Trifluoroacetic anhydride is used for the introduction of trifluoroacetyl group in organic synthesis. It is involved in the preparation of N- and O-trifluoroacetyl derivatives of a wide range of biologically active compounds for gas chromatography analysis. It plays an important role as desiccant for trifluoroacetic acid. It is also used in the oxidation of aldehydes to acids, esters, amides as well as in the protection of alcohols and amines. In addition, it is used as analytical reagents, solvents and dehydration condensing agent. It serves as an intermediate of fluorine fine chemicals, pharmaceuticals and agrochemicals.
Trifluoroacetylating agent for protection of alcohols and amines: Helv. Chim. Acta., 37, 443 (1954); Tetrahedron, 43, 5583 (1987); Tetrahedron Lett., 28, 4737 (1987), useful, e.g. as volatile derivatives in GC: J. Chromat., 43, 129 (1969); 61, 225 (1971); 93, 223, 447 (1974); D. R. Knapp, Handbook of Analytical Derivatisation Reactions, Wiley, N.Y. (1979); Handbook of Derivatives for Chromatography, 2nd ed., K. Blau and J. M. Halket, Eds., Wiley, Chichester (1993).
Trifluoroacetyl esters are rapidly hydrolyzed at pH 7: Tetrahedron Lett., 1039 (1963). Trifluoroacetamides are also readily hydrolyzed e.g. by mild base; selective cleavage of a trifluoroacetamide can be achieved in the presence of a methyl ester: J. Org. Chem., 54, 2498 (1989). For the racemization-free removal of the N-trifluoroacetyl group from peptides by NaBH4, see: Chem. Ber., 103, 2437 (1970).
In pyridine and dichloromethane or ether, converts acid chlorides to trifluoromethyl ketones in good yields via a trifluoroacyl ketene intermediate: Tetrahedron, 51, 2573 (1995). The method has been extended to the synthesis of a range of trifluoromethylated heterocycles: Tetrahedron, 51, 2585 (1995):
Mild conversion of aryl halides to aryl trifluoromethyl ketones via Pd catalyzed stannylation: Synlett, 165 (1995).
In pyridine, dehydrates carboxamides or aldoximes to nitriles: Tetrahedron Lett., 1813 (1977); Synthesis, 56, (1979). With triethylamine, effects the dehydration of aldols to enones, where other methods are less successful: Org. Synth. Coll., 8, 210 (1993).
For the ɑ-trifluoroacetylation of a phosphonium salt in a route to perfluoroalkyl acetylenes, see: Org. Synth. Coll., 9, 436 (1998). For reaction scheme, see (Ethoxycarbonylmethyl)triphenylphosphonium bromide, A16347.
Alternative to Oxalyl chloride, A18012, for activation of Dimethyl sulfoxide, A13280 in the low temperature Swern oxidation of alcohols to aldehydes or ketones: J. Org. Chem., 41, 957 (1976); Tetrahedron, 34, 1651 (1978). This reagent often gives cleaner reactions and improved yields, e.g. in the synthesis of a sensitive 1,2-dione from the diol: J. Org. Chem., 52, 4851 (1987).
Jones, D. H.; Smith, K.; Elliott, M. C.; El-Hiti, G. A. Factors affecting reactions of trialkylcyanoborates with imidoyl chlorides/trifluoroacetic anhydride. Tetrahedron 2015, 71 (36), 6285-6289.
Shibakami, M.; Tsubouchi, G.; Sohma, M.; Hayashi, M. One-pot synthesis of thermoplastic mixed paramylon esters using trifluoroacetic anhydride. Carbohydr. Polym. 2015, 119, 1-7.
Hazard Statements: H332-H314-H318
Harmful if inhaled. Causes severe skin burns and eye damage. Causes serious eye damage.
Precautionary Statements: P260u-P303+P361+P353-P305+P351+P338-P301+P330+P331-P405-P501a
Do not breathe dusts or mists. IF ON SKIN (or hair): Remove/Take off immediately all contaminated clothing. Rinse skin with water/shower. IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. IF SWALLOWED: Rinse mouth. Do NOT induce vomiting. Store locked up. Dispose of contents/container in accordance with local/regional/national/international regulations.