Trifluoroacetyl pyrolysis

Hexafluoropropylene oxide (HFPO), which decomposes reversibly to di-fluorocarbene and trifluoroacetyl fluonde with a half-life of about 6 h at 165 °C [30], is a versatile reagent. Its pyrolysis with olefins is normally carried out at 180-2(X) °C, and yields are usually good with either electron-nch or electron-poor olefins [31, 32, 33, 34, 35, 36, 37] (Table 2). The high reaction temperatures allow the eyclopropanation of very electron poor double bonds [58] (equation 10) but can result in rearranged products [39, 40, 41] (equations 11-13)... 

Suggestions of untoward hazard inherent in the preparation of nitrosotrifluoro-methane by pyrolysis of trifluoroacetyl nitrite [1] are discounted in the later reference, which gives full details of the equipment and procedure that had been used uneventfully during the previous decade [2],... 

Decaborane dianion, oxidative coupling, 26 73 Decaboron decahalides, 26 13, 48 hydrogenation of chloride, 26 48 pyrolysis of dianions, 26 48 Decabromotriselenate(lI,IV), 35 290 Decadiene complexes with silver, 12 340 Decaholotellurate(IV), structure, 35 249-251 Decarbonylation, thermal, of trifluoroacetyl derivatives, 27 295-300... 

Though much more stable than acetyl nitrite even at 100°C, the vapour of trifluoroacetyl nitrite will explode at 160—200°C unless diluted with inert gas to below about 50 vol% concentration. Higher perfluorohomologues are more stable [1], A detailed examination of the explosion parameters has been made [2]. This and higher polyfluoroacyl nitrites tend to explode above 140°C at ambient pressure, and handling of large quantities should be avoided [3], especially during pyrolysis [4],... 

Pyrolysis of the cyclic sulfite. 5-(penlafiuoroethyl)-l,3,2,4-dioxathiazole 2-oxide (5). however, gives a mixture of isocyanate, pentafluoropropanonitrile and trifluoroacetyl fluoride. 

Pyrolysis of l,2-bis(trifluoroacetyl)hydrazine and l-phenylsulfonyl-2-trifluoroacetylhy-drazine does not give trifluoroacetaldehydc, but its pyrolysis products, carbon monoxide and fluoroform. This shows that the adjacent perfluoroalkyl group can affect the stability of intermediate reaction products in such an adverse way as to render impractical some conventional reactions. 

Trifluoronitrosomethane may be obtained from photolysis of a mixture of trifluoroiodo-methane and nitric oxide [275, 276] or from pyrolysis of trifluoroacetyl nitrite [277, 278] (Figure 8.108). 

The nitroso compound is also obtained by the pyrolysis of trifluoroacetyl nitrite, which is prepared by reaction of trifluoroacetic anhydride and nitrogen trioxide ... 

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