Difluoroethylene carbonate

The solid electrolyte interface formation process can be influenced by the use of electrolyte additives. Cyclic carbonates containing a vinyl group, such as vinylene carbonate, halogenated cyclic carbonates, such as fluoroethylene carbonate, and difluoroethylene carbonate have been used as electrolyte additives. Other additives are sUyl esters such as sultones, and esters of phosphoric and boric acid. 

Difluoroethylene carbonate Vinylene carbonate Figure 2.11 Cyclic carbonates. 

Combes, J. R. Guan, Z. DeSimone, J. M. Homogeneous Free-Radical Polymerizations in Carbon Dioxide. 3. Telomerization of 1,1-Difluoroethylene in Supercritical Carbon Dioxide. Macromolecules 1994, 27, 865-867. 

Vinyldiazomethane, see 3-Diazopropene, 1132a Vinylene carbonate, see l,3-Dioxol-4-en-2-one, 1084 f Vinyl fluoride, see Fluoroethylene, 0744 f Vinylidene chloride, see 1,1-Dichloroethylene, 0691 f Vinylidene fluoride, see 1,1-Difluoroethylene, 0696 Vinyllithium, 0754... 

Ammonium perchlorate, Impurities, 3998 Azidoacetic acid, 0770 f Aziridine, Acids, 0859 Benzoyl azide, 2694 Benzyl chloroformate, 2926 1,2-Bis(difluoroamino)-/V-nitroethylamine, 0799 Bromine trioxide, 0259 2-Butanone oxime, 1649 2-Butyne-l,4-diol, 1523 Butyraldehyde oxime, 1650 Carbon, Unsaturated oils, 0297 Chlorine, Carbon disulfide, 4041 f l-Chloro-2,3-epoxypropane, Contaminants, 1158 Cyanogen chloride, 0322 Diethyl phosphorochloridate, 1675 f 1,1-Difluoroethylene, 0696... 

Reaction of l-Chloro-l,2-difluoroethylene with Butyllithium and Carbon Dioxide... 

When l-chloro-l,2-difluoroethylene is treated consecutively with butyllithium in tetrahydrofuran (THF) and carbon dioxide, two products, F and G, are obtained after esterification with methanol. What are these products ... 

Butyllithium replaces with lithium both the hydrogen in l-chloro-1,2-difluoroethylene and the chlorine in another molecule of the same compound, in a ratio of 1 2. Subsequent treatment of the reaction mixture with carbon dioxide, water, and esterification with methanol gives a mix-... 

Since no trans-cis isomerization of the starting materials was observed, the only reasonable reaction path which leads to both trans and cis isomers of the product of each reaction is an initial attack of (SiF2) on the carbon-carbon double bond, followed by rearrangement. The higher ratio of configuration retention for the reaction of cis-difluoroethylene agrees with the known fact that c s-CHF=CHF is more stable than its trans isomer (12). 

The presence of halogen substituents on an unsaturated carbon atom greatly reduces the reactivity of the carbon-carbon double bond toward addition of a diboron tetrahalide. Schlesinger and his co-workers reported that they observed no indication of adduct formation by B2CI4 with vinyl chloride, vinyl fluoride, 1,1-difluoroethylene, 1,2-dichloroethylene, or tetrafluoroethylene. Insofar as investigated, these haloolefins were equally inert toward B2F4 23). 

Because of the extreme conditions in conventional direct electrofluorination, porous carbon was used in most cases, occasionally promoted with nickel (346-349). The products of such fluorinations are quite interesting for industrial processing ethylene yields vinyl fluoride and polyfluoroethanes, while acetylene forms difluoroethylene (343) acetone and alcohols give perfluorinated compounds on nickel (349). Unfortunately these studies have focused only on screening possible reactions, and thus little fundamental understanding exists for surface reactions and selectivity control. 

Similarly, in 1,2-difluoroethylene, the ds isomer is energetically preferred to the trans isomer by 1-2 kcal mol (Figure 4.18). Among the different explanations of this cis effect [42] differences in the distortion of the central carbon-carbon bond in the two isomers have been discussed [43]. The extent of energetic stabilization by the cis and gauche effects increases with the substituent electronegativity. 

Cycloaddition l,l-Dichloro-2,2-difluoroethylene. Dichloroketene. Dichlorovinylene carbonate. N,N-Diethyl-l-propynylamine. Diphenylcarbodiimide. see Manganese dioxide, oxidation of dihydrobenzenes, see 4-PhenyI-l, 2,4-triazoline-3,5-dione. 

Difluoroethylene (47) is a useful building block for the preparation of 1,1-difluoroolefins. The vinylic fluorine atoms stabilize the difluorovinyl lithium 48 formed by treatment of 47 with sec-BuLi at -115°C. This carbanTon can be quenched with aldehydes (19,29,30) or carbon dioxide (31) to provide 1,1-difluoroolefins (49,50) which are of utility for further transformations (Scheme 137. Similarly, trifluoroethylene (51) has been utilized to prepare 1,2-difluoroolefins, such as 53 (Scheme 16) (32). Difluoroacetylene 52 was implicated as an Intermediate. 

Even less obvious in this particular case is evidence that the less-substituted radical is actually more stabilised, presumably by negative hyperconjugation with the f3 C—F bonds, than the more-substituted radical is by the attached F atoms.997 Furthermore, in the other striking reversal of expectations, the tert-butoxy radical, which is certainly more electrophilic than methyl, adds to 1,1-difluoroethylene 7.45 at the substituted carbon with a selectivity of 80 20,998 whereas the methyl radical is normal in this case. Thus the coefficients in the LUMO are hardly likely to be the explanation, and one suggestion in this particular case is that there is a growing anomeric effect between the oxygen atom and the two fluorine substituents in the transition structure for the formation of the major intermediate 7.46.988... 

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