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Synlett 2006(1): 0112-0114  
DOI: 10.1055/s-2005-922767
LETTER
© Georg Thieme Verlag Stuttgart · New York

A New and Efficient Method for the Trifluoromethylation of Carbonyl Compounds with Trifluoromethyltrimethylsilane in DMSO

Katsuyuki Iwanami, Takeshi Oriyama*
Faculty of Science, Ibaraki University, 2-1-1 Bunkyo, Mito 310-8512, Japan
Fax: +81(29)2288403; e-Mail: tor@mx.ibaraki.ac.jp;
Further Information

Publication History

Received 29 September 2005
Publication Date:
16 December 2005 (online)

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Abstract

In the presence of MS 4 Å in DMSO, trifluoromethyl­ation of various aldehydes and ketones with trifluoromethyltri­methylsilane (TMSCF3) proceeded very smoothly to give the corresponding trifluoromethylated adduct in good to quantitative yields without a base catalyst.

Key words

trifluoromethylation - trifluoromethyltrimethylsilane - carbonyl compounds - DMSO

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Typical Procedure.
A solution of benzaldehyde (30 µL, 0.30 mmol) and TMSCF3 (54 µL, 0.36 mmol) in DMSO (2 mL) in the presence of powdered MS 4 Å (150 mg) was stirred at r.t. under an argon atmosphere. After 15 min, the reaction mixture was quenched with a phosphate buffer (pH 7, 20 mL). The organic materials were extracted with Et2O, dried over anhyd MgSO4, and the solvent was evaporated in vacuo. 1H NMR analysis (400 MHz) of the crude product using 1,1,2,2-tetrachloroethane as an internal standard shows that (2,2,2-trifluoro-1-phenylethoxy)trimethylsilane was obtained in quantitative yield. The product gave satisfactory 1H NMR, 13C NMR, 19F NMR, and IR spectra after the purification by TLC on silica gel.