2.2. The reaction of S-nucleophiles with internal perfluoroolefins The reactions of S-nucleophilic reagents with internal perfluoroolefins are rather sensitive to conditions of process realization, in particular temperatures. So, the reaction between tetrafluoroethylene pentamer and mercaptanes (at Et3N presence) results a mixture of products [78,79].
Thus a kinetically controllable product is obtained at temperatures –65 - -30 oC (18), whereas - thermodynamically controllable product is observed at room temperature (19) ( Table 1).
Table 1. Temperature effect on the correlation products 18 and 19 [78].
The reactions of hexafluoropropylene dimers with benzylmercaptane and thiophenol at the presence of a triethylamine yield a complex mixture of fluorinated vinylic sulfides with fluorine replacement at double bond and deeper transformation under fluoride-ions action take place [39]. First of all, it depends on the quantity of S-nucleophilic reagent used.
Trimers of a hexafluoropropylene react with mercaptanes at presence Et3N, forming derivative with SR substituents at double bond [49, 80].
Dialkyldithiocarbomates are used as S-nucleophilic agents [81].
The examples from following articles illustrate these processes for other dienes: in the reaction between perfluoro-3,4-dimethylhex-2,4-diene and K2S a perfluorotetramethylthiophene was obtained [32], and when perfluoro-1,2,3,5,6,8a-hexahydronaphthalene reacted with ethylmercaptane 4,8-bis-ethylsulfanyldodecafluoro-1,2,3,5,6,8a-hexahydronaphthalene was produced [82].
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