Antimony pentafluonde

Strong acids or superacid systems generate stable fluorinated carbocations [40, 42] Treatment of tetrafluorobenzbarrelene with arenesulfonyl chlorides in nitro-methane-lithium perchlorate yields a crystalline salt with a rearranged benzo barrelene skeleton [43] Ionization of polycyclic adducts of difluorocarbene and derivatives of bornadiene with antimony pentafluonde in fluorosulfonyl chloride yields stable cations [44, 45]... 

Although antimony pentafluonde can fluorinate l,l,2-tnchloro-l,2,2-trifluo-roethane to chloropentafluoroethane, this route is not used industnally because antimony pentafluonde and hydrogen fluoride are too corrosive. Both dichloro-tetrafluoroethane and chloropentafluoroethane are produced by vapor-phase fluor-ination of tetrachloroethene with proprietary chromia catalysts at 300 to 500 °C (equation 1). 

The stabilized fluorinated allylic cation, generated from cis- or trails-1 -(p-methoxyphenyl)pentafluoropropene and antimony pentafluonde in sulfur dioxide, is solvolyzed by methanol to methyl 2-(p-methoxyphenyl)difluoroacrylate [36] (equation 37)... 

The reactions of some fluonnated ethers may result in the elimination of alkyl fluorides In the case of 2-methoxyperfluoro-2-butene, treatment with antimony pentafluonde gives perfluoro-3-buten-2-one and methylfluoride [7071 By reacting 2-chloro-l,l,2-trifluorodiethyl ether with boron trifluonde etherate or with aluminum chloride, chlorofluoroacetyl fluonde can be obtained with the elimination of ethyl fluonde [108] (equations 76 and 77)... 

Isomerization offluoroolefins by a shift of a double bond is catalyzed by halide 10ns [7] The presence of crown ether makes this reaction more efficient [14] Prolonged reaction time favors the rearranged product with an internal double bond (equations 3-5) Isomerization of perfluoro-l-pentene with cesium fluoride yields perfluoro-2-pentenes in a ZE ratio of 1 6 [75] Antimony pentafluonde also causes isomerization of olefins leading to more substituted products [16]... 

Benzidine rearrangement of fluonnated hydrazobenzenes proceeds with a high yield m the presence of a strong acid [57] (equation 12) Ring contraction occurs when 2-bromoheptafluoronaphthalene is treated with antimony pentafluonde [52] (equation 13)... 

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