Poly(N-vinylimidazole) as an efficient and recyclable catalyst of the aza-Michael reaction in water

Poly( N -vinylimidazole) effectively catalyzed Michael addition of 1 H -1,2,4-triazole, 3,5-dimethyl-1 H -1,2,4-triazole, uracil, oxazolidin-2-one, and succinimide to but-3-en-2-one, cyclohex-2-en-1-one, methyl acrylate, and methyl vinyl sulfone in water at room temperature. The catalyst can readily be regenerated and repeatedly used at least five times without loss in activity, as shown in the reaction of 1 H -1,2,4-triazole with but-3-en-2-one as an example.