Trifluoromethylations trifluoromethyl tris copper

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]... 

A second reaction which is very often used for the preparation of phthalonitriles, although the yields are usually not reproducible, is the Rosenmund-von Braun reaction (see Houben-Weyl, Vol. E5, p 1460).106 107 Herein, a benzene derivative with a 1,2-dibromidc or 1,2-dich-loride unit is treated with copper(I) cyanide in dimethylformamidc or pyridine. During this reaction the formation of the respective copper phthalocyanine often occurs. This can be used as an easy procedure for the exclusive synthesis of copper phthalocyanines (see Section 2.1.1.7.),1 os-109 but can also lead to problems if the phthalonitrile is required as the product. For example, if l,2-dibromo-4-trifluoromethyl-benzene is subjected to a Rosenmund-von Braun reaction no 4-trifluoromethylphthalonitrile but only copper tetra(tri-fluoromethyljphthalocyanine is isolated.110... 

Attempts were made not only to find an alternative way to replace dimer and to deposit high-quality poly(tetrafluoro-p-xylylene) film, but also to eliminate the dibromide as the precursor because of the difficulty of synthesis. Therefore, the deposition of poly(tetrafluoro-p-xylylene) film by using hexafluoro-p-xylene as the precursor instead of dibromotetrafluoro-p-xylene was tried. However, no polymer film was deposited on the wafer. Effort was expanded and other metal reagents such as nickel or copper were used to react with l,4-bis(trifluoromethyl)-benzene to generate a,a,a, a -tetrafluoro-p-xylylene to deposit poly(tetrafluoro-p-xylylene) film. However, the result showed that no film was deposited, which was not unexpected, because a C—X bond that is weaker than C—F bonding might be necessary to initiate the formation of the desired intermediate. 

It was shown by us that the reaction of P with CF3I is not limited to the condensed or liquid phase. Red phosphorus is also alkylated by trifluoro-iodomethane vapor over a copper catalyst The products are the same as in the liquid reaction but in reduced yield and different composition. The mono-and dialkylated compounds are the major products wliich is the reverse of the liquid system where the tris (trifluoromethyl)phosphine is usually the dominant product. This indicates that the phosphorus dihalide is a primary product of the reaction and not a decomposition or disproportionation product. 

Recently reported by Cottet and Schlosser regioselective synthesis of tri-fluoromethyl pyridines and -quinolines" " " is based on the trifluoromethylation of iodoheteroarynes using CF3Si(CH3)3/KF/CuI system originally applied by Urata and Fuchikami for trifiuromethylation of aryl halides." Trifluoromethyl copper in this... 

By using a tris(pyrazolyl)borate decorated with nine trifluoromethyl groups as ethylene silver and copper adducts have been prepared... 

Jayaratna NB, Gems II, Mironets RV, Mykhaihuk PK, Yousufiiddin M, Rasika Dias HV. Silver(I) and copper(I) adducts of tris(pyrazolyl)borate decorated with nine trifluoromethyl groups. Inorg Chem. 2013 52 1691-1693. 

Zhang C-P, Wang Z-L, Chen Q-Y, Zhang C-T, Gu Y-C, Xiao J-C (2011) Copper-mediated tri-fluoromethylation of heteroaromatic compoimds by trifluoromethyl siiUbnium salts. Angew Chem Int Ed 50 1896-1900... 

Trifluoromethylpyridine (259) and 2-pentafluoroethylpyridine (260) were obtained by the reaction of 2-iodopyridine (258) and tri- and pentafluoroethylcoo-per at heating in DMF Trifluoromethylcopper and pentafluoroethylcopper are prepared conveniently via the reaction of the solid complex Zn(CF3)Br2DMF with copper(I) bromide in N,N-dimethylformamide (Scheme 76). The maintenance of trifluoromethyl- and pentafluoroethyl derivatives was determined by F NMR spectroscopy in both the mixtures [157],... 

As well as a fluorine substituent, a trifluoromethyl group have recently attracted much attention as the shortest perfluoroalkyl group. A variety of methodologies for the introduction of a trifluoromethyl group into heteroaromatics have been also developed [102], In 1970, Kobayashi et al. reported the copper-mediated direct tri-fluoromethylation of aryl and heteroaryl halides using trifluoromethyl iodide as a source of a trifluoromethyl group [103]. Thus, l-(trifluoromethyl)isoquinoline was synthesized, albeit in low yield (Scheme 29). 

Kobayashi Y, Yamamoto K, Asai T, Nakano M, Kumadaki I. Studies on organic fluorine compounds. Part 35. Trifluoromethylation of pyrimidine- and purine-nucleosides with tri-fluoromethyl-copper complex. J. Chem. Soc., Perkin Trans. 1 1980 2755-2761. 

Molander had developed methods to trifluoromethylate organotri-fluoroborates utilising copper and NaSOaCFs (Langlois reagent) and TBHP (Scheme 18.30). Sanford has developed a similar copper mediated tri-fluormethylation of boronic acids (Scheme 18.31). ... 

Enantioselective total synthesis of ((47J,5iS)-5-Amino-4-(2,4,5-tri-fluorophenyl) cyclohex- l-enyl)-(3-(trifluoromethyl)-5,6-dihydro-[l, 2,4]tri-azolo[4,3-a]pyrazin-7(877)-yl)methanone ABT-341 (708), a DPP4 (dipeptidyl peptidase IV) inhibitor, has been completed in diphenylprolinol silyl ether (707), in the one-pot, multicomponent, reaction of nitroalkene (704), acetaldehyde (703), vinyl phosphonate (706) and amine (705) (Scheme 178) A novel, catalytic, asymmetric Michael addition of azomethine ylide (710) with p-substituted tetraethyl alkyhdene bisphosphates (709) has been realised in the presence of a chiral copper(I)/TF-Bipham-Phos (712) complex. This system provided enantioenriched unnatural i -amino acid derivatives (711) containing gem-bisphosphonates in high yields with... 

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