Triflic anhydride
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Triflic anhydride is the chemical compound with the formula (CF3SO2)2O. This compound is a particularly strong electrophile, useful for introducing the CF3SO2 group. Triflic anhydride is the acid anhydride of the strong acid triflic acid, CF3SO2OH.
It can be assayed by 19F NMR spectroscopy: −72.6 ppm vs. -77.3 for TfOH (std CFCl3).
[edit] Preparation
The compound is prepared by dehydration of triflic acid using phosphorus pentoxide:[1]
- 2CF3SO2OH + P4O10 → [CF3SO2]2O + P4O8(OH)2
[edit] Illustrative uses
In a representative application, is used to convert an imine into a NTf group.[2]
It will convert phenols into a triflic ester, which enables cleavage of the C-O bond.[3][4]
[edit] References
- ^ Stang, P. J.; Dueber, T. E. "Preparation of Vinyl Trifluoromethanesulfonates: 3-Methyl-2-Buten-2-yl Triflate" Organic Syntheses, Collected Volume 6, p.757 (1988) (preparation of triflic anhydride from triflic acid).
- ^ Baker, T. J. Tomioka, M.; Goodman, M. "Preparation and Use of N,N'-Di-BOC-N-Triflylguanidine" Organic Syntheses, Collective Volume 10, page 266
- ^ McWilliams, J. C. Fleitz, F. J.; Zheng, N.; Armstrong, III, J. D. "Preparation of n-Butyl 4-Chlorophenyl Sulfide" Organic Syntheses, Collective Volume 10, page 147.
- ^ Cai, D.; Payack, J. F.; Bender, D. R.; Hughes, D. L.; Verhoeven, T. R.; Reider, P. J.(R)-(+)- and (S)-(−)-2,2'-Bis(Diphenylphosphino)-1,1'-Binaphthyl (BINAP)" Organic Syntheses, Collective Volume 10, page 112
