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

• Published in: ChemSusChem Vol. 10; no. 6; pp. 1145 - 1151
• Main Authors: Saptal, Vitthal B., Bhanage, Bhalchandra M.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 22.03.2017
• Subjects: Activation; Amines; Amines - chemistry; biodegradable; Carbon dioxide; Carbon Dioxide - chemistry; Carbonates - chemical synthesis; Carbonates - chemistry; Catalysis; Catalysts; Choline - chemistry; Cycloaddition; cycloaddition reaction; epoxide; Fixation; Green Chemistry Technology; Ionic liquids; Ionic Liquids - chemistry; Quinazolines - chemistry; carbon dioxide; cycloaddition reaction; biodegradable; ionic liquids; epoxide
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.201601228

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. Bifunctional Catalysts! Ionic liquids containing a quaternary alkyl ammonium cation and an amine anion are prepared and applied as organocatalysts for the chemical fixation of carbon dioxide to form cyclic carbonates and quinazoline‐2,4(1 H,3 H)‐diones. The presence of a hydroxyl group and a free amine group in the ILs has a synergistic effect on the activation of epoxides and carbon dioxide and the subsequent cycloaddition reactions.