Tetraethylammonium fluorid

Methyl, ethyl, and benzyl ethers have been prepared in the presence of tetraethylammonium fluoride as a Lewis base (alkyl halide, DME, 20°, 3 h, 60-85% yields). ... 

A variety of media have been used for the Wallach fluorination reaction anhydrous hydrogen fluoride alone or with cosolvents such as methylene chloride, benzene, or tetrahydrofuran and hydrogen fluoride-pyridine alone or with co solvents such as benzene, glyme, or acetic acid [42,43, 46 50] Solutions of cesium fluoride, tetraethylammonium fluoride, or tetrabutylammonium fluoride in strong acids such as methanesulfonic acid or trifiuoroacetic acid with numerous cosolvents have also been studied [48, 49]... 

Fluoride ion is effective in promoting the reduction of aldehydes by organosil-icon hydrides (Eq. 161). The source of fluoride ion is important to the efficiency of reduction. Triethylsilane reduces benzaldehyde to triethylbenzyloxysilane in 36% yield within 10-12 hours in anhydrous acetonitrile solvent at room temperature when tetraethylammonium fluoride (TEAF) is used as the fluoride ion source and in 96% yield when cesium fluoride is used.83 The carbonyl functions of both p-anisaldehyde and cinnamaldehyde are reduced under similar conditions. Potassium bromide or chloride, or tetramethylammonium bromide or chloride are not effective at promoting similar behavior under these reaction conditions.83 Moderate yields of alcohols are obtained by the KF-catalyzed PMHS, (EtO SiH, or Me(EtO)2SiH reduction of aldehydes.80,83,79... 

With certain exceptions, primary fluorination of carbohydrate derivatives is very facile. Fluoride displacement of sulfonyloxy groups by potassium, or cesium, fluoride in 1,2-ethanediol and a variety of other solvents has frequently been used. Tetrabutylammonium (sometimes tetraethylammonium) fluoride in dipolar, aprotic solvents (mainly ace-... 

The products of the electrolysis of trimethylacctic acid in tetraethylammonium fluoride hydrogen fluoride have been compared for platinum and nickel electrodes.44 Electrolysis on platinum leads mainly to the products of nucleophilic attack of the intermediate carbocation 6 which is formed by oxidation of the /crt-butyl radical, adsorbed on the electrode. 

For further reactions including displacement of the sulfonyl group with a labelled fluorine atom, see refs 191-193. The next homolog, tetraethylammonium fluoride has been also used for nucleophilic substitution of sulfonates. 3 /f-(Tosyloxy)-5 a//-androstan-l 7-one (7) on refluxing with tetraethylammonium fluoride in acetone yields 3a-fluoro-5a//-androstan-l 7-one (8) in 78% yield.194... 

The nucleophilic displacement efficacy of tetraethylammonium fluoride has been efficiently exploited in the preparation of 10 from the alcohol 9 via its trifluoromethanesulfonate derivative.195... 

Tetraethylammonium bromide is much less reactive than the chloride, and tetraethylammonium fluoride trihydrate is unreactive which has been attributed to the effect of water in reducing the nucleophilicity of the fluoride ion in nonaqueous solutions.17 The allylie rearrangement of chlorine in cyclobutene 13 has been reported to be catalyzed by triethylamine.63... 

For this reason, electrophilic additions such as addition of hydrogen halides are very difficult, as can be seen in Explanations 13, 14, and 15. But because of the low overall electron density, the double bonds in perfluoroalkenes are easily attacked by nucleophiles such as fluoride ion. If perfluoropropene is treated with dry potassium fluoride in a proton-donor solvent such as formamide, the fluoride anion joins the less negative carbon of the double bond and forms a negatively charged intermediate that readily reacts with the proton of formamide to give 2 H-perfluo-ropropane [5/]. Such a nucleophilic addition takes place with other fluorides such as cesium fluoride, tetraethylammonium fluoride, and sil-... 

Mak TCW (1985) Crystal structure of tetraethylammonium fluoride-water (4/11), 4 (C2H5)4N+F 11H20, a clathrate hydrate containing linear chains of edge-sharing (H20)4F tetrahedra and bridging water molecules. J Inclusion Phenom 3 347-354... 

Moreover, the electrochemical fluoroacetamidation of cycloalkenes was carried out in acetonitrile with tetraethylammonium fluoride/hydrofluoric acid, in order to obtain fluoroac-etamides 16 and 17, although in low yield. cw-Compounds are the major components of the reaction mixture, as determined by H NMR. This result was ascribed to the acetonitrile addition to the /1-fluorocarbocation absorbed on the electrode surface185-186. 

A special one-pot deprotection-transacylation method involves coupling of activated Fmoc amino acids with Aloc-protected amino acid esters.The Aloc-deprotection proceeds with palladium/phenylsilane in the presence of the acylating species. Using Fmoc-Phe-F the synthesis of the sterically demanding dipeptide Fmoc-Phe-(Me)Aib-OMe was accomplished in a yield of 65% A similar one-pot approach to the acylation of the even more difficult hindered and weakly nucleophilic a-trifluoromethyl amino acid esters involves the intermediate A-Teoc protection. Thus treatment of ( )-Teoc-a-(a-CF3)Leu-OMe with Fmoc-Gly-F and a catalytic amount of tetraethylammonium fluoride in acetonitrile at 50 °C for 1-2 weeks gave ( )-Fmoc-Gly-(a-CF3)Leu-OMe (77%... 

Tetraethylammonium fluoride or potassium fluoride can be used the corresponding bromides, chlorides, and iodides are inactive. The OH group is essential vinyltrimethylsilane itself is not cleaved... 

In some cases, the organic can be extracted from the molecular sieve. For pure-silica BEA, Jones et al. [36] were able to extract the tetraethylammonium fluoride that was used as the structure directing agent (SDA). In that case, a small organic was used to prepare a 12 MR material. In some aspects, this situation is... 

Unsymmetrically substituted cyclic sulfates usually give a mixture of regioisomers during nucleophilic ring opening. For example, cyclic sulfate 187 treated with tetrabutylammonium chloride or tetraethylammonium fluoride gave a mixture of a- and /3-substituted products 188 and 189 in 6 1 to 5 1 ratios, respectively [Eq. (39)]. 

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