Visible‐Light‐Mediated Amide Synthesis in Deep Eutectic Solvents

Abstract

In the present study, for the first time environmentally friendly deep eutectic solvents (DESs) are used as reaction media to perform an efficient, simple and straightforward photocatalytic amide synthesis at room temperature using thioacids and amines. This method features mild conditions, a broad substrate scope, high yields (≤99%) under ambient conditions with air and moisture tolerance. Moreover, the applied operationally mild reaction conditions tolerate the presence of several different functional group substituents on the amine counterpart. Finally, the developed approach allows the recycling of the reaction medium and catalyst for at least three consecutive cycles without a significant decrease in the reaction yield.

On the fate of deep eutectic solvents after their use as reaction media: the CO2 production during downstream and ultimate disposal

“…The starting point would be to consider a (bio)catalytic process using DES as reaction media. Given the outstanding capacity of DES to dissolve substrates with even impaired solubility, [1][2][3][4][5][6][7][8][9][10] it is assumed that a relatively high loading of 100 g substrate per L DES can be established, and that full conversion is achieved in the reaction. As functional unit for the assessment, the production of one kilogram of product can be considered.…”

“…Deep Eutectic Solvents (DES) have emerged over the last two decades as promising solvent systems that have found (academic) applications in many chemical segments, with use as reaction media, extractive agents, performance additives, etc. [1][2][3][4][5][6][7][8][9][10] As remarkable features, DES oen exert low vapour pressure, can be composed of biogenic materials, and display large tuneability, as their physical-chemical properties depend primarily on the precise combination of their components. In the quest for greener solvents that can replace other more hazardous options, DES have served as inspiration, and the eld has broadly ourished.…”

Reactive deep eutectic solvents for EDC-mediated amide synthesis

“…Recently, we have made a significant contribution by introducing a pioneering approach for synthesizing amides from thioacids, by using visible light irradiation under mild conditions in DESs. 31 Hence, as a part of our ongoing interest in the preparation of DESs and investigation of their application in organic synthesis, 32 we investigated the possibility to use RDESs for the N -amidation of amines with carboxylic acids. RDESs have been designed in order to contribute actively to the synthetic process, using choline chloride as the hydrogen-bond acceptor and various carboxylic acids as hydrogen-bond donors.…”

Reactive Deep Eutectic Solvent for an Eco-Friendly Synthesis of Cellulose Carbamate

“…Ionic liquids (ILs), which are traditionally considered environmentally friendly and very versatile non-conventional solvents for chemical transformations [ 33 , 34 , 35 , 36 , 37 ], have limitations in terms of biodegradability and sustainability [ 38 , 39 , 40 , 41 ]. Recently, Deep Eutectic Solvents (DESs) have gained attention as potential green solvents for biomass processing, offering biocompatibility and applications in bio-pharma industries [ 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 ]. Several studies have emerged in which DESs are used as solvents for the derivatization of cellulose and to produce various types of nanocelluloses [ 54 , 55 , 56 , 57 ].…”