Triethylamine hydrofluoride

C. Methyl 3,3-dimethyl-4-oxobutanoate (3). A 50-mL flask, connected to a gas bubbler and equipped with a magnetic stirring bar, is charged with 20 mL of dichloromethane (or tetrahydrofuran), 2.16 g (10.0 mmol) of siloxycyclopropane 2 and 3.64 g (30.0 mmol) of triethylamine hydrofluoride (NEt3-HF) prepared in situ (Note 15). This mixture is stirred for 1 hr at room temperature (Note 16) and diluted with 20 mL of water. The aqueous phase is extracted with three 20-mL portions of dichloromethane. The combined organic phases are dried with magnesium sulfate, filtered, and concentrated on a rotary evaporator (bath temperature below 40°C). Crude product 3 is distilled with a Kugelrohr oven (oven temperature 105°C, 10 mm) to provide 1.26 g (87%) of pure 3 as a colorless liquid (Note 17). 

Copper(ll) acetylacetonate Copper, bis(2,4-pentanedionato-0,0 )- (9) (46369-53-3) Methyl diazoacetate Acetic acid, diazo-, methyl ester (8,9) (6832-16-2) Triethylammonium fluoride Triethylamine hydrofluoride (8) Elhanamine, N,N-diethyl-, hydrofluoride (9) (29585-72-6)... 

The alkylating agent can he a primary halide (chlorides react rather slowly) or a primary tosylate or dialkyl sulfate. In one example cyclohexyl bromide was used, but an extended reaction period was required. The paper also includes two mild conditions for the hydrolysis of (4) to the ketone (5). In one method the intermediates (4) are hydrolyzed by addition of 2 TV hydrochloric acid (overnight, 25°) to the reaction medium. In the other, triethylamine hydrofluoride in THF is added to the reaction mixture after addition of water, the organic products are extracted with methylene chloride. This solution is then treated with dilute NaOH. Triethylamine hydrofluoride presumably effects cleavage of... 

The preliminary report of the fluorination at a platinum anode of naphthalene in acetonitrile containing triethylamine hydrofluoride (see Vol. 1, p. 3) has been amplified, and the method has been improved and applied... 

Electrolysis of a solution of potassium bifluoride in acetic add with platimun electrodes yields no fluorinated product/ but similar electrolysis of a solution of naphthalene in acetonitrile containing triethylamine hydrofluoride apparently gives a-fluoronaphthalene (4—5% yield) and other unspecified fluorinated compounds. The medianism shown in Scheme 1 has been proposed to account for the electrodiemical fiuorination of acetic acid-KHFi at a nickel anode. Kolbe electtolysis of heptafluoro-n-butyric acid has been shown to give perfluoro-n-hraume in ca. 20% yield. ... 

Finally, in contrast to the reactions reported above, 49 reacts131 with dimethyl(methyl-thio)sulfonium fluoroborate (DMTSF) and triethylamine tris(hydrofluoride) in dichlorome-thane to give only 5% of the 1,2-addition product 122. The main products, present in 73 27 ratio, are the exo-exo and endo-exo adducts 123 and 124, formed by exclusive exo attack of the electrophile on the double bond, followed by transannular -participation in the intermediate bridged cation and final addition of fluoride to the nortricyclic cation from both the exo or endo side (equation 120). 

The sonification technique does not work when (1) triethylamine trihydrofluonde is eliminated or (2) when triethylamine is used in place of tnethylamine tn hydrofluoride... 

Several groups have employed N-halosuccinimdes for the halofluorination of alkenes. Laurent and co-workers have found that triethylamine tris(hydrofluoride) is a suitable fluoride source for the halofluorination of a number of alkenes (Scheme 70).137 Other examples of halofluorinations include NBS and tetrabutylammonium fluoride as the halogen sources for the formal addition of BrF across funtionalized cyclohexenes138 and the halofluorination of alkenes and alkynes by all three N-halosuccinimides and polymer-supported HF.139... 

The anti addition of the elements of benzeneselenyl fluoride to alkynes can be achieved by the reaction of disubstituted alkynes with A -(phenylselanyl)phthalimide and triethylamine tris-hydrofluoride. ... 

Triethylamine tris(hydrofluoride) in the presence of DBU reacts quantitatively with 13. Contrary to all examples so far presented of 1,3,2-oxathiaphos-pholane ring opening condensations, an attack of fluoride ion on phosphorus is not stereospecific when performed with diastereomerically pure species, the mixture of diastereomeric compounds 68 is always produced [93, 94]. Oxathi-aphospholane derivatives of 3 -amino-3 -deoxythymidine 48 and 50 under treatment with triethylamine tris(hydrofluoride) in the presence of DBU, followed by detritylation with acidic ion-exchange resin, provided 3 -deoxythymi-dine-3 -N-phosphoramidofluoridate (69) and 3 -deoxythymidine-3 -N-phos-phoramidofluoridothioate (70) (Scheme 18), further purified by preparative TLC in ca. 80% yield [75]. 

In order to give the products of nucleophilic substitution by fluoride ion, the corresponding triflates 9 and 10 of the bromohydrins 6 and 7, triflic anhydride was used in the presence of pyridine and 4-dimethylaminopyridine in dichloromethane at — 35°C. A 3 2 ratio of stereoisomeric triflates was obtained no matter which starting bromohydrin was used. Then adding the triethylamine--tris(hydrofluoride) complex to the mixture at — 35 °C gave the corresponding bromofluoro-derivatives 3 and 4. ... 

Alvemhe G, Haufe G, Lawrent A. 1987. Triethylamine tris-hydrofluoride [(C2H5)3 N.3HF] a highly versatile source of fluoride-ion for the halofluorination of alkenes. Synthesis 6 562-564. 

Hydrohalides, Hydrochlorides, Hydrobromides, Hydriodides Diisopropylamine hydrofluoride Dimethylamine -, Dibutylamine -, Trimethylamine -, Triethylamine -, Diethylaniline -, Piperidine -, 2,2,6,6-T etramethy Ipiperi-dine -, Pyridine -, Quinoline hydrochloride... 

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