Trifluoromethanesulfonyl group

A synthetic method for the prepararation of cyclobutanones via an intramolecular cyclization of a ketone enolate has been reported.83 Enol triflates having a silyloxy group at the ft-position under the influence of TBAF give a cyclobutanone or a four-membered enol ether through rearrangement of the trifluoromethanesulfonyl group followed by an intramolecular C- or O-alkylation reaction (Scheme 49). 

The N-Trifluoromethanesulfonyl group increases Lewis acidity of (S,S) diazaaluminolidine (85a), which associates with 3-acryloyl-l,3-oxazolidine-2-one conformationally tightly so as to control the preferred one-side access of the diene in the transition state 86 of the reaction of 87 with 88, as shown in Scheme 5.23 [8]. The same catalysts (85a-c) have been employed for asymmetric radical allylation on the quaternary carbon of coumarin derivatives [9]. Highly trifluoromethylated diols (90 and 91) have... 

An increase in the electron deficiency of the sulfonates, by replacement of a mesyl by a trifluoromethanesulfonyl group, induces an increase in the proportion of alkanes versus alcohols in the product mixture. Thus deoxysugars can be obtained in good yield, either by photolysis of the triflate derivatives in aqueous HMPA or reduction by sodium in liquid ammonia. The detosylation reactions of arenesulfonates and arenesul-fonamides do not always require PET processes. When the photolysis is carried out in solvents such as EtjO or MeOH, the alcohol can be recovered in high yields from arenesulfonates while a mixture of amine and ammonium tosylate is usually obtained from tosylamides. A mechanistic study of the reaction indicated that the bond initially cleaved is different in sulfonates and sulfonamides (Scheme 3). ... 

Trifluoromethanesulfonamides have been introduced in many biologically relevant compounds and represent important chemical motifs for the development of new pharmacophores. An illustrative example is given by the synthesis of a family of tri-fluoromethanesulfonamide analogues of Nimesulide that present inhibitory activity against cyclooxygenase-2 and in vivo antiinflammatory properties. Substitution of benzodiazepine derivatives by a trifluoromethanesulfonyl group enhanced their inhibitory activity toward mitochondrial ATP hydrolase. ... 

Other nitrogen nucleophiles can react efficiently with triflyl chloride. Below —30°C, 1,1-dimethylhydrazine was sulfonated to afford the corresponding trifluoromethanesulfonic hydrazide. In the azole series, the side chain of some 1,2,3-triazoles was functionalized with a trifluoromethanesulfonyl group (eq 10). When pentafluoroethanesulfonyl chloride was used in this transformation, a mixture of mono- and di-sulfonylated derivatives was... 

This method is also useful for the synthesis of alkenyl-substituted trifluoro-methyl sulfone derivatives 91 (Scheme 2.55). Halogen-lithium exchange of iodo-methyltrimethylsilane with Bu Li, followed by addition of 0.5 equivalents of triflic anhydride, provides the a-silyl carbanion bearing a trifluoromethanesulfonyl group. Reactions of the a-silyl carbanion with aldehydes give the corresponding... 

An example of cleavage ol the sulfur-oxygen bond in trifluoromethane-sulfonic ester has been reported Tnfluororaethyl triflate reacts with neutral or anionic nucleophiles with elimination of carbonyl difluoride and formation of trifluoromethanesulfonyl fluoride [57] (equation 32) The mechanism of this reaction involves elimination of fluoride ion, which is a chain carrier in the substitution of fluorine for the trifluoromethoxy group... 

The first use of ionic liquids in free radical addition polymerization was as an extension to the doping of polymers with simple electrolytes for the preparation of ion-conducting polymers. Several groups have prepared polymers suitable for doping with ambient-temperature ionic liquids, with the aim of producing polymer electrolytes of high ionic conductance. Many of the prepared polymers are related to the ionic liquids employed for example, poly(l-butyl-4-vinylpyridinium bromide) and poly(l-ethyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide [38 1]. 

The following abbreviations are commonly used for substituent groups in structural formulae Ac (acetyl), Bn or PhCH2 (benzyl), Bz or PhCO (benzoyl), Et (ethyl), Me (methyl), Me3Si (not TMS) (trimethylsilyl), Bu Me2Si (not TBDMS) (rerf-butyldimethylsilyl), Ph (phenyl), Tf (triflyl = trifluoromethanesulfonyl), Ts (tosyl = toluene-p-sulfonyl), Tr (trityl). 

Bi(III) b/.s(trifluoromethanesulfonyl )amide has also been prepared by our group [60]. This compound proved to be extremely moisture sensitive, and it has to be strictly manipulated (and stored) under argon. 

The trifluoromethanesulfonyl (triflyl group) is one of the strongest electron-withdrawing groups and therefore is a versatile functionality for organic synthesis Trifluoromethyl sulfones have been prepared by using an electrophilic tnflyl source such as triflic anhydride or by displacing primary halides with a inflate salt... 

Chiral Lewis acids are known. Indeed, an air stable and storable chiral Lewis acid catalyst has been prepared, a chiral zirconium catalyst combined with molecular sieves powder. Association of a bulky silicon group with the bis(trifluoromethanesulfonyl)imide anion leads to enhancement of the electro-phihc character of R3SiNTf2. The presence of a chiral substituent derived from ( )-myrtenal on the silicon atom led to a chiral silicon Lewis acid. ... 

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