Trifluoropyruvate, methyl

C-alkylation of secondary and tertiary aromatic amines by hexafluoroacetone or methyl trifluoropyruvate is performed under mild conditions [172] (equation 147) The reaction of phenylhydrazme with hexafluoroacetone leads selectively to the product of the C-hydroxyalkylation at the ortho position of the aromatic ring The change from the para orientation characteristic for anilines is apparently a consequence of a cyclic transition state arising from the initial N hydroxy alky lation at the primary amino group [173] (equation 148)... 

On reaction of methyl trifluoropyruvate with phosphorus pentachlonde 1,1,2,2 tetrachloro-3,3,3-trifluoro-l-methoxypropane IS obtained [273] Hexafluo-roacetone hydrazone is oxidized to bis(tnfluoromethyl)diazomethane upon tieat-ment with phosphorus pentachlonde [274]... 

Burger2 has shown that alkynes undergo both Lewis acid-catalyzed and thermal carbonyl-yne reactions with 3,3,3-trifluoropyruvates to give allenes. Reaction of 1 (Equation (2)) occurs to give a 1 1 mixture of diastereomeric allenyl carbinols 2. Alternatively, reaction of hexyne 1 and methyl trifluoropyruvate with MgBr2-OEt2 at low temperature afforded 2 as an 8 1 mixture of diastereomers. The thermal reaction does not suffer from allylic alcohol byproducts arising from reaction of the substrate with the Lewis acid.3... 

The acyl imines of methyl trifluoropyruvate react as heterodienes with electron-rich olefins in [4 + 2] cycloadditions, as exemplified by the synthesis of trifluoro-methyl aspartic acid (Figure 5.29). ... 

Methyl trifluoropyruvate alkylates a series of substituted indoles catalysed by the chiral non-racemic 2,2/-bipyridylcopper(II) triflate complex (32) to form methyl 3,3,3- trifluoro-2-hydroxy-2-indole-3-yl propanoates [e.g. (33)] in high enantiomeric excess and good yield.37... 

Pyrimido[4,5-6][l,4]thiazines (262) have been prepared by cyclocondensation of the aminothiols (260) with methyl trifluoropyruvate (261) in benzene (89KGS1492), or with 4-substituted 3-halo-2,4-dioxobutyric acid esters (263) at pH 2-5 in DMF to give 6-carbethoxy-7-acyl derivatives of 5H-pyrimido[4,5-6][l,4]thiazines (264) (Equations (38) and (39)). 

A/ -(Methoxycarbonyl)triphenyl-A -phosphane imidc reacts with methyl trifluoropyruvate to form methyl 3,3.3-trifluoro-2-[(methoxycarbonyl)imino]propanoate (34) in 95% yield. This convenient building block readily undergoes addition of nucleophiles, such as Grignard reagents. without competing side reactions at the ester group to form trifluoromethylated amino acids 35. ... 

Keywords Friedel-Crafts alkylation, methyl trifluoropyruvate... 

To indole (4a, 0.3 mmol) in a test tube was added dropwise methyl trifluoropyruvate (1, 0.3 mmol) at ambient temperature. The reaction was stirred for 1 min. The crude product was purified by flash chromatography on silica gel (eluent ethyl acetate/petroleum ether =1 4) to give a light red solid 5a (96%). 

Equation (15)) <84TL943). Similarly, the trifluoroacetylimine (192) of methyl trifluoropyruvate enters into cycloaddition reactions with alkenes such as 2-methylpropene to give the corresponding... 

HFPO also serves as the starting material for trifluoropyruvic acid derivatives. For example, reaction of HFPO with methanol yields methyl 3,3,3-trifluoro-2-methoxy propionate (XII) that in turn yields methyl trifluoropyruvate (Xni) when treated with antimony pentafluoride. The yields of both these reactions are well over 90% (Eq 13.11). 

Enantioselective Friedel-Crafts alkylation reactions were performed between substituted indoles and methyl trifluoropyruvate, using a chiral nonracemic ( -symmetric 2,2 -bipyridyl copper triflate complex as catalyst. The active copper(II) catalyst was... 

Convenient routes to methyl-2-oxalylimino- and 2-(phosphonoformimido)-3,3,3-trifluoropropanoates (165) have been elaborated, based on the reaction of methyl trifluoropyruvate (166) with ethyl oxamate or diethyl carbomoylphosphonate, respectively, followed by dehydration and then alkylation. ... 

A convenient two-step methodology for the preparation of 4-trifluoromethyl-(2//)-pyridazin-3-ones starting from methyl trifluoropyruvate MeTFP (1015) was developed (Scheme 216) [612], The approach relied on aldol condensation of 1015 with various ketones, followed by reaction of the adducts 1016 with hydrazine. Recently, this methodology was used for the preparation of y-secretase modulators [613],... 

Iigashev RA, Sosnovskikh VY, Kahnovich N, Kazakova O, Roeschenthaler G-V (2009) Methyl 2-methoxytetrafluoropropionate as a synthetic equivalent of methyl trifluoropyruvate... 

Fig. 8.24 ln(OTf)3 catalyzed Friedel-Crafts addition of aromatic ring to methyl trifluoropyruvate. 

Li and Wang et al. made use of 5 mol% In(OTf)3 in the Friedel-Crafts type addition of electron-rich aryl compounds to methyl trifluoropyruvate in water [48] (Figure 8.24). 

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