Trifluoromethanesulfonic triflic anhydride

Triflic anhydride (trifluoromethanesulfonic anhydride, > 98%) was purchased from Fluka Chemika and used as received. 

A communication from Baldwin on triflic anhydride (trifluoromethanesulfonic anhydride) describes this reagent as being superior for the conversion of form-amides and vinyl formamides to isocyanides and vinyl isocyanides in yields of about 80% [1237]. Dehydration with triflic anhydride seems to be the method of choice for preparing epoxy isocyanides (see below). 

Trifluoromethanesulfonic (triflic) anhydride is commercially available or can be prepared easily by the reaction of triflic acid with phosphorus pentoxide [66] This moderately hygroscopic colorless liquid is a useful reagent for the preparation of various organic derivatives of triflic acid A large variety of organic ionic triflates can be prepared from triflic anhydride A recent example is the preparation of unusual oxo-bridged dicatiomc salts of different types [SS, 89, 90, 91, 92, 93] (equations 38-44) Stabilized dication ether salts of the Huckel aromatic system and some other systems (equations 38 and 39) can be prepared in one step by the... 

Direct oxidation of bis-sulfides by trifluoromethanesulfonic anhydride was suggested only recently.57 For example, treatment of 10 with triflic anhydride affords the corresponding dication salt 34 in high yield via intermediate formation of a sulfonyl sulfonium salt 33.58 A number of other cyclic and acyclic bis-sulfides 35 undergo facile oxidation to dications under these conditions (Scheme ll).57... 

In 1975, Hendrickson and Schwartzman reported a different mode of phosphorus-based hydroxyl activation using bis(phosphonium) electrophiles (R3P—O—PR3)2+. These highly reactive electrophiles are generated from the reagent combination of phosphine oxide and trifluoromethanesulfonic (triflic) anhydride [96]. Mukaiyama... 

The most common activator for the glycosyl sulfoxides is trifluoromethanesulfonic anhydride (triflic anhydride), which, in the absence of nucleophiles, rapidly and cleanly converts most sulfoxides into the corresponding glycosyl triflates in a matter of minutes at —78 °C in dichloromethane solution [86,280,315,316]. In the more extensively studied mannopyranose series, only the a-mannosyl triflate is observed by low-temperature NMR spectroscopy (Scheme 4.35) [280]. In the glucopyranose series, mixtures of a- and (1-triflates are observed, in which the a-anomer nevertheless predominates (Scheme 4.36) [280],... 

Amides of trifluoromethanesulfonic acid (triflamides) can be prepared by the reaction of the corresponding amines with triflic anhydride The most applicable in organic synthesis are iV-phenyltriflamides, which can be used as mild and selective Inflating reagents [110, lll ... 

Tri-n-butyltin trifluoromethanesulfonate, Bu SnOSO CF, (1). The triflate, m.p. 41-43°, is prepared by reaction of tri-n-butyltin oxide with triflic anhydride (93% yield) or by reaction of Bu- SnH with CFjSOjH. 

Esters of very strong protonic acids (trifluoromethanesulfonic, fluoro-sulfonic, perchloric), however, are sufficiently strong alkylating agents to initiate the polymerization of even weakly nucleophilic monomers (cyclic acetals, ethers) [2-6], Also their anhydrides (e.g., triflic anhydride) are efficient initiators. This last compound is especially interesting, because in the polymerization of cyclic ethers it leads to macromolecules with two identical growing chain ends (difunctional initiator) [30] ... 

Mercury(II) trifluoromethanesulfonate-N,N-Dimethylaniline (1). The reagent is prepared by reaction of triflic anhydride with yellow HgO in nitromethane with stirring for 18 hours. Then the amine is added, and a clear pale yellow solution is formed. 

Dialkylboron trifluoromethanesulfonates, RaBOTf. These triflates are prepared by reaction of trialkylboranes with triflic anhydride. 

Trifluoromethanesulfonic (triflic) anhydride (0.32 mL, 1.90 mmol) and 2,6-di-f-butyM-methylpyridine (0.396 g, 1.93 mmol) were dissolved in 20 mL of anhydrous CH Clj at 25°C, and to this solution was added 0.475 g (1.36 mmol) of l,2,3,4-tetra-C>-acetyl-3-D-giuco-pyranose (3) [40] in 10 mL of CH Cl. After stirring at 25°C for 1 h, the reaction mixture was poured into 200 mL of ice water containing 2 g of NaHCOj and shaken vigorously. The layers were separated, and the aqueous layer was extracted with 20 mL of CHjClj. The combined organic extracts were dried over NajSO, and the solvent was removed by distillation under reduced pressure. Chromatography produced 4 in 84% yield, mp 85 °C dec. 

Disubstituted cyclopropenones 1 were converted into the highly moisture-sensitive trifluoromethanesulfonate salts of the bis(cyclopropenyliumyl) ether dications by the reaction with 0.5 equivalents of triflic anhydride. " ... 

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