Fluoroolefins reaction with

Fluonnated ylides have also been prepared in such a way that fluonne is incorporated at the carhon P to the carbamonic carbon Vanous fluoroalkyl iodides were heated with tnphenylphosphine in the absence of solvent to form the necessary phosphonium salts Direct deprotonation with butyUithium or hthium dusopropy-lamide did not lead to yhde formation, rather, deprotonation was accomparued by loss of fluonde ion Flowever deprotonation with hydrated potassium carbonate in thoxane was successful and resulted in fluoroolefin yields of45-S0% [59] (equation 54) P-Fluorinated ylides may also be prepared by the reaction of an isopropyli-denetnphenylphosphine yhde with a perfluoroalkanoyl anhydnde The intermediate acyl phosphonium salt can undergo further reaction with methylene tnphenylphosphorane and phenyUithium to form a new yhde, which can then be used in a Wittig olefination procedure [60] (equation 55) or can react with a nucleophile [6/j such as an acetyhde to form a fluonnated enyne [62] (equation 56)... 

The addition of nucleophiles to cyclic fluoroolefins has been reviewed by Park et al. [2 ]. The reaction with alcohols proceeds by addition-elimination to yield the cyclic vinylic ether, as illustrated by tlie reaction of l,2-dichloro-3,3-di-fluorocyclopropene Further reaction results in cyclopropane ring opening at the bond opposite the difluoromethylene carbon to give preferentially the methyl and ortho esters of (Z)-3-chloro-2-fluoroacrylic acid and a small amount of dimethyl malonate [29] (equation 8). 

Reactivity of fluoroolefins in reaction with XOS02F decreases going from TFE to PFIB [8]... 

Conjugate electrophilic nitrofluorination of fluoroolefins could be carried out by reaction with a mixture of concentrated nitric acid and anhydrous HF [3] ... 

Introduction of nitro and fluorosulfonoxy groups can be carried out by reaction of ionic 02N0S02F with fluoroolefins [8,116-118]. Nitronium fluorosulfa-te is not as active as halogen fluorosulfates addition to CH2=CF2 and CFH=CF2 proceeds only at ambient temperature [117]. Reaction with TFE and chloro-fluoroethylene proceeds at a noticeable rate at temperature above 50 °C, while addition to 2-H-F-propene only at temperatures higher than 120 °C [117] ... 

Electrophilic activation of sulfur chlorides could be achieved by conducting the reaction with fluoroolefin in the presence of strong acids. For example, trifluoropropene readily reacts with the mixture S2C12/HF/SF4 to produce the corresponding isopropylsulfide 55 in high yield [143] ... 

Reactivity of sulfur chlorides significantly increases when reaction with fluoroolefin is carried out in fluoro- or chlorosulfonic acids, since strong protic acids are able to increase electrophilicity of the molecule by protonation [145]. For example, HFP reacts with solution of SC12 in H0S02F at 40-60°C and atmospheric pressure to give a mixture of products from which the corresponding sulfenyl chloride was isolated in 75% yield ... 

Alkylation of fluoroolefins is probably the most studied reaction of that kind. Different aspects of this process, such as reaction with formaldehyde and hexamethylenetetramine in HF [3], or condensation of halomethanes with fluoroethylenes, catalyzed by AlCl3 [27] have been reviewed. A recent development in this field mostly associated with the introduction of new catalysts, such as SbF5 [7] or aluminum chorofluoride AlClxFy [12], was covered in two other review articles. Here a brief description of some of these reactions is given. 

Partially fluorinated vinyl ethers of fluoroolefins are quite susceptible to the action of Lewis acids. Reaction usually proceeds with ionization of the allylic C-F bond and results in formation of C=0 group and elimination of alkyl halide. Indeed, 3-chloro-2-methoxyhexafluoro-2-butene 82 reacts with A1C13 with formation of trichlorovinyl ketone 83, and cyclic alkoxyfluoroalkenes demonstrate similar behavior in reaction with aluminum or tin(IV) halides [170] ... 

The last 20 years or so have been a period of intensive development in the area of electrophilic reactions of fluoroolefins. Fluorine substituents impart unique reactivity to polyfluorinated olefins, and the knowledge of their behavior in reactions with electrophiles is important for synthetic chemists working in this area. 

The reactions of difluorosilylene with olefins and fluoroolefins [e.g., Eqs. (46) and (47)] appear to proceed by quite different pathways. Similarly, the reaction with benzene resulted in addition products (71, 107) [Eq. (49)], whereas reaction with fluorobenzene led to insertion products (107) [Eq. (50)]. 

Irradiation of Au(CH3)L (L = PPh3 or PPh2Me) in the presence of the fluoroolefins C2F4, C3F6, and C2F3CI has been reported to give insertion products of the type 137 [Eq. (128)] 159). Similar reaction with hexa-... 

Pyridine-l-oxide and some of its ring-substituted derivatives act as nucleophiles and generally give the corresponding 2-(l,2,2,2-tetrafluoro)pyndmes upon reaction with hexajluoropropene [21,22]. The reaction involves a novel rearrangement, as illustrated in the proposed mechanism (equation 10 and Table 1) Initial attack of the fluoroolefin by the oxygen produces an intermediate 1,5 dipole, followed by collapse and extrusion of carbonyl fluoride... 

Chloro- (69, 70) and fluoroolefins (69, 250, 511) also have been observed to form stable complexes upon reaction with tetrakis(triphenyl-phosphine)platinum(O). These show no C=C stretching band in the... 

Excess allyl fluoride is reported to react vigorously with B2CI4 at —80° C to produce a product mixture including BCI3, BFj, B2F4, and allyl chloride (23). The reaction is thus similar to the B2Cl4-fluoroolefin reactions mentioned previously. 

The fluoropyridazines have been intensively investigated by Musgrave and co-workers. Earlier work or nucleophilic substitutions in perfluoro-pyridazines has been reviewed. Tetrafluoropyridazine reacts with hexa-fluoropropene to give products formed from both kinetic and thermodynamic control of the polyfluoroalkylation, i.e., the fluoride ion-induced reaction between a fluoroolefin and an activated polyfluoroaromatic compound. The reaction with tetrafluoroethylene is kinetically controlled. Products arising only from thermodynamic control are formed, however, in the reaction with octafluoroisobutene. 

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