Bifunctional Ionic Liquids Derived from Biorenewable Sources as Sustainable Catalysts for Fixation of Carbon Dioxide

Abstract

A series of highly efficient, bifunctional ionic liquids containing a quaternary alkyl ammonium cation and an amine anion were prepared from choline and amino acids, respectively. Nine ILs were synthesized, characterized, and applied as organocatalysts for the chemical fixation of carbon dioxide to form cyclic carbonates and quinazoline-2,4(1 H,3 H)-diones. A binary mixture of an IL and a co-catalysts generates deep eutectic solvents (DESs) and accelerates the rate of the cycloaddition reaction at atmospheric pressure and low temperature (70 °C). The presence of the hydroxyl functional group of choline and the free amine group of the amino acids in the ILs has a synergistic effect on the activation of the epoxide and carbon dioxide towards the cycloaddition reactions. These ILs are biodegradable and are synthesized from easily available biorenewable sources. Additionally, this catalytic method demonstrates ultimate environmental benignity because of the mild metal- and solvent-free conditions as well as the recyclability of the catalyst and co-catalyst.

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.…”

“…Treatment of biochar and carbon‐based materials with nitric acid (HNO 3 ) is known to greatly increase the content of oxygenated groups on their surface, introducing more hydroxyl and carboxyl groups. These functional groups are important structural motifs in catalysts for the reaction chosen herein . However, the use of oxidized biochar to remove pollutants is the only application studied to date .…”

“…These functional groups are important structural motifs in catalysts for the reaction chosen herein. [26][27][28][29][30][31][32][33][34][35][36][37] However, the use of oxidized biochar to remove pollutants is the only application studied to date. [24,25] As a catalyst, functionalized biochar containing sulfonic acid groups (SO 3 H) has shown favorable performance in the hydrolysis of biomass, biodiesel production, and in various acid-catalyzed reactions (e. g. acylation of alcohols and amines, and alkylation of aromatics).…”

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).…”

Ru@PsIL‐Catalyzed Synthesis of N‐Formamides and Benzimidazole by using Carbon Dioxide and Dimethylamine Borane

“…In a continuation of our research interest towards the catalytic fixation of CO 2 , herein, we have synthesized and characterized Ru NPs (Ru@PsIL) stabilized onto a supported ionic liquid phase. These as‐synthesized NPs are applied as a multitasking catalyst for the synthesis of formamides, benzimidazoles, and the one‐pot reduction and cyclization of nitroaniline to benzimidazoles under mild conditions (Scheme ).…”