Fluonnated amines

Heavily fluonnated aminobenzenes, pyridines, and pyrimidines are diazotized in strong-acid media Solid sodium nitrite added directly to the fluonnated amine dissolved in 80% hydrofluonc acid, anhydrous hydrogen fluoride, or (1 1 wt/wt) 98% sulfuric acid in (86 14 wt/wt) acetic and propionic acids affords the electrophilic fluoroarenediazonium ion Addition of an electron rich aromatic to the resultant diazonium solution gives the fluoroareneazo compound [10 II] (equa tions 9 and 10)... 

Electrochemical fluonnation ot N,N dialkylammo-substituted carboxylic acids as their methyl esters produces the analogous perfluonnated tertiary amine carboxylic acid derivatives in 18-30% yields as well as cyclic amine ethers [JOO]... 

Ring-fluonnated aromatics have found wide applications in pharmaceuticals, crop protection chemicals, polymer intermediates, liquid crystals, etc [10] Routes based on aromatic amines represent one of the major synthetic approaches to these compounds The scope and the techniques have been sufficiently described in reviews [//, I2 and monographs [13, 14, fi] Therefore, only reactions and techniques published after 1971 are discussed... 

Acylation of various oxygen functions by use of common and commercially available fluonnated carboxylic acid denvatives such as trifluoroacetic anhydride or the corresponding acyl halides have already been discussed sufficiently in the first edition [10] Therefore only exceptional observations will be described in this section In the past 15 years, many denvatizations of various nonfluonnated oxygen compounds by fluoroacylation were made for analytical purposes. Thus Mosher s acid chlorides for example became ready-to-use reagents for the determination of the enantiomeric purity of alcohols and amines by NMR or gas-liquid chromatographic (GLC) techniques [//] (equation 1)... 

The addition of primary amines to fluoroolefins under anhydrous conditions yields imines The hexafluoropropene dimer, perfluoro-2-methyl-2-pcntcne, and ten butylamine react to yield a mixture of two compounds m a 9 4 ratio [4] (equation 3) rather than just the major keteiiimme-imine, as previously reported [5] It IS claimed that this result is possible by means of isomerization to the terminally unsaturated difluoromethylene isomer prior to nucleophilic attack Secondary amines add to fluoroolefins under anhydrous conditions to give fluonnated ternary amines m good yields If the fluoroolefin is added to the amine without cooling the reaction mixture, or if an excess of the secondary armne is used, there is a tendency toward dehvdrofluonnation of the ternary amine The products... 

The basicities of amines, ethers, and carbonyl compounds are invariably decreased by fluonnation. 2,2,2-Tnfluoroethylamine (p f = 3.3 [61]) and C 5NH2 = -0.36 [62]) are about 10 times less basic than CH3CH2NH2 and CgH5NH2, respectively, and (CF3)2CHNH2 (p j, = 1 22 [71]) is over 10 times less basic than 1-C3H2NH2. The relative gas-phase acidities in Table 15 illustrate the large effect of fluonnation. Perfluoro-rerf-amines (R )3N and ethers R Rf have no basic character m solution [, 74], and CF3COCF3 is not protonated by superacids [72]. 

The word fluorocarbon has been used here in a generic way to indicate completely fluonnated liquids, including ethers and amines, rather than in its stricter meaning of having only carbon and fluorine atoms The definition of the word perfluori-nated is somewhat vague, because it can include compounds that retain double bonds or protons... 

Replacement of hydrogen with halogen can be carried out in the alpha position of fluonnated ethers, amines, aldehydes, or nitriles In 2,2,3,4,4,4 hexafluoro-butyl methyl ether, chlorination occurs predominantly at the methyl, however, bromination occurs mostly at the internal position of the fluorobutyl group 13[Pg.372]

Fluonnated carboxylic anhydrides and acyl halides as common acylating reagents to convert amines to amides and to acylate suitable heterocyclic nitrogen atoms have already been described in the first edition [70] Like in the acylation at oxygen, much synthetic activity was concentrated in the past few years on the denvatization of biomolecules by fluoroacylation reacnons, that is, tnflmroacetylation of amino sugars,... 

---