Pentafluoroethyl

Azabicyclo[2.2.0]hexa-2,5-diene, pentakis-(pentafluoroethyl)-synthesis, 2, 304 2-Azabicyclop.2.0]hexadiene reactivity, 7, 360 thermal isomerization, 7, 360 2-Azabicyclo[2.2.0]hexa-2,5-diene synthesis, 2, 304 1 -Azabicyclo[3.2.0]hexadiene synthesis, 7, 361 1 - Azabicyclo[2.2.0]hexane reactions, 7, 344 ring strain... 

Ullman type coupling occurs between aryl halides and trifluoromethyl copper species generated by the action of copper iodide on sodium tnfluoroacetate [168, 169] or on methyl fluorosulfonyldifluoroacetate [170] (equation 145) Similarly the pentafluoroethyl group can be introduced from potassium pentafluoropropion-ate [171] (equation 146)... 

Trifluoromethylalion of aryl iodides was carried out by the fluoride ion in duced cross-coupling reaction of aromatic iodides with tnfluoromethyltnalkyl-silanes in the presence ofcopper(I) salts [219 (equation 147) Some pentafluoro- ethyl derivative was also formed This methodology was extended to pentafluoroethyl-and heptafluoropropyltriethylsilanes [2/9]... 

A polyfluorinated P,y-unsaturated ketone is formed m situ from tributylamine and 3,4-bis(tnfluoromethyl)-3-(pentafluoroethyl)-5,5,6,6,6-pentafluoro-2-hex-anone. The enol form of the unsaturated ketone cyclizes via an intermolecular addition-elimination reaction that involves exclusive attack by oxygen rather than by carbon. This reaction demonstrates the hardness of a F-C= site toward... 

In a senes of papers. Tedder and co-workers reported the factors determining the reactivity of perfluormated radicals with various fluoroethylenes Relative Arrhenius parameters for tnfluoromethyl radicals [17] and pentafluoroethyl radicals [/5] were determined, with higher selectivity demonstrated for the higher homologue Selectivity of addition to unsymmetncal olefins was found also to increase with greater radical branching [19]... 

A 9 1 mixture of 2,4-difluoro-4-pentafluoroethyl-3-trifluoromethyl-2//-, and 2,4-difluoro-2-pentafluoroethyl-3-trifluoromethyl-4//-, as well as 2-pentafluoroethyl-3-trifluoromethyl-4-oxo-4//-pyrido[l,2-n]pyrimidine were characterized by H, and NMR (00JFC105). 2-Trifluoromethyl-3-cyano-4-imino- and -4-oxo-4//-pyrido[l, 2-n]pyrimidines were characterized by and F NMR (00MI27). 

The syn addition of pentafluoroethyl hypofluorite (CF3CF2OF), generated in situ by the action of anhydrous, hydrogen-fluoride-free fluorine gas on sodium trifluoroacetate, to 5-acetyl-5//-dibenz[/i,/]azepine (11) has been reported to yield 12.135... 

In order to test the generality of the synthesis, the reaction of (CzFsljHg with Gel was assessed. This reaction required a higher temperature, 135°, before it proceeded measurably. (Pentafluoroethyl)ger-manium triiodide was the only (perfluoroethyl)germanium halide produced, in 54% yield (15). From this reaction, perfluoroethyl iodide was also isolated (in 30% yield). The reactions of GeBr4 with (CF3)2Hg and (C2F5)2Hg were similar in nature (16). 

A rapid, nonphotochemical, transfer of the alkyl group has been observed at 44° C between [MeCo(BAE)H20)] and [Co"(tfen)] in both the forward and reverse directions, and from the ethyl, but not the pentafluoroethyl, analog and it was suggested that the reaction involved electron transfer accompanied by the transfer of the alkyl group (174a). Whatever the best description of the mechanism, it presumably involves direct transfer... 

Likewise, the pentafluoroethyl substituent plays an important role in the extraordinarily potent antiprogestin properties of compound 6-3, as well as in the insecticide candidate 6-4 (Fig. 6.2). 

The fluorine NMR spectra of pentafluoroethyl ethers are rather non-exceptional, with the fluorine signals appearing as singlets (3/FF < 2 Hz)... 

---