Trifluoroacetone Explained

Trifluoroacetone (1,1,1-trifluoroacetone) is an organofluorine compound with the chemical formula CF3C(O)CH3.[1] The compound is a colorless liquid with chloroform-like odour.[2]

Preparation, reactions, uses

Trifluoroacetone is produced from trifluoroacetoacetic acid, which is generated by condensation of ethyl trifluoroacetate and ethyl acetate:

Hydrolysis of the keto-ester, followed by decarboxylation affords trifluoroacetone:

Alternatively, addition of methylmagnesium iodide to trifluoroacetic acid gives the ketone according to this idealized equation:[2]

Reactions

Many studies report on the reactions of trifluoroacetone.[3] It is less prone to hydrate than hexafluoroacetone and more electrophilic than acetone itself. Unlike both of those ketones, trifluoroacetone is prochiral.

Hydrogenation of trifluoroacetone over platinum catalyst gives trifluoroisopropanol. The reduction can also be achieved asymmetrically. Similarly, alkylation with Grignard reagents provides a route to tertiary alcohols. Alkylation and arylation can be achieved using malonate anions and arenes/AlCl3, respectively.

Trifluoroacetone has been converted to the dioxirane using oxone.

It serves as an oxidizing agent in Oppenauer oxidation.[4]

Trifluoracetone is also used in a synthesis of 2-trifluoromethyl-7-azaindoles starting with 2,6-dihalopyridines. The derived chiral imine is used to prepare enantiopure α-trifluoromethyl alanines and diamines by a Strecker reaction followed by either nitrile hydrolysis or reduction.[5]

See also

External links

Notes and References

  1. Web site: 1,1,1-Trifluoracetone 95%. dk.vwr.com. 6 June 2017.
  2. Encyclopedia: Günter Siegemund . Werner Schwertfeger . Andrew Feiring . Bruce Smart . Fred Behr . Herward Vogel . Blaine McKusick . Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH. Weinheim. 2002. 10.1002/14356007.a11_349. 978-3-527-30673-2. Fluorine Compounds, Organic.
  3. Book: 10.1002/047084289X.rn01348 . 1,1,1-Trifluoroacetone . Encyclopedia of Reagents for Organic Synthesis . 2011 . Prakash . G. K.Surya . Wang . Fang . 978-0-471-93623-7 .
  4. Mello. Rossella. Martínez-Ferrer. Jaime. Asensio. Gregorio. González-Núñez. María Elena. Oppenauer Oxidation of Secondary Alcohols with 1,1,1-Trifluoroacetone as Hydride Acceptor. J. Org. Chem.. 2007. 24. 72. 9376–9378. 10.1021/jo7016422. 17975928.
  5. Web site: Concise synthesis of enantiopure alpha-trifluoromethyl alanines, diamines, and amino alcohols by the Strecker-type reaction.. sigmaaldrich.com. 6 June 2017.