Trifluoromethylation of aldehydes
23 September 2005
The conversion of aldehydes in to trifluoromethyl carbinols usually requires the use of expensive trifluoromethylating reagents, but a new paper describes the use of sodium trifluoroacetate to effect this conversion using stoichiometric amounts of copper catalysts:
A variety of aldehyde substrates (o,m and p-tolualdehydes and o,m and p—chlorobenzaldehydes) give high yields (86-100%) in this reaction.
Cyclohexanecarboxaldehyde also worked well as a substrate (95%), but ketones do not give such high yields. Cyclohexanone and acetophenone are trifluoromethylated in 57% yield and 2% yield respectively.
A number of copper salts, can be used, including CuI, CuBr, CuCl and CuBr².
* Y. Chang and C. Cai, Tet. Letts., 2005, 46, 3161-3164.