Reduction Reactions in Green Solvents: Water, Supercritical Carbon Dioxide, and Ionic Liquids

Abstract

Solving problems: Reduction reactions are important chemical transformations, widely used on both the laboratory and industrial scale. Thus, the importance of these chemical transformations necessitates research towards alternative, greener solvent systems, to reduce any negative impact on the environment. This Minireview is focused on three alternatives for conducting reduction reactions: water, supercritical carbon dioxide, and ionic liquids.

Selective Hydrogenation of Phenol and Derivatives over Polymer‐Functionalized Carbon‐Nanofiber‐Supported Palladium Using Sodium Formate as the Hydrogen Source

“…8–12 However, another important and inherent drawback of current liquid‐phase hydrogenation protocols relates to the use of environmentally unfriendly organic solvents8 and/or expensive and more sophisticated conditions 5. 9 In this regard, a selective phenol hydrogenation in aqueous media is highly desirable, because water is environmentally benign and easily available 13. Moreover, the study of organic reactions in/on water is an important theme of current research from the viewpoint of green and sustainable chemistry.…”

Combination of Imidazolium Bromine and Tetrabutylammonium Bromide for CH4 Purification from Simulated Biogas by Hydrate-Based Gas Separation

“…Compared to traditional inorganic salts, excellent thermodynamic stability, less volatility, and environment-friendliness are superior characteristics of ionic liquids . In the 21st century, H 2 O, supercritical CO 2 , and ionic liquid are considered as three green solvents . In this paper, the influence of ionic liquid [BMIm] Br on hydrate formation and biogas hydrate separation was studied.…”

“…26 In the 21st century, H 2 O, supercritical CO 2 , and ionic liquid are considered as three green solvents. 27 In this paper, the influence of ionic liquid [BMIm] Br on hydrate formation and biogas hydrate separation was studied. TBAB is a thermodynamic hydrate promoter which could form semiclathrate hydrates with water molecules.…”

Beckmann Rearrangement of Ketoxime Catalyzed by N-methyl-imidazolium Hydrosulfate

“…However, it brings equipment corrosion and environmental pollution problems. Recently, ionic liquids [ 17 ] have emerged as potential green alternatives to organic solvents due to their unique properties of low volatility, high polarity, good thermal stability, and excellent solubility [ 18 , 19 , 20 ]. Further, there are more potential capabilities as effective catalysts and reagents [ 13 ], as chemical transformations have also been explored.…”