Eliane Laurent

Trifluoromethylation of aromatic compounds with sodium trifluoromethanesulfinate under oxidative conditions.

Abstract Radical trifluoromethylation occurs without Cu(II) but cations are involved with Cu(II). Electron-rich aromatic compounds are triluforomethylated with sodium trifluoromethanesulfinate and t-butyl hydroperoxide. Monotrifluoromethylation predominates in the presence of catalytic amounts of Cu(II) triflate whereas mono- and bis-trifluoromethylated aromatics are obtained in almost equal quantities in the absence of Cu(II).

“Pseudo-cationic” trifluoromethylation of enol esters with sodium trifluoromethanesulfinate.

Abstract Enol esters are converted into α-trifluoromethylated enol esters and/or ketones with sodium trifluoromethanesulfinate and t-butyl hydroperoxide in the presence of catalytic amounts of Cu(II). Enol esters are converted into corresponding trifluoromethylated ketones and/or enol esters with sodium trifluoromethanesulfinate and t-butyl hydroperoxide in the presence of catalytic amounts of Cu(II).

Oxidative fluorination of sulfides in presence of Et3N.3HF

Abstract The synthesis of fluorocompounds by sulfide electrochemical oxidation using Et 3 N.3HF as fluorinating agent is described. Chemical oxidation (DBH) is less efficient.

Mono et difluoration électrochimiques de groupes benzyliques

Abstract Anodic oxidation of benzylic compounds 1 using CH3CN as a solvent and Et3N,3HF as a fluorinating reagent allowed to introduce a fluorine atom in α position of electron withdrawing group via carbocation 1 + (ECBECN mechanism). Whatever the E group monofluorides 2 are obtained in good yields from paramethoxy derivatives 1 (R=p-OCH3). In this case, by raising the potential of working electrode after the monofluorination step, gem difluorides 3 can be directly prepared from 1. When the substituent of the phenyl ring is different of a methoxy group, a mixture of fluoride 2 and acetamide 4 is generally obtained and the ratio of these two compounds is related to cation stability.

Nouvelle methode de preparation de cetones, ester et nitrile benzyliques α-fluoride OU α,α-difluores

Resume By anodic oxidation in CH 3 CN/Et 3 N, 3HF benzylic ketones, ester and nitrile yield specifically corresponding monofluoro or difluoro compounds. The reaction proceeds through an α-carbonyl or an α-cyano carbocation.

Electrofluoration en position benzylique dans le sulfolane

Abstract The use of sulfolane as a solvent instead of acetonitrile in the electrofluorination of benzylic derivatives 1 , (R=H, Cl) gives greater yields of benzylic fluorides 2 , since the formation of acetamido byproducts 4 is prevented. However, the parallel fluorination of the aromatic nucleus is not avoided under these conditions.

TRIFLUOROMETHYLATION OF ORGANIC DISULFIDES WITH SODIUM TRIFLUOROMETHANESULFINATE UNDER OXIDATIVE CONDITIONS: SYNTHESIS OF TRIFLUOROMETHYL THIOETHERS

Abstract Trifluoromethyl thioethers can be obtained from disulfides, sodium trifluoromethanesulfinate and an oxidizer like t-BuOOH, CAN or K2S2O8. The reaction seems to be a radical one and one half of the disulfide molecule only is used for trifluoromethylation. Yields are related to the nucleophilicity of the sulfur atoms. The choice of the solvent can be crucial, especially with aromatic disulfides for which sulfur trifluoromethylation competes with nucleus one.

Improved synthesis of trifluoromethyl sulfones used as intermediates for the preparation of di- or tri-substituted olefins

Abstract Primary and secondary trifluoromethyl sulfones (triflones) are efficiently obtained from easily available sodium trifluoromethanesulfinate (triflinate) and alkyl bromides in N,N-dimethylacetamide. This technique is more powerful than the potassium triflinate/acetonitrile system. Ethyl aconitate can be also produced in one step from ethyl bromoacetate and diisopropylethylamine, sodium triflinate being a catalyst.

Synthesis, enzymatic resolution and absolute configuration of ethyl trans-3-(trifluoromethyl)pyroglutamate

Abstract Ethyl trans -3-(trifluoromethyl)pyroglutamate 1 is synthesized in excellent yield; racemic 1 is enzymatically resolved with α-chymotrypsin-catalyzed hydrolysis affording both the enantiomerically pure enantiomers. The absolute configuration is established by X-ray analysis of the corresponding trichloroethylester.

Synthesis of both enantiomers of 2-fluoro-1-tetralones

Abstract Optically active 2-fluoro I-tetralones (> 95 % e.e) were prepared in two steps by the anodic difluorination of camphanyl enol ester derivatives and subsequent hydrolysis of the fluorinated products of electrolysis. Their absolute configuration was also established.