Dichlorodifluoroethylene

An interesting example is 1,1-dichlorodifluoroethylene which has been studied mainly for its monoadducts. But it can be imagined, because of steric hindrance of CC12-CC12 chaining, that propagation may occur from tail to head addition, thus producing much interest. 

Trifluoromethyl hypofluorite, known for achieving higher yields than those obtained from the corresponding hypochlorites, also behaves differently with respect to various fluoroalkenes. HFP leads to the monoadduct as expected [46], just like VDF [41,42], 1,1-dichlorodifluoroethylene [47],2-perfluorobutene [49] in contrast to the first three adducts or the first ten telomers obtained from 1,2-dichlorodifluoroethylene [48] and CTFE [43-45,48], respectively. 

Iodine monochloride has been studied with various fluoroolefins yielding the monoadduct in all cases, to produce original activated telogens containing CF2I or, better, CFC1I end group [114, 115, 156]. The addition of IC1 to 1,1-dichlorodifluoroethylene was found to be bidirectional but to a lesser extent [ 114] than in the case of that to CTFE [115] and the use of catalyst (e. g. iron) affects the yield and the amount of by-product. HFP requires heat contrary to other monomers [114]. 

How does 1,1-dichlorodifluoroethylene react with 1,3-butadiene What product M is formed ... 

The second problem in the addition of 1,1-dichlorodifluoroethylene to 1,3-butadiene is regiospecificity. Carbon 1 of 1,3-butadiene may become attached either to the carbon holding two chlorines or to the carbon with two fluorines. The cycloaddition of fluorinated alkenes is usually not a concerted four-center reaction in which the bonds are formed simultaneously or nearly so. Instead, the reaction is a stepwise biradical process in which the first step is formation of a free-radical intermediate with a single electron at that end of the double bond that can better accomodate it. That happens at the carbon linked to two chlorine atoms. Thus, a biradical is formed that cyclizes to form 2,2-dichloro-l,l-difluoro-3-vinylcyclobutane M [118, 119, 720]. 

Cycloaddition of 1,1-dichlorodifluoroethylene to 2-phenylisobutenyIidenecyclo-propane (Scheme 26) yields only adduct (120) at 105 °C, but yields 60% of adduct... 

Biradical intermediates are more probable in the cycloaddition of chloro-trifluoroethylene and 1,1-dichlorodifluoroethylene to allene to give the... 

In addition to recent examples of cycloadditions involving per- and poly-fluoro-olefins quoted elsewhere in the present Report, bicyclobutenyl derivatives have been prepared via cycloaddition of 1,1,4,4-tetrafluorobuta-1,3-diene to chlorotrifluoroethylene and 1,1-dichlorodifluoroethylene, e,g ... 

At elevated temperature, 1,2-dichlorodifluoroethylene gave the corresponding sulfenyl chloride in high yield [143,144] ... 

Interestingly, 1,2-dichlorodifluoroethylene has been telomerised with various transfer agents using different initiation processes. Unfortunately fluorotrichloro-methane, in the presence of A1C13 also leads to several by-products [78, 295], whereas several ethers, alcohols or esters are not quite efficient (8-30% monomer conversion, only) [296]. But,perhaloalkyl and trifluoromethyl hypofluorites gave the most encouraging results since telomers were produced [48]. 

What reaction takes place between 1,2-dichlorodifluoroethylene and perfluoropropylene oxide What are the products N and O ... 

The polymerization of unsaturated halohydrocarbons has been studied most extensively in the case of vinyl chloride and closely related compounds. Kainer 1S6) published a book recently on polyvinyl chloride and mixed polymers of vinyl chloride. In addition to chlorovinyl polymers, Schildknecht includes fluorovinyl polymers in his book Hl). Books covering plastics generally include material on the halohydrocarbon polymers (14, 144)- Several papers ISS, IS, 135,143) have been published in the last couple of years dealing with the polymerization of fluorine-containing compounds. Articles on polymerization of chloroprene 14 ), fluoroprene 1S8), chlorotrifluoroethylene 140), tetrafluoroethylene 1S9), vinylidene fluoride (157), and dichlorodifluoroethylene 1S7) have appeared in recent years. 

Potassium salts of a set of heterocycles with different basicities, including imidazole, 2-methylebenzimidazle, 3,5-dimethylpyrazole, 1,2,4-triazole, andbenzo-triazole, were chosen for reactions with tetrafluoroethylene, chlorotiiiluoroethylene, and 1,2-dichlorodifluoroethylene (Fig. 3.102). Reactions with tetrafluoroethylene gave only A-tetrafluoroethyl derivatives, products of addition. (The reaction with the... 

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