Trifluoroethylene, reaction

As part of his elegant and comprehensive examination ot the competition between [2+2] and [2+4] reactions of fluorinated ethylenes, Bartlett found that trifluoroethylene s [2+4] reaction with butadiene competed somewhat with its [2+2] cycloaddirion [66] (equation 62). 

Propagation reactions involving the fluoro-olefins, vinyl fluoride (VF)6Q 7 vinylidene fluoride (VF2)69 7""74 and trifluoroethylene (VF3),75 show relatively poor rcgiospccificity. This poor specificity is also seen in additions of small... 

Sodium cyanide, reaction with chioro-trifluoroethylene to form 3-chloro-2,2,3-trifluoropropionic add, 40, 11... 

Addition of S2C12 to trifluoroethylene and TFE proceeds at 130-150 °C giving the corresponding disulfides in high yield. The formation of small amounts (5-10%) of trisulfides is usually observed in all these reactions. Addition to CFCl=CF2 was first found to be regiospecific, but later it was also shown to be sensitive to reaction temperature [136]. 

The fluorine atoms in trifluoroethylene enhance the rate of attack by the nucleophilic methyl radicals, but retard attack by the electrophilic trifluoromethyl radicals. Methyl radicals add preferentially to the most substituted end of trifluoroethylene, in direct contradiction of the resonance stabilization hypothesis. In fact we can see that the reaction of methyl radicals... 

The mechanism for reactions of SiF2 with various fluorine derivatives like trifluoroethylene F2C=CHF is similar, yielding l,l-difluoro-2-(trifluorosilyl)-ethane F2C=CFSiF3, l,2-difhioro-l-(trifluorosilyl)ethylene FHC=CFSiF3, and 1,2,2-trifluoro-1 -(trifluorosilyl)ethylene F2C=CFSiF3. 

Many examples have been reported of the replacement of a halogen by an amine to produce type B3 co-oligomers, e.g., the tetrasubstituted ethylenes (118 X = CH2, O)144 obtained in high yields by heating chloro-trifluoroethylene with piperidine and morpholine (respectively) at 80°. The reaction of 1,3-dimethyl-4-chlorouracil with 0.5 mole of an alkylene-diamine (in the presence of excess triethylamine) yielded the bisuracilyl-... 

The stoichiometric reaction of CFC-113 with metallic zinc to produce chlorotrifluoroethylene is a well-known process. Catalytic approaches to this synthesis are also available. Charcoal (47) as well as supported nickel, iron, cobalt, and chromium operating at elevated temperature (48) give chlorotrifluoroethylene yields in excess of 90%. The selective replacement of the vinylic chlorine by hydrogen while still maintaining the olefinic linkage provides still another entry into trifluoroethylene. 

The second step in the process given by Eq. (16) is catalyzed by chromium-based catalysts. The effect of oxyfluorides of chromium to carry out the addition reaction of HF to trifluoroethylene at mild temperatures has been described by Von Halasz (49). 

The reactions of S( D) atoms with the fluorinated ethylenes have also been investigated including vinyl fluoride, jem-difluoroethylene, cis-1,2-difluoroethylene, trifluoroethylene, and perfluoroethylene. 

Treatment of vicinal halogen compounds with sodium amalgam results in many cases in a reduction-elimination reaction 4,5-dibromovaleric acid thus forms 4-pentenoic acid on treatment with Na(Hg) [58]. l,l,2-Trichloro-l,2,2-trifluoroethane and 1,2-dichloro-l,l,2,2-tetrafluoroethane react with Na(Hg) similarly, with formation of 1-chloro-l,2,2-trifluoroethylene and tetrafluoroethylene, respectively [62,63]. 

The reaction of trifluoroethylene with tricarbonyltetramethyl-cyclobutadieneiron resulted in the unusual insertion product [65], with... 

Chlorotrifluoroethylene monomer serves as a building block for the CTFE telomer oils as well as the solid higher polymer and various copolymers. CFC-113 also may be used in the production of trifluoroethylene monomer by vapor-phase reduction using hydrogen and a precious metal catalyst, usually palladium [reaction (9)]. Copolymers of trifluoroethylene and vinylidene fluoride show interesting piezoelectric properties. 

---