Recent advances in the application of deep eutectic solvents as sustainable media as well as catalysts in organic reactions

Abstract

Deep eutectic solvents (DESs), also known as deep eutectic ionic liquids (DEILs) or low-melting mixtures (LMMs) or low transition temperature mixtures (LTTMs) in the literature, have become more and more attractive in recent years due to their interesting properties and benefits, such as low cost of components, easy to prepare, tunable physicochemical properties, negligible vapor pressure, non-toxicity, biorenewability and biodegradability. These eutectic mixtures have been widely used as green and sustainable media as well as catalysts in many chemical processes. This review focuses on recent advances using DESs in organic reactions including addition reactions, cyclization reactions, replacement reactions, multicomponent reactions, condensation reactions, oxidation reactions, and reducing reactions.

Catalytic Conversion of Carbohydrates to Furanic Derivatives in the Presence of Choline Chloride

“…In general, DES is formed as a result of hydrogen-bonding interactions between two components. Therefore, one of the constituents is a hydrogen-bond acceptor (usually ChCl or NH4Cl), whereas the other constituent is a hydrogen-bond donor like natural polyols (glycerol), carboxylic acids (lactic acid (Lac), oxalic acid, citric acid) or ureas [7,8,[10][11][12][13][14][15][16][17]. If carbohydrates are used as hydrogen-bond donors with ChCl, the name used is "low melting mixtures" (Scheme 2).…”

Determination of Trace Rhodamine B in Chili Oil by Deep Eutectic Solvent Extraction and an Ultra High-Performance Liquid Chromatograph Equipped with a Fluorescence Detector

“…[17][18][19] DESs composed of two or three inexpensive and safe components capable of self-association had low melting points compared to their constituting components. As a class of novel green solvents, DESs were applied to many fields, such as organic synthesis and compound separation.…”

Application of Deep Eutectic Solvents in Promiscuous Lipase‐Catalysed Aldol Reactions

“…6 Eutectic mixtures have attracted increasing attention in a variety of fields such as lubricants, 7 nanomaterials, 8 pharmaceuticals 9 and separation techniques. 10 More closely to organic synthetic applications, DES have efficiently catalysed multiple traditional organic 11 and organometallic reactions, 12 but the application in biocatalysed transformations is still rare. 13 Until now, the activities of hydrolases, 14 oxidoreductases 15 and lyases 16 have been already demonstrated in high-yielding transformations using DES as medium.…”