Amino acid-based ionic liquids for CO2 conversion to form cyclic carbonate under solvent-free conditions

Oxidized Biochar as a Simple, Renewable Catalyst for the Production of Cyclic Carbonates from Carbon Dioxide and Epoxides

“…The various epoxides screened were all transformed into their respective cyclic carbonate (70-99 % conversion), showing a broad scope for the catalytic system studied. The trend in conversions obtained agrees with the literature, [34,37,[45][46][47] and relates to the electron-withdrawing capacity of the substituents which makes the epoxide more susceptible to nucleophilic attack, giving higher conversions. Due to steric effects, cyclohexene oxide ( Table 2, entry 7) is known to be more challenging to convert to the cyclic carbonate and low conversions are not unexpected.…”

Recent Advances in the Chemical Fixation of Carbon Dioxide: A Green Route to Carbonylated Heterocycle Synthesis

“…There are also some papers that reported only one example of conversion of epoxides into carbonates. Two cases reported in Table 1 are the work of Verpoort on Zn-Co/ZIF (entry 50) [88], because it was then extended to other substrates (entry 51) [89]; and the work of Kleij and co-workers on bifunctional resorcinarenes [74], because they reported the only example for their catalyst on polymeric support (entry 60). Other catalysts have been proposed for CO 2 addition to epoxides in which only one substrate was studied.…”

Hybrid Catalysts for CO2 Conversion into Cyclic Carbonates

“…Several catalysts, working under both homogeneous and heterogeneous conditions, were developed for the conversion of CO 2 into cyclic carbonates via reaction with epoxides. In particular, metal oxides [21], metal-organic frameworks (MOFs) [22][23][24], metal salts [25], metal complexes [12,[26][27][28], Lewis base systems [29], ionic liquids (ILs) [30][31][32][33][34][35], and organic polymers [32,36,37] were proposed as catalysts for this reaction. Based on the environmental impact and the cost efficiency, the overall sustainability of this process has to be evaluated and improved according to some key criteria such as (i) the presence of solvents, (ii) the use of metal species, (iii) the achieved yields and selectivity, and (iv) the required reaction conditions (temperature, pressure, reaction time).…”

“…Yi, Yin, et al reported the preparation through silylanization of two multi-functionalized catalysts 33 and 34 possessing quaternary ammonium iodide moieties (Scheme 25). These catalysts, characterized by the co-existence of quaternary ammonium salts, silanol groups, and primary (33) or tertiary amines (34), were designed for maximizing the synergistic effects between silanol groups and halide ions in activating the ring opening of the epoxides, while ensuring a good adsorption of CO 2 thanks to the action of amine groups with no need for supplementary co-catalysts [98,99]. Both catalysts allowed converting carbon dioxide into cyclic carbonates with an apparent similar catalytic activity within 4 h, using 2 MPa CO 2 at 120 • C for 33 and at 90 • C for 34, and they were reused for five consecutive catalytic cycles without significant loss of activity.…”