4-methyl-1,1,1-trifluoro

W-(Methoxycarbonyl)triphenylphosphine imide reacts with methyl trifluoro-pyruvate to form methyl A -methoxycarbonyl 2 immo-3,3,3 trifluoropropionate m 95% yield This convenient building block easily adds nucleophiles such as Gngnard reagents without competing side reactions at the ester group to form trifluoromethylated amino acids [J.S] (equation 31)... 

Ethanoate Methyl Trifluoro- F.IOb,. 451 477 (Educt) E10b2. 329 (Educt)... 

Methyl 3-Benzylumino-2-methyl-trifluoro- EI0b2. 186f. (On -> En-NIIR)... 

Fluoroaliphatic compounds have been found to be non-reactive towards e q, as can be seen from the behaviour of fluoro- and trifluoro-acetate ions (Anbar and Hart, 1965a). The same conclusion may be inferred from the behaviour of trifluoroacetone and methyl trifluoro-acetate (Hart et al., 1967), the reactivity of which has been shown to be fully accounted for by that of the carbonylic functional group. 

Recently, Mello et al. have disclosed a simple and robust protocol for the generation of methyl(trifluoromethyl)-dioxirane from an aqueous solution of 1,1,1-trifluoroacetone hydrate, sodium bicarbonate, and peroxomonosulfate on a preparative scale (typically <2 g the authors suggest multiple iterations for larger scales). The methyl(trifluoro-methyl)dioxirane is removed from the reaction mixture by the evolved gases (O2, CO2) and has been applied to the oxidation of substrates in a second reaction zone (e.g., the epoxidation of cyclohexenone Scheme 33) <2007S47>. 

Yamamoto and Saito reported that the kinetically controlled generation of the more substituted enolate of unsyimnetrical dialkyl ketones can be realized by the combined use of ATPH and LDA [175]. Precomplexation of ATPH with 2-methyl-cyclohexanone (175) at -78 °C in toluene was followed by treatment with LDA in THF, and the mixture was stirred for 1 h. Subsequent treatment with methyl trifluoro-methanesulfonate (MeOTf) furnished 2,2-dimethylcyclohexanone (177) and 2,6-dimethylcyclohexanone (176) in the ratio 32 1 (53 % isolated yield). Use of ter/-butyl-dimethylsilyl triflate (TBSOTf) in place of alkyl triflates in this alkylation system produced siloxybutylated product 178 as a result of THF ring-opening alkylation occurred similarly at the more hindered a-carbon of the unsymmetrical ketone 175 (Sch. 136) [176]. 

Only a few new reports of ring oxidations have appeared. One method uses dimethyldioxirane or methyl(trifluoro-methyl)dioxirane to convert 2,2-dimethyl-l,3-dioxolanes into 2-hydroxyketones under mild conditions (Equation 29) <1996TL115>. Ozonolysis of 1,3-dioxolanes has also been examined, and the primary reaction product of 2-alkyl-1,3-dioxolanes with ozone was identified as the 2-alkyl-l,3-dioxolan-2-ol <2002JA11260, 2004JA16093>. 

Simply changing the solvent in the Pd-based catalytic system from water to a mixture of water and a perfluorocarboxylic acid (some water is necessary for the reaction see Scheme 6) had no significant effect on product composition formic acid was still the principal product from methane. However, the addition of Cu or Cu chloride to the reaction mixture had a dramatic effect. Methanol and its ester now became the preferred products, with virtually no acetic and little formic acid being formed [40 b]. The activation parameters for the overall reaction determined under the condition when the rate was first order in both methane and carbon monoxide were A = 2 X [O sfa = 15.3 kcal mol . Since methyl trifluoro-acetate is both volatile and easily hydrolyzed back to the acid and methanol, it should be possible to design a system where the acid is recycled and methanol is the end product. Lee and co-workers have recently reported on the further characterization of the catalyst in this bimetallic Pd/Cu system [41]. 

Trimethylbismuthine (1.25 g, 4.9 mmol) in acetonitrile (2 ml) was treated with methyl trifluoro-methanesulfonate (0.9 g, 5.5 mmol) under an argon atmosphere. The mixture was stirred for 6 h at room temperature and then evaporated to dryness under a high vacuum to obtain the bismuthonium triflate as a colorless solid (1.5 g), which was purified by reciystallization from acetonitrile-ether [94AG(E)976]. 

The N(l) atom of 3-aryl-l,2,4,5-tetrazines is oxidized regioselectively by methyl(trifluoro-methyl)dioxirane to give the hitherto unknown iV(l)-oxides (96T2377). 

The zwitterionic monocyclic X S/-silicates 3a-5a were synthesized according to Scheme 2 by reaction of [(dimethylammonio)methyl]trifluoro(methyl)silicate (6a) with one molar equivalent of the 0,0 -bis(trimethylsilyl) derivatives of benzohydroximic acid, oxalic acid or glycolic acid (formation of two molar equivalents of MesSiF). Compounds 3b-5b were prepared analogously starting from trifluoro(methyl)[(2,2,6,6-tetramethylpiperidinio)methyl]silicate (6b) (Scheme 2). 

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