Subscribe to RSS
DOI: 10.1055/s-0032-1318074
Triflic Acid
Publication History
Publication Date:
10 January 2013 (online)
Introduction
Trifluoromethanesulfonic acid (TfOH), more commonly named triflic acid, is one of the strongest Brønsted acids and well known as a ‘super acid’ with a pKa of –13.6. The reagent is a colorless liquid and stable towards heating, oxidation and reduction. It was first synthesized in 1954 by Haszeldine and Kidd by oxidation of bis(trifluoromethylthio)mercury with aqueous hydrogen peroxide.[ 1 ] It is available on an industrial scale and is produced by electrochemical fluorination. Triflic acid is an effective reagent widely used in organic chemistry and especially as catalyst (historically for esterification and salt formation),[ 2 ] even if more than one equivalent is often used.[ 3 ] However, its utilization mainly includes addition to α-carbonylated alkynes,[ 4 ] hydrogenation,[ 5 ] Friedel–Crafts reaction,[ 6 ] polymerization,[ 7 ] cycloaddition,[ 8 ] deprotection,[ 9 ] initiation of cyclisation sequences,[ 10 ] and as a counterion both for iodonium salts[ 11 ] and N-heterocyclic carbenes.[ 12 ]
-
References
- 1 Haszeldine RN, Kidd JM. J. Chem. Soc. 1954; 4228
- 2 Howells RD, Mc Cown JD. Chem. Rev. 1977; 77: 69
- 3a Kang Y.-B, Gade LH. J. Org. Chem. 2012; 77: 1610
- 3b Rokade BV, Prabhu KR. J. Org. Chem. 2012; 77: 5364
- 3c King FD, Caddick S. Tetrahedron 2012; 68: 9350
- 4 Vasilyev AV, Walspurger S, Chassaing S, Pale P, Sommer J. Eur. J. Org. Chem. 2007; 5740
- 5 Wang D.-S, Zhou Y.-G. Tetrahedron Lett. 2010; 51: 3014
- 6 Abid M, Teixeira L, Török B. Org. Lett. 2008; 10: 933
- 7 Mathers RT, LeBlond C, Damodaran K, Kushner DI, Schram VA. Macromolecules 2008; 41: 524
- 8 Xie H, Zhu J, Chen Z, Li S, Wu Y. Synthesis 2011; 2767
- 9 Rombouts F, Franken D, Martinez-Lamenca C, Braeken M, Zavattaro C, Chen J, Trabanco AA. Tetrahedron Lett. 2010; 51: 4815
- 10 Gigant N, Gillaizeau I. Org. Lett. 2012; 14: 4622
- 11a Bielawski M, Olofsson B. Chem. Commun. 2007; 43: 2521
- 11b For a recent example, see: Merritt AE, Olofsson B. Eur. J. Org. Chem. 2011; 3690
- 12 Solovyev A, Geib SJ, Lacôte E, Curran DP. Organometallics 2012; 31: 54
- 13 For a recent review, see: Chassaing S, Specklin S, Weibel J.-M, Pale P. Tetrahedron 2012; 68: 7245
- 14 Nishimura N, Siegmund A, Liu L, Yang K, Bryan MC, Andrews KL, Bo Y, Booker SK, Caenepeel S, Freeman D, Liao H, McCarter J, Mullady EL, Miguel TS, Subramanian R, Tamayo N, Wang L, Whittington DA, Zalameda L, Zhang N, Hughes PE, Norman MH. J. Med. Chem. 2011; 54: 4735
- 15 For a recent review, see: Merritt EA, Olofsson B. Angew. Chem. Int. Ed. 2009; 48: 9052
For recent examples, see: