2-(Trifluoroacetyl)-1,3-azoles readily react with methyl acrylate and acrylonitrile under Baylis-Hillman reaction conditions to afford heterocyclic trifluoromethyl-containing allylic alcohols in 36-97% yields. The thus obtained Baylis-Hillman adducts readily undergo Michael addition reactions with various nucleophiles.
A facile method of trifluoroacylation of imidazoles, 1,3-thiazoles, and 1,3-oxazoles with trifluoroacetic anhydride resulted in a set of heterocyclic trifluoromethyl-containing ketones. Unlike common ketones, these compounds form stable hydrates and enter into noncatalytic ene reactions with terminal olefins affording the corresponding allyl alcohols.
A set of highly electrophilic 2-trifluoroacetyl-1,3-heterazoles demonstrated excellent activity in the C-hydroxyalkylation of 1H-indole. The reaction conditions and yields of the corresponding trifluoromethyl-substituted alcohols depend strongly on the electron-withdrawing nature of the 1,3-heterazole unit.