Amine hydrofluorides

There are some examples of optically active epoxides in the patent literature which are converted into optically active fluoro alcohols by treatment with amine hydrofluorides of various compositions, but the quoted yields of about 20% arc low compared to those generally obtained. 

Table 17 indicates some limitations of the amine hydrofluorides in the reaction with glycidic esters. In the least-substituted case (entry 1) the yield is low. On the other hand, the fully substituted glycidic esters (entries 8 and 9) do not react at all with the amine hydrofluoride, probably due to steric hindrance. This type of epoxide gives better results with other fluorination reagents, e.g. they can be opened to the fluorohydrins in good yield with hydrogen fluoride in the presence of the boron trifluoride-diethyl ether complex (sec Section 1.1.4.3.2.1.2.).37... 

This may be inferred from the finding that treatment of vinylidene fluoride-chlorotrifluoroethylene copolymers with an amine produces the amine hydrochloride in high yield but very little amine hydrofluoride [3]. Since polychlo-rotrifluoroethylene is unreactive towards amines (RNH2), the following substitution may be discounted ... 

Alkylamine hydrofluorides are commercially available or may be easily prepared by mixing the appropriate amounts of amine and hydrogen fluoride with or without a solvent. The fluo-rinating reactions are usually performed neat at elevated temperatures and ordinary glass equipment can be used in most cases. 

Similar results, with even higher regiosclectivities than wdih diisopropylaminc trishydrofluoride. arc reported for the reaction of simple epoxides with Hiinig s hydrofluoride" (i.e., the 1 1 adduct ofA .A-diisopropylethylamine and hydrogen fluoride, which in turn is prepared ill situ by the addition of the appropriate amount of amine to the amine trishydrofluoride). ... 

Cetyl alcohol propoxylates. See PPG cetyl ether Cetyl amine. See Palmitamine Cetylamine hydrofluoride CAS 3151-59-5 EINECS/ELINCS 221-588-7 Synonyms Hexadecanamine hydrofluoride Hexadecylamine hydrofluoride Hexadecylammonium fluoride Classification Organic salt Empirical CieHseFN Formula CH3(CH2)i5NH2 HF Properties M.w. 261.53... 

The Baltz-Schiemann reaction is still one of the most common methods for direct ring fluorination because of the accessibility to aminated isoquinoline derivatives. The original conditions, which involve the use of tetrafluoroboric acid (fluoroboric acid), are still often employed, [23-27] even though several modified procedures have been reported. For example, Myers synthesized 1-fluoroisoquinoline 2 by the dealkylative diazotization of 1-fcrt-bntyl-aminoisoquinoline 1 with pyridine hydrofluoride instead of HBF4 (Scheme 8) [28]. 

One of the syntheses of 198 is based on pyrazine 200 (Scheme 47) [165, 166]. Compound 200 was transformed to methoxy derivative 201 via diazotization step 201 was then subjected to Buchwald - Hartwig amination to give 202. Ester 202 was transformed to amide 203 diazotization of 203 in the presence of pyridine hydrofluoride led to the formation of fluoro derivative 204. The last step of the synthesis included deprotection of the methyl ether to give 198. 

Chambers R, Korn S, Sandford G (1994) Reactions involving fluoride ion. Part 37. Proton Sponge hydrofluoride as a fluoride ion donor. J Fluor Chem 69 103-108 Chambers R, Gray W, Korn S (1995) Reactions involving fluoride ion. Part 40. Amines as initiators of fluoride ion catalysed reactions. Tetrahedron 51 13167-13176... 

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