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

Abstract

Poly(N-vinylimidazole) effectively catalyzed Michael addition of 1H-1,2,4-triazole, 3,5-dimethyl-1H-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 1H-1,2,4-triazole with but-3-en-2-one as an example.

Poly(N‐vinylimidazole)‐l‐poly(tetrahydrofuran) amphiphilic conetworks and gels. II. Unexpected dependence of the reactivity of poly(tetrahydrofuran) macromonomer cross‐linker on molecular weight in copolymerization with N‐vinylimidazole

“…Due to the unique chemical and physicochemical properties of this heterocycle, imidazole containing polymers, especially PVIm and copolymers thereof and poly(benzimidazole)s, have become attractive materials for a variety of purposes in the last couple of years. 1,[45][46][47][48][49][50][51] These are also well demonstrated in recent overviews by Long and coworkers 52 on imidazole containing polymers and by Yuan and Antonietti 53 on polyionic liquids. On the other hand, PTHF is one of the best biocompatible elastic polymers 54 and also a component of various commodity products.…”

“…Imidazole and its derivatives play a crucial role in primary biomacromolecules, such as DNA, RNA, and proteins and also in pharmaceutical and several other compounds, such as ionic liquids, N ‐heterocyclic carbenes, and so forth. Due to the unique chemical and physicochemical properties of this heterocycle, imidazole containing polymers, especially PVIm and copolymers thereof and poly(benzimidazole)s, have become attractive materials for a variety of purposes in the last couple of years 1, 45–51. These are also well demonstrated in recent overviews by Long and coworkers52 on imidazole containing polymers and by Yuan and Antonietti53 on polyionic liquids.…”

Recyclable Nanostructured Catalytic Systems in Modern Environmentally Friendly Organic Synthesis

“…Michael addition of a number of NH-acids (azoles) [ 32 ] ( Scheme 10 ) and CH-acids [ 33 ] ( Scheme 11 ) proceeded analogously to give corresponding products with high yields.…”

Poly(N-‎vinylimidazole): A ‎biocompatible‎, efficient, and ‎highly ‎‎recyclable ‎heterogeneous ‎catalyst for ‎the ‎preparation of ‎bis(3-‎‎indolyl)methanes ‎

“…PVIm, as a pH-sensitive functional polymer, can be protonated at acidic pH and de-protonated under basic conditions [32]. PVIm and its copolymers have been applied in the suppressing gene expression, as drug and protein delivery carriers [31], heavy metal removal via metal-binding chelating [33,34], catalysis [35][36][37][38], pervaporation [39], fuel cell [40], CO2 separation [41], and nanofiltration separation [42].…”