrafluoroethylene pentamer reacts with allyl alcohol in the presence of bases, the initial reaction is nucleophilic addition at the multiple bond, forming olefin 44, followed by the formation of perfluoro-4-ethyl-2,3,4,5-tetramethyl-4,5-dihydrofuran 45 in the presence of KF (87ASCC31). 

An analogous reaction is the formation of perfluoro(l-vinylazepane) (14), perfluoro(l,4-divinylpiperazine) (15), and various perfluoro(vinylamines) 16. ... 

Tetrafluoro-l,2,3-trithiolane 189 was synthesized by the reaction of sulfur with tetrafluoroethene. At elevated temperature, tetrafluoroethylene reacts with the complex S4(Sb2Fi 1)2 with the formation of perfluoro-3,5-dimethyl-3,5-diethyl-1,2,4-trithiolane 190. ... 

Hayashi, E. Abe, T. Nagase, S. Formation of perfluoro(A-alkyl lactams) by the reaction of perfluoro(A-alkyl cyclic amines) with fuming sulfuric acid. Chem. Lett. 1985 (3), 375-376. 

Publications have appeared that deal with the following (i) the enthalpy of formation of perfluoro-iNW-difluoromethylamine (prepared by KF-catalysed direct fiuorination of KSCN decomposition of the fluoroamine to CF, Na, and Fa had to be triggered with a NF3-C2N2 mixture)... 

The formation of perfluoro-iVAT-dichloroamines in the above manner... 

Additionally, they also indicated a possible mechanism for the formation of perfluoro-2-butene from TFE, presented in Scheme 5.10. 

An isocyanide complex, R2NC02Cu(CNBut) (31 R = Et, 1.4) was isolated from reaction of CuOBu, Et2NH, and CO2. Treatment of (31) with R X provide urethanes. Ability of Cu X to promote urethane formation from R2NH, CO2, and R X decreases in the sequence X = OBu > OAc > Cl the presence of a ligand (in particular NCR) is necessary. Formation of perfluoro-phenyl-Au and isocyanide and carbene complexes are given in Scheme 6. 

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