In situsynthesis of pyridinium-based ionic porous organic polymers with hydroxide anions and pyridinyl radicals for halogen-free catalytic fixation of atmospheric CO₂

Abstract

Pyridinium-based ionic porous organic polymers (Py-iPOPs) were constructed from newly-designed acetonitrile-functionalized ionic liquids and multi-carbaldehyde monomers by the base-catalyzed Knoevenagel condensation. The obtained Py-iPOPs having in situ formed hydroxide anions...

Simple Halogen‐Free, Biobased Organic Salts Convert Glycidol to Glycerol Carbonate under Atmospheric CO2 Pressure

“…Similar considerations can be done for the cobalt‐based porous polymer functionalized with imidazole moieties that was reported to catalyze the formation of 1 b under atmospheric pressure at 100 °C and with good but incomplete 1 a conversion using relatively poisonous cobalt as a Lewis acidic metal (Table S10, entry 12) [85] . Finally, excellent 1 a conversions and 1 b selectivities were reported by Chen and co‐workers using a pyridine‐based porous organic polymer under mild conditions (60 °C, 1 bar) but these experiments required a much longer reaction time (48 h), and the authors utilized a considerably higher mass of synthetic polymer per mole of 1 a (Table S10, entry 13) than in our case [86] . Under these conditions, this catalyst also showed excellent recyclability with glycidol as the substrate (Table S10, entry 14), however, its preparation required relatively expensive and hazardous halogenated monomers and a lengthy procedure.…”

“…Concerning the comparison of the catalytic performance of sodium alginate with halogen‐free, single‐component catalysts for the solvent‐free cycloaddition of CO 2 to 1 a (See Table S10, entries 7–14 for details), it should be emphasized that, to the best of our knowledge, no equivalent fully bio‐based heterogeneous catalyst was previously employed for the target reaction. Selected relevant literature systems include inorganic or hybrid materials such as nanocrystalline Li‐MgO, [83] a tungsten heteropolyacid‐based ionic liquid immobilized on fibrous nanosilica (HPA@KCC‐1), [84] as well as metal‐based (Co), [85] or metal‐free and pyridine‐derived porous organic polymers with hydroxy anions [86] . Among the above‐mentioned reported catalysts, the inorganic or hybrid materials afforded high to nearly complete 1 a conversions (with unspecified selectivity) in short reaction times (1.5–4 h), but these reactions required harsher reaction conditions (90 °C, 10 bar for HPA@KCC‐1; [84] 130 °C, 30 bar for nanocrystalline Li‐MgO [83] ) than for sodium alginate (80 °C, 1–5 bar; see Table S10, entries 7–11).…”

“…Selected relevant literature systems include inorganic or hybrid materials such as nanocrystalline Li-MgO, [83] a tungsten heteropolyacid-based ionic liquid immobilized on fibrous nanosilica (HPA@KCC-1), [84] as well as metal-based (Co), [85] or metal-free and pyridine-derived porous organic polymers with hydroxy anions. [86] Among the above-mentioned reported catalysts, the inorganic or hybrid materials afforded high to nearly complete 1 a conversions (with unspecified selectivity) in short reaction times (1.5-4 h), but these reactions required harsher reaction conditions (90 °C, 10 bar for HPA@KCC-1; [84] 130 °C, 30 bar for nanocrystalline Li-MgO [83] ) than for sodium alginate (80 °C, 1-5 bar; see Table S10, entries 7-11). While reusable, the recyclability of the latter catalysts was not tested using 1 a as the substrate and, therefore, it is not possible to assess whether also in those cases the 1 b selectivity would be affected through catalyst recycling.…”

“…[85] Finally, excellent 1 a conversions and 1 b selectivities were reported by Chen and co-workers using a pyridine-based porous organic polymer under mild conditions (60 °C, 1 bar) but these experiments required a much longer reaction time (48 h), and the authors utilized a considerably higher mass of synthetic polymer per mole of 1 a (Table S10, entry 13) than in our case. [86] Under these conditions, this catalyst also showed excellent recyclability with glycidol as the substrate (Table S10, entry 14), however, its preparation required relatively expensive and hazardous halogenated monomers and a lengthy procedure. Overall, this generic catalytic comparison shows that metal alginates stand out as an advantageous choice for the preparation of 1 b in terms of sustainability, cost, and high availability with reasonable catalytic activity under mild conditions.…”

Bifunctional metal–organic frameworks afforded by postsynthetic modification for efficient cycloaddition of CO2 and epoxides

“…[16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] Among these conversion, the CO 2 cycloaddition from CO 2 and propylene oxide (PO) to propylene carbonate (PC) is of great interest. [24][25][26][27][28][29][30][31][32] The conversion shows 100% atom economy, and the products (PC) are widely used as electrolytes, polar solvent, pharmaceuticals, and intermediates in some organic reactions. [33][34][35][36] However, due to the intrinsic chemical inertness of CO 2 , its high efficient conversion is still a great challenge.…”