Fluoroalkene chemistry

Fluoroalkene chemistry

“…Only a trace of bis-substituted product was observed in the experiment, in contrast to the situation with aromatic thiols, which gave mainly all bis-product, due to lower acidity of the cysteine ester which renders the double bond of the mono product less reactive; the a-carbanion is stabilised less by aliphatic thio groups than by aromatic thio groups in line with relative acidities (pK a values for Nacetylcysteine isopropyl ester and the arylthiols were found to be 10.8 and 8.2-7.6, respectively). Two molar equivalents of thiol gave bis vinyl product 14 identical to a specimen made earlier from hexafluorocyclobutene [20].…”

“…Vinyl substitution products have been obtained from 1,2-dichlorodifluorocyclopropene and potassium thiocyanate [9] and alkenes E-G [10][11][12][13][14][15][16][17] and HFCB [18][19][20] with aromatic and aliphatic thiols. Several conclusions can be drawn: (a) sulfur nucleophiles are more reactive than nitrogen or oxygen nucleophiles, (b) vinyl substitution is preferred regardless of the nature of the sulfur nucleophile and base employed, and (c) double substitution with thiols is unusually facile.…”

“…Acid dissociation constants of the thiols were measured to enable the inductive effects of the arylthio groups to be ranked to aid interpretation of the product distribution. Reactions of 1,2-dichlorotetrafluorobutene with N-acetyl L-cysteine isopropyl ester, which protects rodents against fluoroalkene toxicity [20], were also investigated.…”

The influence of inorganic materials on the pyrolysis of polytetrafluoroethylene. Part 1: The sulfates and fluorides of Al, Zn, Cu, Ni, Co, Fe and Mn

“…Octafluoroisobutene is highly toxic, mainly causing pulmonary oedema, but can also affect the heart muscle [33]. Octafluoro-1-butene and octafluoro-2-butene are not toxic, but are undesirable byproducts as have very limited application in fire fighting [34].…”

Titanium‐Catalyzed C–F Activation of Fluoroalkenes

“…[15] This type of reaction may also provide a promising means of detoxifying highly toxic perfluoroalkenes like perfluoroisobutene and perfluorocyclobutene. [16] Further studies to elucidate the underlying mechanism as well as to expand the scope of the titanium-catalyzed C-F activation are currently in progress.…”