Fluoromethyl

How do the charges on the ring carbons of toluene and (tri fluoromethyl)benzene relate to the regioselectivity of nitration" ... 

The limitations of this reagent are several. It caimot be used to replace a single unactivated halogen atom with the exception of the chloromethyl ether (eq. 5) to form difluoromethyl fluoromethyl ether [461 -63-2]. It also caimot be used to replace a halogen attached to a carbon—carbon double bond. Fluorination of functional group compounds, eg, esters, sulfides, ketones, acids, and aldehydes, produces decomposition products caused by scission of the carbon chains. 

A -1,3,4-Oxadiazoline, fluoromethyl-rearrangement, 6, 437 Oxadiazolines alkylation, 6, 431 irradiation, 6, 437 mass spectra, 6, 380 oxirane synthesis from, 7, 117-118 ring cleavage... 

At 320 °C, cesium tetrafluorocobaltate converts benzotrifluoride to /n-fluo-robenzotrifluoride, 2f/-heptafluorotoluene, octafluorotoluene, pertluoro-l -meth-ylcyclohexene, and perfluoromethylcyclohexane [29] l,3-Bis(trifluoromethyl)-benzene is convened at 420 °C to 4,5,6-trifluoro-l,3-bis(trifluoroethyl)bcnzene, perfluoro-l,3-dimethylbenzene, and perfluoro-l,3-dimethylcyclohexane [29], p-Xylene gives at 350 °C l,4-bis(difluoromethyl)tetrafluorobenzene, 1-di-fluoromethyl-3-trifluoromethyltetrafluorobenzene, perfluoro-1,3-dimethyl-benzene, and perfluoro-1,3-dimethyloyclohexane... 

Both methyltriethylphosphonium fluoride and methyltributylphospho-nium fluoride have been prepared The latter generates benzyl fluoride from benzyl chloride in 80% yield and ethyl fluoroacetate from ethyl bromoacetate in 53% yield Methyltnbutylphosphonium fluoride converts 1-bromododecane to a 50 50 mixture of 1-fluorododecane and 1-dodecene Methyltnbutylphosphonium fluoride also quantitatively forms styrene from 1-bromo-1-phenylethane [26] Methyl-tnbutylphosphonium fluonde is the reagent of choice for the conversion of N,N dimethylchloroacetamide to its fluoride, but it is not able to convert chloro-acetonitnle to fluoroacetomtrile Methyltnbutylphosphonium fluoride changes chloromethyl octyl ether to the crude fluoromethyl ether in 66% yield The stereoselectivity of methyltnbutylphosphonium fluoride is illustrated by the reac tions of the 2-tert-butyl-3-chlorooxiranes [27] (Table 2)... 

Aryl ethers can also represent the dominant product For example, 3,3 -bis(tri fluoromethyl)-5,5 -dinitrodiphenyl ether is obtained in 54% yield from 3,5-dim trobenzotnfluoride and potassium fluoride in A(A-dimethylformamide with catalytic amounts of water at 160 °C after 24 h [110]... 

The synthesis of fluoroalkyl and chloroalkyl fluoromethyl ketones is achieved by oxidation of the corresponding alcohols by sodium dichromate and sulfunc acid in methylene chlonde in the presence of a phase transfer catalyst [49] (equation 45)... 

Fluoromethyl sulfides are converted to fluoromethanesulfonyl chlorides by reaction with chlorine in waters at low temperatures, intermediate sulfoxides can be isolated [109] (equation 100)... 

The preparation of a tnflate salt may include the decomposition of tnflyl azide by azide ion Tnflyl azide can be prepared by the reaction of the azide ion with tnfluoromethanesulfonyl fluonde or tnfluoromethanesulfomc anhydnde [18] (equauonlS) Anotherone stepprocedureusesaquatemaryammoniumcountenon [J9] (equation 15) This tnflate can react with primary halides to form tn fluoromethyl sulfones [19 (equation 16) (Table 7)... 

Convenient syntheses of vinyl fluorides are of synthetic interest, fhe conjugate base of fluoromethyl phenyl sulfone reacts with carbonyl compounds to provide P-tluoro alcohols, which are used to prepare terminal vinyl fluorides [25] (equation 23) (Table 9) This reaction offers an alternative to the Winig reaction, which may be very sensitive to reaction conditions. 

It has also been possible to prepare extremely stable triphenylphosphonium (trifluoromelhanesulfonyl)melhylide from chloromethyl tri fluoromethyl sulfone and triphenylphosphme [6 ] (equation 60)... 

The photochemical or thermal reaction between petfluoroalkyl iodides and mercury-cadmium amalgams has been used for the synthesis of perfluoro-alkylmercury compounds [150] Functionalized analogues have been prepared similarly via this route [151, 152] (equation 117), and the preparation of bis(tri-fluoromethyl)mercury has been described [153]... 

Aryl bromides were also perfluoroethylated under these conditions [205] The key to improved yields was the azeotropic removal of water from the sodium perfluoroalkylcarboxylate [205] Partial success was achieved with sodium hepta-fluorobutyrate [204] Related work with halonaphthalene and anthracenes has been reported [206 207] The main limitation of this sodium perfluoroalkylcarboxylate methodology is the need for 2 to 4 equivalents of the salt to achieve reasonable yields A trifluoromethylcopper solution can be prepared by the reaction of bis(tri-fluoromethyl)mercury with copper powder in /V-methylpyrrolidone (NMP) at 140 °C [208] (equation 138) or by the reaction of N-trifluoromethyl-A-nitro-sotnfluoromethane sulfonamide with activated copper in dipolar aprotic solvents [209] This trifluoromethylcopper solution can be used to trifluoromethylate aro matic [209], benzylic [209], and heterocyclic halides [209]... 

Perfluoro-2-butyne reacts with sulfur in carbon disulfide to give l,2-bis(tn-fluoromethyl)vinylene trithiocarbonateA and a subsequent products [2] (equation 4). 

Alkynes substituted with one or two trifluoromethyl groups are also highly reactive dienophiles [9] Indeed, hexafluoro-2-butyne is used increasingly as a definitive acetylenic dienophile in "difficult Diels-Alder reactions. It was used, for example, to prepare novel inside-outside bicycloalkanes via its reaction with cir,trnns -l,3-undecadiene [74] (equation 67) and to do a tandem Diels-Alder reaction with a l,l-bis(pyrrole)methane [75] (equation 68) Indeed, its reactions with pyrrole derivatives and furan have been used in the syntheses of 3,4-bis(tri-fluoromethyl)pyrrole [76, 77] (equation 69) and ],4-bis(trifluoromethyl)benzene-2,3-oxide [78] (equation 70), respectively. 

Allenes carrying trifluoromethyl groups, such as l,l-dichloro-3,3-bis(tn fluoromethyl)allene, undergo facile, room-temperature Diels-Alder reactions with cyclopentadiene (87%) and furan (95%) [94]... 

Dehydrochlonnation of cnfluoroacetohydroxamyl chlonde yields tnfluoro-acetorutnle oxide that dimenzes depending on the dehydrochlormatmg agents either to bis(trifluoromethyl)-l,l,2,5-dioxadiazine or to 3,4 bis(tn-fluoromethyl)furoxan [7] (equation 8)... 

Table 11. Multinudear Spectral Data for Fluoromethylated Malonates [72]and Fluoromethylated Trimethylsilanes [97]...

Chemical Name 6-Amino-2-(fluoromethyl)-3-(o-tolyl)-4(3H)-quinazollnone... 

A mixture of 2.0 g (0.064 mol) of 2-fluoromethyl-3-(o-tolyl)-6-nitro-4(3H)-qulnazolinone, Oi g of 5% palladium-carbon and 100 ml of acetic acid is shaken for 30 minutes in hydrogen gas. The initial pressure of hydrogen gas is adjusted to 46 lb and the mixture is heated with an infrared lamp during the reaction. After 30 minutes of this reaction, the pressure of hydrogen gas decreases to 6 lb. After the mixture is cooled, the mixture is filtered to remove the catalyst. The filtrate is evaporated to remove acetic acid, and the residue is dissolved in chloroform. The chloroform solution is washed with 5% aqueous sodium hydroxide and water, successively. Then, the solution is dried and evaporated to remove solvent. The oily residue thus obtained is dissolved in 2 ml of chloroform, and the chloroform solution is passed through a column of 200 g of silica gel. The silica gel column is eluted with ethyl acetate-benzene (1 1). Then, the eluate is evaporated to remove solvent. The crude crystal obtained is washed with isopropylether and recrystallized from isopropanol. 0.95 g of 2-fluoromethyl-3-(o-tolyl)-6-amino-4(3H)-quinazolinone Is obtained. Yield 52.5% MP 195°-196°C. 

Recently, Uneyama reported that treatment of (R)-l-tosyl-2-trifTuoromethylazir-idine 76 (Scheme 3.24) with w-BuLi at -100 °C and subsequent trapping of the anion with electrophiles such as chloroformates produced aziridine-2-carboxylates 77 in good to excellent yields [71]. The retention of the configuration of the tri-fluoromethylated quaternary carbon center in the course of the reaction was confirmed by derivatization of the product and by X-ray studies. 

Table 1.7 Values of for the Cross-Reaction between Fluoromethyl and Ethyl Radicals (25 °C) 172174...

Dediazoniation of three o-substituted benzenediazonium salts in pyridinium poly(hydrogen fluoride) yields different products depending on the substituent, as Olah and Welch (1975) have found. The 2-methyl derivative gives 2-fluoro-toluene. With the 2-nitrobenzenediazonium ion the main product is 3-nitrofluoro-benzene, the 2-isomer being formed only in small quantities. Finally, the 2-tri-fluoromethyl derivative yields all three isomeric trifluoromethylfluorobenzenes. 

Aniline, 2-biomo [Benzenamine, 2-bromo-], p-biomination of, 55, 23 Aniline, 3-biomo- [Benzenamine, 3 biomo-], p-biomination of, 55, 23 ANILINE, 4-bromo-/V,A -dimethyl-3-(tn-fluoromethyl)- [Benzenamine, 4-bromo-A,eAr-dimethyl-3-(trifluoro-methyl-], 55, 20... 

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