Highly efficient fixation of carbon dioxide to cyclic carbonates with new multi-hydroxyl bis-(quaternary ammonium) ionic liquids as metal-free catalysts under mild conditions

The Role of Water Revisited and Enhanced: A Sustainable Catalytic System for the Conversion of CO2 into Cyclic Carbonates under Mild Conditions

“…The use of water as HBD was compared to that of state-ofthe-artH BDs reported in previouss tudies such as phenol, gallic acid, and ascorbic acid under the same reaction conditions ( Table 1, entries [12][13][14][15][16]. Although this comparison demonstrates that water is less effective in promoting the reaction and that am uch higher number of moles of water is needed to achieve similary ields to those obtainedi nt he presence of the above-mentioned organic HBDs (2.8 mmol H 2 O, i.e., 14 mol %r elative to the epoxide,w as neededt om atch the performance of 0.25 mol %o ft hese HBDs), this is counterbalanced by the fact that water is an environmentally friendlier and much less expensive compound.…”

“…[5] Many highly active and selective metal-based catalysts containing Lewis acid sites have been reported, such as metal complexes [10] and metal-organic frameworks (MOFs). [1,12] Several metal-free organic catalysts have also been investigated, such as ammonium halides, [1,[13][14][15] phosphonium halides, [3,16] and imidazolium-basedi onic liquids, [17][18][19] in which the halidesa re the catalytic speciesa cting as nucleophiles. [1,12] Several metal-free organic catalysts have also been investigated, such as ammonium halides, [1,[13][14][15] phosphonium halides, [3,16] and imidazolium-basedi onic liquids, [17][18][19] in which the halidesa re the catalytic speciesa cting as nucleophiles.…”

“…[11] However, metal catalysts tend to display drawbacks such as the generally high cost of their preparation, the toxicity of some metals, and in somec omplexes and MOFs, low stability against hydrolysis and/or oxidation. [1,12] Several metal-free organic catalysts have also been investigated, such as ammonium halides, [1,[13][14][15] phosphonium halides, [3,16] and imidazolium-basedi onic liquids, [17][18][19] in which the halidesa re the catalytic speciesa cting as nucleophiles. These systemsa re less expensive and more readily available than most metal catalysts.…”

Multiobjective Optimization for the Greener Synthesis of Chloromethyl Ethylene Carbonate by CO2 and Epichlorohydrin via Response Surface Methodology

“…Onyenkeadi et al and co-workers reported that formation of oligomers and isomers are possible at extended reaction time at higher temperature. Product quality and stability may also be affected due to chemical degradation or losses by thermal decomposition at higher reaction temperature [66]. Response surface and contour plots of Figure 11 clearly show that CMEC yield had a linear effect with increasing reaction temperature until the optimum condition was achieved.…”

Phosphonium-Based Porous Ionic Polymer with Hydroxyl Groups: A Bifunctional and Robust Catalyst for Cycloaddition of CO2 into Cyclic Carbonates

“…At present, many homogeneous catalytic systems have been developed to promote this conversion. Among them, the homogeneous catalysts based on ionic liquids, such as quaternary ammonium salts [7,8], imidazolium salts [9][10][11], and quaternary phosphonium salts [12][13][14], were demonstrated to be the most efficient. Generally, the homogeneous salts could exhibit high catalytic activity under mild reaction conditions; however, the obvious drawbacks of product separation and catalyst recycling still hamper their large-scale applications.…”