REGIOSELECTIVE SYNTHESIS OF EITHER 1H- OR 2H-1,2,3- TRIAZOLES VIA MICHAEL ADDITION TO α,ß-UNSATURATED KETONES.

The Michael reaction of NH-1,2,3-triazole (1) with α,β-unsaturated ketones was studied. 1H-1,2,3-triazolyl-ketones were selectively generated when 1 was combined neat with a variety of enones. The use of aprotic solvents with catalytic base gave the corresponding 2H-regioisomers. Together, these two protocols provide direct access to either the N1- or N2-substituted 1,3-triazolyl ketone regioisomers.