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In this work, a class of transition metal-modified MCM-41 mesoporous silica supported ionic liquids nanocatalysts were constructed and efficiently used as catalysts for the effective carboxylation of terminal alkynes through CO2 utilization. The main factors affecting the catalytic performance of carboxylation and its possible reaction mechanism were sufficiently discussed. The results showed that when the dosage was 0.2 g, the temperature was 40°C and the CO2 pressure was 0.3 MPa, the supported catalyst MCM-41@IL-Sm showed the optimal catalytic efficiency. The novel catalyst proved to be highly efficient for the sustainable synthesis of alkynyl carboxylic acids attributing good to excellent yields of 82%–95% within 7–12 h. Moreover, MCM-41@IL-Sm could be recycled and reused six times without noticeable decrease in catalytic activity from two-phase system under external heterogeneous field. The application of supported ionic liquids in the field of carbon dioxide carboxylation has injected a new power source for the efficient and effective production of value-added chemicals from waste CO2. [ABSTRACT FROM AUTHOR]

Global warming and climate change concerns are triggering worldwide interest for sustainable transformation of CO2 into useful chemicals. Here, a new and efficient multifunctional catalytic system for the cycloaddition of carbon dioxide with epoxides to synthesize cyclic carbonates under mild and solvent-free reaction conditions has been developed. The catalytic tests revealed that [P12,4,4,4]Br/MIL-53(Cr) (MIL: Materials of Institut Lavoisier) was the best and powerful catalytic system in the cycloaddition with excellent yields (96-99%) under solvent-free condition and 100 °C, 1.0 MPa for 2-3 h. The synergistic effect of anion and cation of ionic liquid [P12,4,4,4]Br as well as the chromium site of cocatalyst MIL-53(Cr) contributed to the excellent catalytic activity. The present catalytic system has several unique features such as simple operation, good to excellent yields, high catalytic activity, environmentally benign and safe. This study provides a sustainable and efficient synergistic strategy for chemical carbon dioxide fixation via the combination of ionic liquids and metal-organic frameworks. [ABSTRACT FROM AUTHOR]

A series of functionalized ionic liquids immobilized onto SBA‐15 mesoporous materials were prepared, characterized and evaluated as catalysts in cycloaddition of CO2 to epoxides. Most of these immobilized ILs perform well in the reaction, especially the multifunctional titanium incorporated SBA‐15 immobilized heterogeneous catalysts Ti‐SBA‐15@ILClCH2COO(0.5) and Al‐SBA‐15@ILClCH2COO(0.5). The catalytic tests revealed that Ti‐SBA‐15@ILClCH2COO(0.5) was the best and powerful catalyst in the cycloaddition for the preparation of cyclic carbonates with high to excellent yields. The heterogeneous catalyst can be easily separated from the reaction mixture by filtration and reused in six consecutive cycles without significant loss in catalytic activity. The studies demonstrate that the well designed supported catalysts via cooperative catalysis of the supported carrier, anion sites of ILs is a promising platform for construction of novel and highly efficient catalytic transformation systems. [ABSTRACT FROM AUTHOR]

An ionic liquid is used as a catalyst for the synthesis of cyclic carbonates (III) from epoxides (I) and carbon dioxide. [ABSTRACT FROM AUTHOR]

Periodic mesoporous organosilica (PMO) supported ionic liquids with high catalytic ability were prepared and tested in synthesis of 2‐oxazolidinones from the three‐component cycloaddition reactions of CO2, aryl amines and epoxide. The functionalized PMO material PMO@TZ‐ILSmCl4 revealed the most excellent catalytic performance than PMO@TZ‐ILLaCl4 during the catalytic synthesis of 2‐oxazolidinones. Different parameters such as catalyst loading, temperature, CO2 pressure and reaction time were also investigated. Good to excellent yields for 2‐oxazolidinones and stable reusability were reached in the CO2 cycloaddition under solvent‐ /ligand‐free conditions. This work provides a useful route to design novel and highly efficient catalytic systems for the transformation of CO2 into other valuable 2‐oxazolidinones. [ABSTRACT FROM AUTHOR]

Novel periodic mesoporous organosilica supported nanocatalysts with different loading levels of a bis(trifluoromethylsulfonyl)imide anion-based dual imidazolium ionic liquid have been prepared and evaluated as efficient catalysts for the cycloaddition of CO2 to epoxides. The as-fabricated PMO@IL-NTf2(1.0) exhibited the best catalytic performance with excellent conversions (98–100%) and yields (96–99%) at 90 °C and 0.6 MPa for 0.5–1 h, based on a synergistic effect between the dual nucleophilic anion sites of the imidazolium ionic liquid and the hydroxyl group sites of periodic mesoporous organosilica. The excellent recyclability and operational simplicity make this protocol economic and environment-friendly. [ABSTRACT FROM AUTHOR]