Allylic fluorides trifluoromethyl

Alkyldichlorophosphanes are converted by antimony(III) fluoride into alkyltetrafluoro-A5-phosphanes (RPF4, where R is Me,45,49 Et,45,49 i-Pr,50 allyl,49 Bu45) in 60-80% yield. With electron-withdrawing substituents at the phosphorus atom, e.g. in dichloro(pcntafluoro-phenyl)phosphane, dichloro(chloromethyl)phosphane, dichloro(trichloromethyl)phosphane, diiodo(trifluoromethyl)phosphane or with alkoxy or dialkylamino groups in ROPCl2,... 

Andreev and co-workers have undertaken extensive studies on the reactions of allyl, crotyl, and propargyl alcohols with 2-substituted pentafluoropropenes 14.11 Allyl and crotyl alcohol react at 5-20 C with various 2-substituted pentafluoropropenes 14 in the presence of potassium fluoride in dimethylformamide to give -substituted a-(trifluoromethyl) esters 16. Saponification yields the corresponding acids. 

Methyl perfluoromethacrylate reacts with allyl and propargyl alcohols to give the Michael addition products 19 and 20, respectively these eliminate hydrogen fluoride in the presence of the boron trifluoride-triethylamine complex and rearrange to acyl fluorides 21 and 22. Hydrolysis of the acyl fluorides with base results in decarboxylation to give the 2-(trifluoromethyl) esters 23 and 24.11... 

Bu3Bi mediates the allylation of carbonyl compounds with allyl bromide to give a mixture of homoallyl alcohols and fheir allyl ethers (Scheme 14.133) [278], Tris(4-methoxyphenyl)bismuthane catalyzes the cyanation of carbonyl compounds with MesSiCN [175], In the presence of fluoride ions (CeFsjsBi undergoes nucleophilic substitution with an activated C-F bond of perfluorinated compounds to transfer three CgFj groups [279]. (CFsjsBi can also act as a trifluoromethyl anion equivalent [280]. 

Marrec et al. [34] used trifluoromethyl triflate (TFMT) as a generator of trifluoro-methoxy anion when activated by fluoride anions. Commercially available flnorides (silver fluoride and n-tetrabutylammonium triphenyldifluorosihcate), combined with TFMT, allow a simple generation, in situ, of silver and n-tetrabntylammoninm trifluoromethoxides which were able to react with electrophihc snbstrates. Silver trifluoromethoxide, which is usually more efficient than n-tetrabntylammoninm trifluoromethoxide, converts, under mild conditions, primary ahphatic bromides and iodides as well as primary and secondary benzylic or allylic bromides. Several trifluoromethyl ethers, which could be valuable building-blocks, were prepared in such a way (Scheme 7). 

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