Khodakivskyy P. Synthesis and reactions of 2-trifluoroacetyl-1,3-azoles

The thesis deals with the synthesis of 2-trifluoroacetyl-1,3-azoles and their electrophilic reactions leading to CF3-containing heterocyclic compounds of potential biological interest. 2-Trifluoroacetyl-1,3-azoles were obtained from the corresponding 1,3-azoles trifluoroacetic acid anhydride and triethylamine and the scope of this method was estimated. 1,1-Dihetaryl-2,2,2-trifluoroethanols were formed as side products in trifluoroacetylations of some 1,3-azoles. The reaction of 2-trifluoroacetyl-1,3-azoles with water, hydroxylamine, and aliphatic amines readily gives stable heminal diols and hemiaminals. NMR spectroscopy has revealed that the electronegativity of the hetaryl ring increases the stability of the heminal diols. 2-Trifluoroacetyl-1,3-azoles readily react with aliphatic CH-acids to give the corresponding aldols. Unlike common ketones, the studied trifluoromethyl ketones easily undergo Baylis-Hillman reaction with methyl acrylate and acrylonitile as well as non-catalytic C-oxyalkylation with electron-rich arenes and hetarenes. The para-/ortho- selectivity in the C-oxyalkylation of anilines was found to be controlled mainly by steric effects. Under harsh conditions the most electrophilic ketones undergo ene reaction with allylbenzene.