Trifluoromethyl compounds synthesis

Facile synthesis of optically active trifluoromethylated compounds asymmetric Diels-Alder reaction of trifluoromethylated ot, -unsaturated sulfonamide under high-pressure conditions [79]... 

The state of the synthetic art in this area, in 1979, is much more satisfactory. During the past decade, several new synthetic developments have occurred such that we are closer to the point where the limitations upon synthesis of trifluoromethyl compounds are related more to stability problems in isolated cases, and are not nearly so much due to lack of widely applicable synthetic techniques. We find ourselves, for example, in a position in 1979 where the germanium compound, Ge(CF3)4, which in the past decade, was considered by many workers to be of insufficient stability to permit isolation, has been prepared by four independent methods and is known to be stable to over 100°C. Many of these new synthetic techniques have emerged from studies conducted in our laboratory at the University of Texas and previously... 

Starting from Trifluoroacetic Acid Derivatives Trifluoroacetic acid and its derivatives (e.g., esters, anhydride, fluoral, trifluoroethanol) are the major channel of the organic fluorine industry. They are relatively inexpensive and, compared to halons, they do not exhibit major environmental problems. They are the main source for the synthesis of trifluoromethylated compounds. 

These compounds are generally prepared by the same methods used to synthesize trifluoromethylated compounds. A significant number of reactions described in the CF3 series are also applicable in higher series (C2F5, C3F7, C4F9). However, the synthesis of very highly fluorinated or perfluorinated compounds requires a more... 

Ohkuma T, Kitamura M, Noyori R (2000) In Ojima I (ed) Catalytic asymmetric synthesis, 2nd edn. Wiley-VCH, New York, Chap 1 Pareja C, Martin-Zamora E, Fernandez R, Lassaletta JM (1999) Stereoselective synthesis of trifluoromethylated compounds nucleophilic addition of formaldehyde N,N-dialkylhydrazones to trifluoromethyl ketones. J Org Chem 64 8846-8854 Pellissier H (2005) Tetrahedron 61 6479... 

The synthesis of trifluoromethyl compounds from carboxylic acids using sulfur tetrafluoride... 

See general procedure for the synthesis of trifluoromethyl compounds from carboxylic acids with sulfur tetrafluoride vide supra). Examples with reaction conditions are given in Table 8. 

The synthesis of trifluoromethyl compounds from carboxylic acids using sulfur tetrafluoride has already been discussed in Houben-Weyl Vol. 5/3, p88. 

Synthesis of trifluoromethylated compounds 152 has been achieved via ester-enolate [2,3]-Wittig and [3,3]-lreland-Claisen rearrangements. Perfluorocyclo-butane phosphonium ylides, e.g. 153, have been used as a masked fluoride anion source in their reactions with alcohols and carboxylic acids which lead to alkyl-and acyl-fluorides. Ylides 153 are also reported to cleave Si-C and Si-O bonds, cause dimerisation of fluoro-olefins, and also react with acid chlorides or other activated aromatic compounds under halogen exchange. ... 

Hohorst F.A. and D.D. DesMarteau Some reactions of CF3OO derivatives with inorganic nitrogen compounds. Synthesis and vibrational spectrum of trifluoromethyl peroxynitrate,/norg. Chem. 13 (1974) 715-719. 

The selection of results shows the usefulness of simple and readily available trifluoromethylated compounds deriving mainly from trifluoroacetic acid or trifluoropropene as CF3-carrying reagents. Such an approach avoids tedious Cl-F exchange reactions and leads directly to convergent synthesis of more complex trifluoro-methylated molecules. 

Sterically crowded aryl bismuth compounds synthesis and characterization of bis 2,4,6-tris(tri luoromethyl)phenyl bismuth chloride and tris 2,4,6-tris(trifluoromethyl)phenyl bismuth. /. Organomet. Chem. 402 55-66. 

Konno, T. Kitazume, T. Synthesis of trifluoromethylated compounds with four consecutive asymmetric centers via sequential [3,3]-Ireland-Claisen rearrangement and iodolacto-nization. Tetrahedron Asymmetry 1997, 8, 223-230. 

Kondratenko, N.V. Vechirko, E.P. Yagupolskii, L.M. A convenient method for the introduction of trifluoromethyl groups into organic compounds. Synthesis 1980, (11), 932-933. 

Trifluoroacetaldehyde is difficult to prepare from trifluoroethanol. a-Methoxylated and a-acetoxylated 2,2,2-trifluoroethyl sulfides are trifluoroacetaldehyde equivalents, which are useful building blocks for synthesis of various trifluoromethylated compounds. The a-ace-toxy sulfide 10 is easily converted into trifluoroacetaldehyde phenyl-hydrazone (Eq. 44). The a-methoxy sulfide 9 is also readily transformed into biologically interesting a-monofluoroalkanoic acids (Eq. 45). 

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