Perfluoro-heptene

Several poly(fluorinated olefins) are used in practice. These include poly(vinyl fluoride), poly(vinylidene fluoride), poly(trifluoroethylene), poly(tetrafluoroethylene), and other fluorinated polyolefins such as poly(perfluoro-heptene) or poly(perfluoro-propylene). Poly(vinyl fluoride) with the general formula [-CH2CHF-]n and CAS 24981-14-4 is less common than its chlorinated analog, but still has numerous practical applications, mainly in coatings. Upon heating, the polymer begins losing HF at about 350° C with formation of double bonds in the carbon chain. At about 450° C the backbone of the polymer... 

Miller et al. [9] hypothesized rules on the regioselectivity of addition from the study of the base-catalyzed addition of alcohols to chlorotnfluoroethylene. Attack occurs at the vinylic carbon with most fluorines. Thus, isomers of dichloro-hexafl uorobutene react with methanol and phenol to give the corresponding saturated and vinylic ethers The nucleophiles exclusively attack position 3 of 1,1-dichloro-l,2,3,4,4,4-hexafluoro-2-butene and position I of 4,4-dichloro-l,l,2,3,3,4-hexafluoro-1-butene [10]. In I, l-dichloro-2,3,3,4,4,4-hexafluoro-l-butene, attack on position 2 is favored [J/] (equation 5) Terminal fluoroolefms are almost invariably attacked at tbe difluoromethylene group, as illustrated by the reaction of sodium methoxide with perfluoro-1-heptene in methanol [/2J (equation 6). 

Hexafluoropropene and sulfur react at 425 °C in the vapor phase to give hexafluorothioacetone and its dimer [/]. In dimethylformamide, it reacts with potassium fluoride and sulfur to give hexafluorothioacetone dimer, which further reacts with hexafluoropropene to give the E and Z isomers of perfluoro-2,4,6-tris(trifluoromethyl)-5-thia-3-heptene [2] (equation 1). 

Cyclohexene-l-one, methyl vinyl ketone, phenylacetylene, diphenylacety-lene, benzaldehyde, perfluoro-l-heptene, and cyclohexene were found to not be effective dienophiles for the reaction. Only polymeric o-xylylene products were seen in the reaction mixture. In addition, no cycloadduct was produced by using / -benzoquinone as the dienophile. Only hydroquinone and a,a -diiodo-o-xylene were recovered. The hydroquinone presumably results from the reduction of benzoquinone by nickel. Since sodium iodide is known to react with dibromo-o-xylene to give diiodo-o-xylene [112], the diiodo-o-xylene could result from the reaction of unconsumed dibromo-o-xylene with lithium iodide which is present in the reaction flask. These results are analogous to those reported in a similar reaction by Scheffer [113], where the use of zinc metal and ultrasound gave only hydroquinone and a quantitative yield of the unreacted dibromo-o-xylene. 

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