Trifluoromethyl acetate

The same authors presented an MD study of the molecular dipole moment and a net charge for [C4mim]+ combined with BFJ, [DCA] and the trifluoromethyl-acetate [89], In contrast to a solution of simple ions in a (non)polar solvent, rotational and translational effects were found to play a role. The theoretical framework necessary to compute the conductivity spectrum and its low frequency limit of ILs was newly developed. Merging these computed conductivity spectra with previous simulation results on the dielectric spectra resulted in the spectrum of the generalized dielectric constant [89], It was calculated for the three ILs over six orders of magnitude in frequency ranging from 10 MHz to 50 THz [89],... 

The prorlucts can equilibrate under the reaction conditions so that the individual yields depend on the ratio of tlie starting materials and the reaction time. Moreover, the individual product yields can be varied by the addition of one of the reaction products. Thus, addition of tris(trifluoromethyl)phosphine or iodine increases the yields of the mono- and diiodophosphines. With excess phosphorus at temperatures above 250°, the major products are phosphorus fluorides and hexa-fluoroethane (14). Results obtained under various reaction condi-tions are summarized in Table II. Since the trifluoromethyl iodide is prepared by the reaction of silver trifluoromethyl acetate with iodine, the trifluoromethylphosphines may be prepared directly from silver trifluoromethylacetate, phosphorus, and iodine (15). 

Within a series of non-haloaluminate ionic hquids containing the same cation species, increasing anion mass corresponds to increasing ionic hquid density (Tables 3.2-1 and 3.2-3). GeneraUy, the order of increasing density for ionic hquids composed of a single cation is mesylate tetrafluorborate < trifluoromethyl acetate < triflate < heptafluoropropyl acetate < bis(trifuoromethylsulfonyl)amide. 

The synthesis of biologically important trifluoromethyl-substituted diox-olanes has been accomplished via 1,3-dipolar cycloaddition reaction of an intermolecularly generated carbonyl yhde with an aryl aldehyde. For example, the reaction of methyl diazo(trifluoromethyl)acetate (25) with two equivalents of aryl aldehydes afforded dioxolanes 27,28 [71]. The diastereoselectivity of these reactions depends on the substituent present on the aryl aldehyde (Scheme 8). 

Geranyl acetoacetate (685) is converted into geranylacetone (686). On the other hand, a mixture of E- and Z-isomers of 688 is obtained from neryl acetoacetate (687). The decarboxylation and allylation of the allyl malonate or cyanoacetate 689 affords the o-allylated acetate or nitriie[447]. The trifluoromethyl ketone 691 is prepared from cinnamyl 4.4,4-trifluoroacetoace-tate (690)[448],... 

Reduction. Quinoline may be reduced rather selectively, depending on the reaction conditions. Raney nickel at 70—100°C and 6—7 MPa (60—70 atm) results in a 70% yield of 1,2,3,4-tetrahydroquinoline (32). Temperatures of 210—270°C produce only a slightly lower yield of decahydroquinoline [2051-28-7]. Catalytic reduction with platinum oxide in strongly acidic solution at ambient temperature and moderate pressure also gives a 70% yield of 5,6,7,8-tetrahydroquinoline [10500-57-9] (33). Further reduction of this material with sodium—ethanol produces 90% of /ra/ j -decahydroquinoline [767-92-0] (34). Reductions of the quinoline heterocycHc ring accompanied by alkylation have been reported (35). Yields vary widely sodium borohydride—acetic acid gives 17% of l,2,3,4-tetrahydro-l-(trifluoromethyl)quinoline [57928-03-7] and 79% of 1,2,3,4-tetrahydro-l-isopropylquinoline [21863-25-2]. This latter compound is obtained in the presence of acetone the use of cyanoborohydride reduces the pyridine ring without alkylation. 

In 1959 Carboni and Lindsay first reported the cycloaddition reaction between 1,2,4,5-tetrazines and alkynes or alkenes (59JA4342) and this reaction type has become a useful synthetic approach to pyridazines. In general, the reaction proceeds between 1,2,4,5-tetrazines with strongly electrophilic substituents at positions 3 and 6 (alkoxycarbonyl, carboxamido, trifluoromethyl, aryl, heteroaryl, etc.) and a variety of alkenes and alkynes, enol ethers, ketene acetals, enol esters, enamines (78HC(33)1073) or even with aldehydes and ketones (79JOC629). With alkenes 1,4-dihydropyridazines (172) are first formed, which in most cases are not isolated but are oxidized further to pyridazines (173). These are obtained directly from alkynes which are, however, less reactive in these cycloaddition reactions. In general, the overall reaction which is presented in Scheme 96 is strongly... 

Molybdenum hexafluoride, in the presence of boron trifluonde, reacts with acetic acid and haloacetic acids at 130-160 °C to give respectively, 1,1,1 tri fluoroethane and 1,1 1 trifluorohaloetlianes in 60-89% yields [2d0, 241] Prolonged treatment of pyridine mono and dicarboxylic acids with an excess of molybdenum hexafluoride at elevated temperatures provides the respective mono-and bis(trifluoromethyl)pyridines in good yields [241] (equation 127)... 

Trifluoromethyl-l-phenylethyl tosylate has been used to differentiate as shown in Table 1, the solvolytic power of three fluorinated solvents and to compare these with formic and acetic acids The three fluorinated solvents are trifluoroacetic acid, trifluoroethanol, and 1,1,1,3,3,3-hexafluoroisopropyl alcohol [55]... 

Trifluoromethyl alkyl ketones also undergo directed aldol condensations under thermodynamic conditions in the presence of piperidine and acetic acid [2, d] Under these reaction conditions, the product suffers a facile dehydration to form the unsaturated trifluoromethyl ketones (equations 2 and 3)... 

In similar work, CF3CCI2CO2CH3 yields methyl a-trifluoromethyl-a,(i-un-saturated carboxylates when reacted with a zinc-copper couple, aldehydes, and acetic anhydride [67] (equation 55). This methodology gives (Z)-a-fluoro-a- -un-saturated carboxylates from the reaction of carbonyl compounds with CFCI2CO2CH3 and zinc and acetic anhydride [6 ]. 

Codeposition of silver vapor with perfluoroalkyl iodides at -196 °C provides an alternative route to nonsolvated primary perfluoroalkylsilvers [272] Phosphine complexes of trifluaromethylsilver are formed from the reaction of trimethyl-phosphme, silver acetate, and bis(trifluoromethyl)cadmium glyme [755] The per-fluoroalkylsilver compounds react with halogens [270], carbon dioxide [274], allyl halides [270, 274], mineral acids and water [275], and nitrosyl chloride [276] to give the expected products Oxidation with dioxygen gives ketones [270] or acyl halides [270] Sulfur reacts via insertion of sulfur into the carbon-silver bond [270] (equation 188)... 

Only one procedure in this category emerged from the present survey. Thus treatment of 1,2-benzenediamine (372) with 3,3-bis(trifluoromethyl)-5-oxazolinone (373, R = H) in ethyl acetate containing a trace of acetic acid at room temperature for a short time afforded 2(l//)-quinoxalinone (374, R = H) in 92% yield 3-methyl- (374, R = Me), 3-isopropyl- (374, R = Pr"), 3-phenyl- (374, R = Ph), and 3-benzyl-2(l//)-quinoxalinone (374, R = CH2Ph) were made similarly in 60-80% yield. ... 

Kolbe radicals can also be trapped by oxygen to yield dialkylperoxides, aldehydes, and ketones [97]. Furthermore methyl and trifluoromethyl radicals from acetic acid and trifluoroacetic acid are trapped, although inefficiently, by pyridine (3-20%) [234], benzotrifluoride and benzonitrile[ 235]. 

The investigated cw-stilbene derivatives, 4-methoxy, 4,4 -dimethyl, unsubstituted, and 4,4 -bis(trifluoromethyl)stilbenes, had k2 values spanning 6-7 powers of ten both in methanol and in acetic acid. Products 2, 4, 5 and 6 were formed. Table 8 reports the results of the cis-trans isomerization test in acetic acid (ref. 29). No acid catalyzed or free radical process was found to be responsible for these isomerizations. 

This was also accomplished with BaRu(0)2(OH)3. The same type of conversion, with lower yields (20-30%), has been achieved with the Gif system There are several variations. One consists of pyridine-acetic acid, with H2O2 as oxidizing agent and tris(picolinato)iron(III) as catalyst. Other Gif systems use O2 as oxidizing agent and zinc as a reductant. The selectivity of the Gif systems toward alkyl carbons is CH2 > CH > CH3, which is unusual, and shows that a simple free-radical mechanism (see p. 899) is not involved. ° Another reagent that can oxidize the CH2 of an alkane is methyl(trifluoromethyl)dioxirane, but this produces CH—OH more often than C=0 (see 14-4). ... 

The enantiomeric excess (ee) of the hydrogenated products was determined either by polarimetry, GLC equipped with a chiral column or H-NMR with a chiral shift reagent. Methyl lactate and methyl 3-hydroxybutanoate, obtained from 1 and 2, respectively, were analized polarimetry using a Perkin-Elmer 243B instrument. The reference values of [a]o(neat) were +8.4° for (R)-methyl pyruvate and -22.95° for methyl 3-hydroxybutcinoate. Before GLC analysis, i-butyl 5-hydroxyhexanoate, methyl 5-hydroxyhexanoate, and n-butyl 5-hydroxyhexanoate, obtained from 1, 5, and 6, respectively, were converted to the pentanoyl esters, methyl 3-hydroxybutanoate was converted to the acetyl ester, and methyl 4-methyl-3-hydroxybutanoate obtained from 2 was converted the ester of (+)-a-methyl-a-(trifluoromethyl)phenyl acetic acid (MTPA). 

Mercuric carboxylates, which decarboxylate by a chain mechanism when initiated by peroxides, also decarboxylate under UV irradiation (123,128,129,131-140,142,144-146,153-155). In addition, decarboxylation was observed for mercuric benzoate and mercuric a-naphthoate (123). Side reactions [Eqs. (24), (25), (109)] observed in peroxide initiated reactions also occurred on UV irradiation, and mercurous salt formation [Eq.(24)] was more extensive under the latter conditions. Decarboxylation giving methylmercuric acetate occurred on irradiation of mercuric acetate in aqueous solution and is considered to be of environmental significance (156,157). Stepwise decarboxylation giving (CF3)2Hg occurred on irradiation of solid mercuric trifluoroacetate at -196° C (158), but, at 20° C, trifluoromethyl radicals diffused from the solid and dimerized (158). No other diorganomercurial has been formed by radical decarboxylation, and the reaction is not preparatively competitive with the thermal decarboxylation synthesis of (CF3)2Hg (26,27) (Section III,A). 

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