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Deep eutectic solvents (DESs) and ionic liquids (ILs) are potential solvents for lignocellulosic biomass fractionation. In this study, the rice straw pretreatment efficiency of four cholinium-based solvents (DESs and ILs) prepared from the same sources (lactic acid and lysine) were comparatively investigated at 110 °C for 4 h. The lignin removal rate correlated well with the saccharification efficiency of the pulps. Quantum chemical (QC) calculations and molecular dynamics (MD) simulations focused on the microscopic structure and non-covalent interactions of the solvents and lignin model molecules (guaiacylglycerol-β-guaiacyl ether, GG) were carried out, and the results indicate that anions of the solvent systems play a leading role (through strong hydrogen bonds or electrostatic interactions) in establishing interactions with GG, supported by cations (via van der Waals interactions). There were clear positive relationships between the total interaction energies (IEs) and lignin removal, cellulose digestibility and glucose yields. In particular, [Ch][Lys] with a low self-interaction energy is able to free some active sites to form strong hydrogen bonds and electrostatic interactions with lignin, thus resulting in lignin dissolution and excellent delignification. For cholinium cations, an ideal partner system provides low self-IEs for solvent molecules and strong IEs between solvents and lignin, which are determined by the type and number of functional groups and the alkyl chain length of the partner components. This work provides ideas about tailoring suitable partner systems for cholinium cations to build solvents for efficient biomass deconstruction. [ABSTRACT FROM AUTHOR]

Millions of tons of solvents are consumed annually in various industrial sectors, such as pharmaceuticals, chemical synthesis, textiles, coatings, paints, and others. Ionic liquids (ILs) are pairs of ions in the liquid form synthesized at temperatures below 100 °C that meet specific demands of processes, replacing organic solvents that are harmful to the environment. They offer exceptional prospects as advanced solvents owing to their unique attributes and remarkable recyclability. However, alkyl imidazolium-based ILs have proven to be flammable when exposed to heat, and cytotoxicity and phytotoxicity were observed for many traditional ILs. Therefore, with a focus on negligible toxicity, biocompatibility, straightforward preparation, and sustainability, biocompatible ionic liquids (Bio-ILs) have emerged with huge potential in many different fields of chemistry. These solvents are specifically designed to be derived from naturally occurring compounds. Their physical–chemical properties, modulated according to the application, make them an attractive green technology. Therefore, this review addresses the recent advances in Bio-ILs that include the production of renewable commodities and approaches in catalysis and the pharmaceutical field. Likewise, patents and future perspectives are discussed, demonstrating the great potential of Bio-ILs as green and sustainable compounds. [ABSTRACT FROM AUTHOR]

Organic azides are widely used in organic synthesis. Continuous flow processing can be used to bypass their isolation, and can therefore be useful in mitigating the hazards associated with these potentially toxic and explosive reagents. Nonaflyl azide has been reported as an effective, bench-stable, and relatively safe diazo transfer reagent that can be useful in the preparation of azides from amines and so avoid the use of alkyl halides. Here we demonstrate the synthesis and purification of nonaflyl azide in continuous flow with isolation of the neat, pure reagent by membrane filtration. The neat reagent was used in the preparation of organic azides from primary amines, and then applied to the synthesis of triazoles. A variety of triazoles, including the antiseizure drug Rufinamide, were prepared from primary amines and alkynes via the CuAAC click reaction in a semi-batch parallel array without isolation of alkyl azide intermediates. A telescoped two-stage continuous flow process was also designed and demonstrated to form triazoles via the same CuAAC reaction, which avoids the handling of the intermediate reactive azides. [ABSTRACT FROM AUTHOR]