Benzyl ammonium fluoride

Benzyl and alkyl tnalkylsilyl ethers undergo clean fluonnation to give good yields of benzyl and alkyl fluorides, respectively, when reacted with a combination of d quaternary ammonium fluoride and methanesulfonyl orp- toluenesulfonyl fluoride. The reactions are applicable strictly to a primary carbon-oxygen bond, secondary and tertiary alkyl silyl ethers remain intact or, under forcing conditions, aie dehydrated to olefins [29] (equation 22)... 

The enantioselective nitroaldol reaction of phe-nylalaninals 45 with nitromethane was also promoted with the N-anthracenylmethyl ammonium fluorides in the presence of potassium fluoride.1411 Interestingly, as shown in Scheme 16, the major product was the (2R,3S)-isomer 46a when N,N-dibenzyl-(S)-phenylalaninal and 12 (R=benzyl, X=F) were used while the (2S,3S)-isomer 46b was major when N-tert-butoxycarbonyl derivative 45b and 12 (R=allyl, X=Br) together with potassium fluoride were used. The nitroalcohols 46a and 46b were respectively converted to amprenavir 47a, a HIV protease inhibitor, and its diastereomer 47b. The... 

E-2-bromomethyleneglutaric esters (>70%) have been obtained from the corresponding 2-bromo-2-bromomethylglutarates using a 25% excess tetra-n-butyl-ammonium fluoride in HMPA [24], A similar procedure converts dimethyl 2-bromo-2-bromomethylsuccinate into dimethyl Z-2-bromomethylenefumarate [25], whereas methyl 2,2-bis(bromomethyl)ethanoate yields the 2-bromomethyl-propenoate when reacted with aqueous sodium hydroxide in the presence of benzyl-triethylammonium chloride [26]. No hydrolysis of the ester is evident at 0°C, but becomes apparent at 25 °C. 

The o-quinodimethane (40) may also be generated by fluoride-induced 1/4/elimination of trimethyl(2-[(trimethylsilyl)methyl]-benzyl) ammonium iodide (43). When this elimination is carried out at low temperature, the reaction conditions are ecjually compatible with the presence of 27, and this provides an additional route to 42. ... 

Ammonium fluoride itself is not widely used, however, sporadic reference to it exists.187 Tetramethylammonium fluoride gives very good yields of the fluoro derivative 2 on reaction with l,6-anhydro-3,4-di-0-benzyl-2-0-(trifluoromethanesulfonyl)-/l-D-mannopyranose (1) in... 

Alternatively, the o-benzoquinodimethane may be generated by fluoride-induced 1,4-elimination from trimethyl[2-(trimethylsilylmethyl)benzyl]ammonium iodide (13a). Interception with l-bromo-2-chlorocyclopropene gave the adduct 15a in 38% yield.Tetrahalocy-clopropenes were, however, unreactive. This method of o-quinodimethane generation has also been applied to pyridine derivatives, and provided a short route to l//-cyclopropa[g]quino-linc (16b).The interception was unsuccessful when the approach was applied to cyclo-propaisoquinoline. ... 

Benzyl trimethyl ammonium hydroxide Cetrimonium bromide Dimethyl diallyl ammonium chloride Laurtrimonium bromide Laurtrimonium chloride Methyl tributyl ammonium chloride Tetrabutyl ammonium bromide Tetrabutyl ammonium chloride Tetrabutyl ammonium fluoride Tetra-n-butyl ammonium hydrogen sulfate Tetra-n-butyl ammonium hydroxide Tetrabutyl ammonium iodide Tetrabutylphosphonium acetate, monoacetic acid Tetrabutylphosphonium bromide Tetrabutylphosphonium chloride Tetraethylammonium bromide Tetraethylammonium hydroxide Tetrakis (hydroxymethyl) phosphonium chloride Tetramethylammonium bromide Tetramethylammonium chloride Tetramethylammonium hydroxide Tetramethyl ammonium iodide Tetraphenyl phosphonium bromide Tetrapropyl ammonium bromide Tetrapropyl ammonium iodide Tributylamine Tributyl phosphine Tributyl (tetradecyl) phosphonium chloride Trioctyl (octadecyl) phosphonium iodide catalyst, phase-transfer Tetraethylammonium chloride Tetraoctylphosphonium bromide Tri-n-butyl methyl ammonium chloride Tri methyl phenyl ammonium hydroxide catalyst, phenolics Triethylamine... 

Acetone Acrylonitrile Ammonium fluoride Ammonium sulfide Benzene Benzoic acid Benzyl alcohol Bromobenzene Butyric acid Carbon tetrachloride Carbon disulfide Carbolic acid... 

Trichlorobenzene Skydrol 500 Anthracene Iron Chloride Benzyl Benzoate Catechol Pyrocatechol 1,2,4-Trichlorobenzene Ammonium Bromide Ammonium Hydrosulfide Ammonium Fluoride... 

Anders verlauft die durch Fluorid-Ion (Casiumfluorid) bewirkte Umlagerung von Benzyl-dia]kyl-(trimethylsilyl-methyl)-ammonium-halogeniden. Hauptprodukt ist in diesem Fall das durch Desilylierung und Sommelet-Hauser-Reaktion entstandene 2-(Dialkyl-amino-methyl)-l-methyl-benzol(I) neben zumeist sehr geringen Mengen (wenige Prozent) an dem durch Stevens-Reaktion entstandenen l-Dialkylamino-2-phenyl-ethan(II)1,2. 

In contrast to the nature of TBAF, tetrabutylammoniuin bifluoride converts benzyl bromide to its fluoride in 100% yield and 4-chloronitrobenzene to 4 fluoromtrobenzene in 70% yield 1-Bromodecane is transformed by tetrabutyl-ammonium bifluoride to 1-fluorodecane in 88% yield, and 1-chlorododecane forms 1-fluorododecane in 83% yield In neither case are significant amounts of the elimination products formed [25]... 

A related process involves fluoride-induced desilylation in HMPA at room temperature of benzyldi-methyl(trimethylsilylmethyl)ammonium halides (20) to (21 62-84% yields R = H, 2-Me, 4-Me, 2-C1,4-Cl, 4-OAc X = Cl, Br).9 100 Compunds (20) were prepared by reaction of the corresponding benzyl halide derivatives with (dimethylaminomethyl)trimethylsilane, Me3SiCH2NMe2. The product of Stevens rearrangement (22) formed competitively and predominantly from precursors (20) having strong electron-withdrawing substituents (R = 2-COMe, 2-CN, 4-CN, 2-NO2, and 4-NO2).100... 

Fluoride ion-assisted desilylation has been extensively used to create an ylid from a /V-silyl methyl-quaternary ammonium salt. Its evolution to final produces) is variable and Sommelet-Hauser and Stevens rearrangement products were obtained (often as major products) in a ratio that can be shifted from one structure to another very close one, as in examples 1 and 2 dealing with //-benzyl salts.246,366 Differences in the solvents used are not significant because in the first example, HMPA does not reverse the ratio, yields and selectivity being just a bit lower, /so-toluene was proposed as an intermediate in example 1 it might also be the intermediate in example 2. Thus product partition reflects the relative ability of the C-H or the C-C bonds to be cleaved to produce aromatization with proton or a-amine carbocation migration. 

The acidifying effect of the nitro group is so profound that very mild bases can be used to catalyse the reaction. This enables selective removal of the proton next to the nitro group and helps to avoid side-reactions involving aldol condensations of the carbonyl component, Common examples include amines, quaternary ammonium hydroxides, and fluorides, Even basic alumina is sufficient to catalyse virtually quantitative addition of this benzylic nitroalkane to cyclohexenone at room temperature ... 

Ac, acetyl AIBN, azobis(isobutanonitrile) All, allyl AR, aryl Bn, benzyl f-BOC, ferf-butoxycarbonyl Bu, Butyl Bz, benzoyl CAN, ceric ammonium nitrate Cbz, benzyloxycarbonyl m-CPBA, m-chloroperoxybenzoic acid DAST, diethylaminosulfur trifluoride DBU, l,8-diazabicyclo[5.4.0]undec-7-ene DCC, /V. /V - d i eye I oh e x y I c ar bo -diimide DCM, dichloromethyl DCMME, dichloromethyl methyl ether DDQ, 2,3-dichloro-5,6-dicyano-l,4-benzoquinone DEAD, diethyl azodicarboxylate l-(+)-DET, L-(+)-diethyl tartrate l-DIPT, L-diisopropyl tartrate d-DIPT, D-diisopropyl tartrate DMAP, 4-dimethylaminopyridine DME, 1,2-dimethoxyethane DMF, /V./V-dimethylformamide DMP, 2,2-dimethoxypropane Et, ethyl Im, imidazole KHMDS, potassium hexamethyldisilazane Me, methyl Me2SO, dimethyl sulfoxide MOM, methoxymethyl MOMC1, methoxymethyl chloride Ms, methylsulfonyl MS, molecular sieves NBS, N-bromosuccinimide NIS, /V-iodosuccinimide NMO, /V-methylmorpho-line N-oxide PCC, pyridinium chlorochromate Ph, phenyl PMB, / -methoxvbenzyl PPTs, pyridiniump-toluenesulfonate i-Pr, isopropyl Py, pyridine rt, room temperature TBAF, tetrabutylammonium fluoride TBS, ferf-butyl dimethylsilyl TBDMSC1, f-butylchlorodimethylsilane Tf, trifhioromethylsulfonyl Tf20, trifluoromethylsulfonic anhydride TFA, trifluoroacetic acid THF, tetrahydrofuran TMS, trimethylsilyl TPAP, tetra-n-propylammonium perruthenate / -TsOH. / -toluenesulfonic acid... 

ESTANO (Spanish) (7440-31-5) Finely divided material is combustible and forms explosive mixture with air. Contact with moisture in air forms tin dioxide. Violent reaction with strong acids, strong oxidizers, ammonium perchlorate, ammonium nitrate, bis-o-azido benzoyl peroxide, bromates, bromine, bromine pentafluoride, bromine trifluoride, bromine azide, cadmium, carbon tetrachloride, chlorine, chlorine monofluoride, chlorine nitrate, chlorine pentafluoride, chlorites, copper(II) nitrate, fluorine, hydriodic acid, dimethylarsinic acid, ni-trosyl fluoride, oxygen difluoride, perchlorates, perchloroethylene, potassium dioxide, phosphorus pentoxide, sulfur, sulfur dichloride. Reacts with alkalis, forming flammable hydrogen gas. Incompatible with arsenic compounds, azochloramide, benzene diazonium-4-sulfonate, benzyl chloride, chloric acid, cobalt chloride, copper oxide, 3,3 -dichloro-4,4 -diamin-odiphenylmethane, hexafluorobenzene, hydrazinium nitrate, glicidol, iodine heptafluoride, iodine monochloride, iodine pentafluoride, lead monoxide, mercuric oxide, nitryl fluoride, peroxyformic acid, phosphorus, phosphorus trichloride, tellurium, turpentine, sodium acetylide, sodium peroxide, titanium dioxide. Contact with acetaldehyde may cause polymerization. May form explosive compounds with hexachloroethane, pentachloroethane, picric acid, potassium iodate, potassium peroxide, 2,4,6-trinitrobenzene-1,3,5-triol. 

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