Perfluoroalkyl amines

Perfluoroalkyl Amines, Ethers, and Carboxylic Acid Derivatives / 201... 

PERFLUOROALKYL AMINES, ETHERS, AND CARBOXYLIC ACID DERIVATIVES... 

Based on the results described above, the base-catalyzed 1,3-proton shift reaction constitutes a general approach to x-(perfluoroalkyl)amines 17 starting from perfluoroaldehydes and perfluoroalkyl ketones. 

Hydrolysis of Benzylideneamines 15 to a-(PerflUoroalkyl)amine Hydrochlorides 16 General Procedure 14... 

Both reagents react with phenols giving mainly o, p-perfluoroalkylated products150,151 and 14 reacts with amines affording 1H, lff-perfluoroalkylated amines or ammonium salts152 (equations 136-139). 

Perfluoroalkyl amines. Thionation of perfluoroacylamines followed by reaction with NBS-BU4NH2F3 constitutes a convenient method for the preparation. 

ECF is successfully used on a commercial scale to produce certain perfluoroacyl fluorides, perfluoroalkylsulfonyl fluorides, perfluoroalkyl ethers, and perfluoroalkylamines. The perfluoroacyl fluorides and perfluoroalkylsulfonyl fluorides can be hydrolyzed to form the corresponding acid and acid derivatives. Examples include perfluorooctanoyl fluoride [335-66-0] perfluorooctanoic acid [335-67-1] perfluorooctanesulfonyl fluoride [307-35-7] perfluorooctanesulfonic acid [763-23-1] and tris(perfluoro- -butyl)amine [311-89-7]. 

Fluorocarbons are made commercially also by the electrolysis of hydrocarbons in anhydrous hydrogen fluoride (Simons process) (14). Nickel anodes and nickel or steel cathodes are used. Special porous anodes improve the yields. This method is limited to starting materials that are appreciably soluble in hydrogen fluoride, and is most useflil for manufacturing perfluoroalkyl carboxyflc and sulfonic acids, and tertiary amines. For volatile materials with tittle solubility in hydrofluoric acid, a complementary method that uses porous carbon anodes and HF 2KF electrolyte (Phillips process) is useflil (14). 

Oil Repellent. Fluorochemicals are the only class of material that can provide oil repeUency without altering the porosity of the paper or paperboard. Physical barriers to oil penetration are used primarily for their moisture- or gas-barrier properties, with retarded oil penetration as a secondary benefit. The most common od-repeUent additives are long-chain perfluoroalkyl phosphate salts of ammonia or diethanol amine. Commercial sources include Scotchban (3M), Zonyl (DuPont), and Lodyne (Ciba Specialties). There are also a fluorochemical carboxylate salt, Lodyne (Ciba Specialties), and fluorochemical copolymers, eg, Scotchban (3M). The widest range of oily fluid holdout is provided by the fluorochemical copolymers. 

Acid hydrolysis of (i-perfluoroalkylvinylamines, prepared from secondary amines and perfluoroalkylacetylenes, yields p-aminovinyl perfluoroalkyl ketones as the major products [79] (equation 20)... 

The reaction of aliphatic primary amines with alkyl a-hydrogenoperfluorocar-boxylates leads to the corresponding P-alkyl iminoesters as the major or the sole tautomers, depending on the length of the perfluoroalkyl chain [ 103] (equation 89). 

Perfluoroalkyl- and perfluoroaryltitanium compounds were prepared m situ via reaction of the corresponding Gngnard reagents with chlorotris(diethyl-amido)titanium [28S] Reaction of the titanium compounds with aldehydes resulted in fluoroalkylative amination [288] (equation 192)... 

Perfluoroalkyl)ethane thiols have been used as precursors to fluorinated surfactants and products for hydro- and oligophobic finishing of substrates such as textiles and leather (1). The synthesis of 2-(perfluoroalkyl)ethane thiol and a byproduct bis-(-2-perfluoroalkylethane)-disulfide (5-10%) has been practiced via the reaction of 2-(perfluoroalkyl)ethane iodide with thiourea to form an isothiuronium salt which is cleaved with alkali or high molecular weight amine as shown in Equation 1 for 2-(perfluorohexyl)ethane iodide (1). 

Addition of HSiMeCl2 to cyclopentadiene is catalyzed by (42) at room temperature at low catalyst loading (0.01 mol.%) to give the (S)-allylsilane in moderate ee.125 This enantioselectivity can be enhanced dramatically with incorporation of perfluoroalkyl groups into the amine functionality (Scheme 26).126... 

Nucleophilic Perfluoroalkylation of Nitrones The reaction of a,N-diaryl nitrones with (trifluoromethyl)trimethylsilane (TMSCF3) gives O-trimethylsilyl ethers of a-(trifluoromethyl)-hydroxylamines. This reaction is initiated by potassium ten -butoxide. Removal of the trimethylsilyl group on acid treatment leads to a-(trifluoromethyl)hydroxylamines, whereas catalytic hydrogenation gives a-(trifluoromethyl)amines (Scheme 2.194). 

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. 

Polyethers, alkanolamides, alkyls, alkylethoxylates, amines, benzyls, carbohydrates, esters, perfluoroalkyls Alkyl-, amidoimidazoline- and carboxy-quaternary ammonium salts Betaines, phosphobetaines, sulfobetaines... 

Various classes of cationic surfactants, including quats, esterquats, alkyl ethoxy amines, quaternary perfluoroalkyl ammoniums and gemini surfactants have been analysed extensively with LC—MS and LC—MS—MS techniques, and their spectra have been fully characterised. Different ionisation methods have been applied for the detection of such surfactants, including API techniques (APCI and ESI) in negative and positive modes of operation. In addition, detailed examples regarding MS—MS fragmentation of these compounds have been reported and presented in this chapter. 

The Pd(PPh3)4-catalysed reaction of perfluoroalkyl iodides with tertiary aliphatic amines gives enamines in 40-50% yields, e.g. equation 98309. 

Perfluoroalkylhalogenomercurates, 3 344-346 Perfluoroalkylmercuric iodides, 3 340 Perfluoroalkyl phosphorus acids, 3 382-387 Perfluoroalkyl tertiary amines, 16 26, 27 structural parameters, 16 27 Perfluoroamines preparation of, 3 356 properties of, 3 361-363 Perfluoro-/-butyl(fluorosulfuryl) peroxide, 16 126... 

Perfluoroalkyl isocyanates react with stoichiometric quantities of primary amines at low temperatures to yield perfluoroalkylureas, and with secondary amines to yield perfluoroacyl amidines [91] (Eq. 60). 

Fluorous Solvents. The fluorous phase is an alternative to the aqueous phase.26 Fluorous (perfluorinated) solvents, such as perfluoroalkanes, perfluoroalkyl ethers, and perfluorinated tertiary amines, have been recognized to be extremely stable and nontoxic and have high density, low solvent strength, and extremely low solubility in water and organic materials. 

Soloshonok and co-workers have developed a method for the synthesis of a-(perfluoro-alkyl)amines from perfluoroalkyl carbonyl compounds by a transamination involving an azomethine a/omethine (Schiffbase) isomerization. They call this method a biomimetic, base-catalyzed 1,3-proton shift reaction, and have applied it to perfluoroaldehydes,12-15 perfluoroalkyl ketones,12 18 / -(perfluoroalkyl)-/l-oxo esters,15 16 19 24 and - -( perfluoroalkyl)-a-oxo es-ters2 " -26 to synthesize the corresponding a-(perfluoroalkyl)amincs, / -(perfluoroalkyl )-/i-amino acids, and 3 -(perfluoroalkyl)- x-amino acids. 

A-Benzylimines 14 are readily prepared from perfluoroaldehydes or perfluoroalkyl ketones and benzylamine by refluxing in benzene or toluene in the presence of a catalytic amount of /)-toluenesulfonic acid, and with azeotropic removal of water.14 (Fluoroalkylidene)amines 14a-... 

Attempts to prepare the A -benzylimine of hexafluoroacelone by treatment of the latter with (benzylimino)triphenyl-/. ,-phosphane give. /V-benzylidene-1,1,1,3,3,3-hexafluoropropan-2-amine [(CF,)2CHN = CHPh] in 56% yield, which results from complete isomerization of /V-benzyl-2,2,2-trifluoro-l-(trifluoromethyl)ethanimine [(CF3)2C = NCH,Ph] under the reaction conditions.12 Taking this into account, the reactivity of substituents R at the imine carbon of compounds 14 follows the order perfluoroalkyl > > aryl > > hydrogen > alkyl benzyl.14 11 as described below, alkoxycarbonyl as the R group in structure 14 (x-oxo ester derivatives) activates as effectively as perfluoroalkyl. 

Alkyl halides with (3-hydrogens generally undergo only elimination reactions under the conditions of the vinyl substitution (100 C in the presence of an amine or other base). Exceptions are known only in cases where intramolecular reactions are favorable. Even alkyl halides without (3-hydrogens appear not to participate in the intermolecular alkene substitution since no examples have been reported, with the exception of reactions with benzyl chloride and perfluoroalkyl iodides. 

Aminoenone (87), when heated with phosphoryl chloride, cyclizes to 2-(trif uoro-methyl)quinoline, rather than the expected 4-isomer.126 A series of crossover experiments using different perfluoroalkyl and aniline moieties suggest an amine exchange process. A 1,3-diaminoallyl cation (88), i.e. a vinylogous formidinimn salt, is proposed to act as turntable in the process. 

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