Trifluoromethanesulfonic anhydride

Trifluoromethanesulfonic anhydride, also known as triflic anhydride, is the chemical compound with the formula (CF3SO2)2O. It is the acid anhydride derived from triflic acid. This compound is a strong electrophile, useful for introducing the triflyl group, CF3SO2. Abbreviated Tf2O, triflic anhydride is the acid anhydride of the superacid triflic acid, CF3SO2OH.[2][3]

Trifluoromethanesulfonic anhydride
Skeletal formula of triflic anhydride
Names
Preferred IUPAC name
Trifluoromethanesulfonic anhydride
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.006.016 Edit this at Wikidata
EC Number
  • 206-616-8
UNII
  • InChI=1S/C2F6O5S2/c3-1(4,5)14(9,10)13-15(11,12)2(6,7)8
    Key: WJKHJLXJJJATHN-UHFFFAOYSA-N
  • C(F)(F)(F)S(=O)(=O)OS(=O)(=O)C(F)(F)F
Properties
C2F6O5S2
Molar mass 282.13 g·mol−1
Appearance colourless liquid
Density 1.6770 g/mL
Boiling point 82[1] °C (180 °F; 355 K)
Reacts to form Triflic acid
Hazards
GHS labelling:
GHS03: OxidizingGHS05: CorrosiveGHS07: Exclamation mark
Danger
H272, H302, H314, H335
NFPA 704 (fire diamond)
Safety data sheet (SDS) Fisher MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Preparation and uses

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Triflic anhydride is prepared by dehydration of triflic acid using P4O10.[2]

Triflic anhydride is useful for converting ketones into enol triflates.[4]

In a representative application, is used to convert an imine into a NTf group.[5] It will convert phenols into a triflic ester, which enables cleavage of the C-O bond.[6][7]

Assay

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The typical impurity in triflic anhydride is triflic acid, which is also a colorless liquid. Samples of triflic anhydride can be assayed by 19F NMR spectroscopy: −72.6 ppm[8] vs. −77.3 for TfOH (std CFCl3).

Safety

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It is an aggressive electrophile and readily hydrolyzes to the strong acid triflic acid. It is very harmful to skin and eyes.[9]

See also

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References

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  1. ^ Bloodworth, A.J.; Curtis, Richard J.; Spencer, Michael D.; Tallant, Neil A. (March 1993). "Oxymetallation. Part 24. Preparation of cyclic peroxides by cycloperoxymercuriation of unsaturated hydroperoxides". Tetrahedron. 49 (13): 2729–2750. doi:10.1016/S0040-4020(01)86350-X.
  2. ^ a b Martínez, A. G.; Subramanian, L. R.; Hanack, M. (2016). "Trifluoromethanesulfonic Anhydride". Encyclopedia of Reagents for Organic Synthesis: 1–17. doi:10.1002/047084289X.rt247.pub3. ISBN 9780470842898.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  3. ^ Baraznenok, Ivan L.; Nenajdenko, Valentine G.; Balenkova, Elizabeth S. (May 2000). "Chemical Transformations Induced by Triflic Anhydride". Tetrahedron. 56 (20): 3077–3119. doi:10.1016/S0040-4020(00)00093-4.
  4. ^ Cacchi, Sandro; Morera, Enrico; Ortar, Giorgio (2011). "Discussion Addendum for: Palladium-Catalyzed Reduction of Vinyl Trifluoromethanesulfonates to Alkenes: Cholesta-3,5-diene". Organic Syntheses. 88: 260. doi:10.15227/orgsyn.088.0260.
  5. ^ Baker, T. J.; Tomioka, M.; Goodman, M. (2002). "Preparation and Use of N,N'-Di-BOC-N''-Triflylguanidine". Organic Syntheses. 78: 91. doi:10.15227/orgsyn.078.0091.
  6. ^ McWilliams, J. C.; Fleitz, F. J.; Zheng, N.; Armstrong, III, J. D. "Preparation of n-Butyl 4-Chlorophenyl Sulfide". Organic Syntheses. 79: 43. doi:10.15227/orgsyn.079.0043{{cite journal}}: CS1 maint: multiple names: authors list (link).
  7. ^ Cai, D.; Payack, J. F.; Bender, D. R.; Hughes, D. L.; Verhoeven, T. R.; Reider, P. J. (1999). "(R)-(+)- and (S)-(−)-2,2'-Bis(Diphenylphosphino)-1,1'-Binaphthyl (BINAP)". Organic Syntheses. 76: 6. doi:10.15227/orgsyn.076.0006.
  8. ^ Dell'Amico, Daniela Belli; Boschi, Daniele; Calderazzo, Fausto; Labella, Luca; Marchetti, Fabio (28 February 2002). "Synthesis, and crystal and molecular structures of the triflato and trifluoroacetato complexes of zinc, Zn(O3SCF3)2(DME)2 and [Zn(O2CCF3)2(DME)]n" (PDF). Inorganica Chimica Acta. 330 (1): 149–154. doi:10.1016/S0020-1693(01)00739-3.
  9. ^ "MSDS - 176176". www.sigmaaldrich.com. Retrieved 2020-08-09.