Efficient cycloaddition of CO2 to epoxides using novel heterogeneous organocatalysts based on tetramethylguanidine-functionalized porous polyphenylenes

Benzotriazolium Ionic Liquid Immobilized on Periodic Mesoporous Organosilica as an Effective Reusable Catalyst for Chemical Fixation of CO2 into Cyclic Carbonates

“…On the basis of the above results and those previously reported works, [12][13][14][15][18][19][20][21] a possible mechanism is proposed in Scheme 2. First, epoxide could be activated through the coordination of active nickel anion and hydroxyl sites of PMO@ILC4H10O2NiCl3(1.0) and the oxygen of epoxide, resulting in the polarization of C-O bond, so as to form the intermediate i, together with the adsorption and activation of CO2 by the benzotriazolium cation to form carbonate species.…”

“…[9,10] However, most of these systems often need solvents or homogeneous additives, high pressures and temperatures. Recently, considerable effort has been devoted to the development of efficient catalytic systems for the synthesis of cyclic carbonates such as nano-PDA/KI, [11] ZnI2/NEt3, [12] (Cp2TiCl2)/KI, [13] ZnCl2/Al2O3-TBAI, [14] Zn-SBA-15/KI, [15] metal complexes, [16][17][18][19] organocatalysts, [20][21][22] MOFs, [23][24][25] MgO/TBAB/Bu4NBr, [26] Bp-Zn@MA, [27] H-MFeSN, [28] and others. [29][30][31] In spite of their potential utility, however, most of them still have problems such as harsh reaction conditions, use of expensive reagents, cumbersome product isolation and catalyst reusability procedures.…”

Recent developments in organocatalysed transformations of epoxides and carbon dioxide into cyclic carbonates

“…These solids have emerged as favourable heterogeneous catalysts for a number of reactions, due to their convenient separation from the reaction mixture and ability to be recycled. In 2018, three tetramethylguanidine functionalised porous polyphenylenes 64-66 ( Figure 23) were explored for the synthesis of cyclic carbonates from epoxides and carbon dioxide by Iglesias et al 209 Catalyst 66, with a methylene group between the tetramethylguanidine and the polymeric skeleton, showed the best catalytic activity. For the reaction of epichlorohydrin with carbon dioxide catalysed by 66, 100% epichlorohydrin conversion was achieved, after 4 h at 7 bar carbon dioxide and 100 o C using 0.1 mol% of catalyst, with no by-product formation.…”

Mixed Matrix Membranes Containing a Biphenyl-Based Knitting Aryl Polymer and Gas Separation Performance

“…Biphenyl-Based Knitting Aryl Polymer Filler (K2Ph) Two different strategies have been reported for the preparation of knitting aryl polymers: one based on a Friedel-Craft reaction using formaldehyde dimethyl acetal (FDA) as an external cross-linker, FeCl 3 as the catalyst and an 80 • C reaction temperature [17], and the other based on the Scholl reaction, in which a chlorinate solvent acts as both a solvent and cross-linker simultaneously, in the presence of AlCl 3 as the catalyst and a 40 • C reaction temperature [25]. We previously prepared the biphenyl-based knitting aryl polymer filler (K2Ph) using the latter procedure [26]. To explore the effect of changing conditions, for this work K2Ph was prepared using the Friedel-Craft reaction.…”