Perfluoroalkyl nitriles

Recently, it was also found that the perfluoroalkyl nitriles react with quadricyclane at elevated temperature to give the corresponding cyclic adducts 75 (Scheme 2.36). ° Cyclic azadienes 75 containing electrophilic C=N double bond rapidly react with CF3Si(CH3)3 in the presence of CsF catalyst forming stable silanes 76 (Scheme 2.36). Less electrophilic C=C bond remains unchanged in this process. It should be pointed... 

Fluorinated heterodienophiles and heterodienes Diels-Alder reactions in which the dienophiles have perfluoroalkyl-substituted multiple bonds between carbon and a heteroatom are quite common Reported earlier were reactions of perfluoroketones, thiones, ketimines, thioesters, nitroso compounds, and nitriles [9] Examples of a-fluoroimines [107], co-hydroperfluorothioaldehydes [108], perfluorosulfines [109, IIO], and selenocarbonyidifluoride [III] (equations 89-92) have been reported recently... 

Perfluoroalkyl iodides CF3(CF2)XI are commercially available reactants useful for interesting chemistry, offering various functional products such as CF3(CF2) cC,H4I, CF,(CF,)kC2H4—G, where G represents hydroxyl, amine, thio, thiocyanate, isocyanate, nitrile, carboxy, or CF3(CF2)x CH=CH2, CF,(CF2) CH2CH=CH2. 

Tetrahydrochromenes 107, containing perfluoroalkyl and phosphonic groups in the same molecule, have been obtained via the interaction of dimedone 103b with nitriles 108 at room temperature in chloroform (04JFC1853) (Scheme 36). 

Cyclizations with perfluoroacylating agents seem to be quite general for the synthesis of 5(2i7)-oxazolones with aromatic substituents directly bonded to the heterocyclic ring. For example, perfluoroacylation of a solution of an arylgly-cine containing a phosphorus trihalide affords 4-aryl-2-(perfluoroalkyl)-5(2//)-oxazolones (Table 7.1, Fig. 12) Similar results were obtained when amino nitriles were used as starting materials. ... 

Perfluoroalkyl-substituted nitriles react readily with various 1,3 dipoles, such as azomethine ylides [755,156,157],azometlune imines [158],diazoalkanes [759],azides [160 161,162], and nitrile ylides [163] to give stable five-membered ring systems (equation 37)... 

Acyl and perfluoroalkyl diazomethanes react with nitrogen oxides, and a-diazosulfones with nitrosyl chloride or dinitrogen trioxide, to give furoxans. The process is believed to involve nitrosation, followed by loss of nitrogen to form the nitrile oxide which subsequently dimerizes. Nitrosation of dimethylphenacylsulfonium bromide with nitric acid/sodium nitrite gives dibenzoylfuroxan. 

The 1,4-dinucleophilic building blocks used most are 1,2-disubstituted ethanes of the type HXCHiCHjYH, semicarbazides, thiosemicarbazides, hydroxamic acid amides, amidrazones, and 1,2-disubstituted aromatic and heteroaromatic compounds. 1,1-Dielectrophilic building blocks preferentially used are perfluorinated carboxylic acids and their derivatives, such as acid halides, anhydrides, imidoesters, nitriles, perfluoroalkyl chlorosul-... 

Triethylammoniurii enolales of perfluoroalkyl-/f-oxo esters react with nitrile oxides, via the enolic double bond, to give (perlluoroalkyOisoxazolecarboxylates in good yields. Under these conditions, a stepwi.se process is likely involved with initial nucleophilic attack of the cnolate on the US-dipole. ... 

Et3B is an effective tool for halogen atom transfer radical reactions (see also Chap. 1.5). Perfluoroalkyl iodide [29], a-halo nitrile and a-halo ester [30] added to alkenes and alkynes at low temperature. Not only terminal alkenes but also internal alkenes can be employed to furnish iodine atom transfer adducts (Scheme 23). Furthermore, addition of perfluoroalkyl iodide to silyl and germyl enolate provided a-perfluoroalkyl ketones [31]. The reaction would involve the elimination of a tri-... 

Examples of the photoisomerization of pyrazoles to imidazoles have been reported by Nishiwaki et al. In the photoisomerization of perfluoroalkyl-pyridazines to the corresponding pyrazines, Chambers et al. have shown that an intermediate diaza Dewar-benzene is involved rather than a diazaprismane. Ogata and Takagi have observed a novel photoisomerization of 2-pyridylaceto-nitrile to u-aminobenzonitrile, possibly via a Dewar-intermediate. 

Perfluoroalkylsubstituted isoxazoles were prepared in satisfactory yields from nitrile oxides and ethyl 3-perfluoroalkyl-3-pyrrolidino acrylates <01T5781>. 

For the gasket, instead of PP, poly(phenylene sulfide), poly(ethyl-ene terephthalate), poly(amide), liquid crystal polymer, tetrafluoroethyl-ene/perfluoroalkyl vinyl ether copolymer resin, PEEK, and poly(ether nitrile) have been found to be free of explosions and other drawbacks at the reflow temperature." ... 

Mercury photosensitization in the presence of NH3 leads to partial defluorination and functionalization of a variety of perfluoroalkanes to give perfluoroalkyl imines, amines, and nitriles (Scheme 40). Polytetrafluoroethylene can be surface functionalized by this method to give a hydrophilic surface. DFT studies suggest that the [Hg (NH3)2l excited state complex may be involved as a key intermediate. 

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