Themed collection 2022 Green Chemistry Hot Articles

This paper reviewed the entire life cycle of plastics and options for the management of plastic waste to address barriers to industrial chemical recycling and further provide perceptions on possible opportunities with such materials.

This review highlights the use of Cyrene as an alternative green solvent in organic synthesis.

Supramolecular Deep Eutectic Solvent (SUPRADES) – another milestone towards Green Chemistry.

Porous poly(ionic liquid)s, combining the features of porous polymers and ionic moieties resembling the structures and functions of ionic liquids, have exhibited promising potential in CO₂ fixation via cycloadditions with epoxides.

This review focuses on the applications of emerging carbon-based QD materials (i.e., GQDs, CNQDs, MQDs, and GDQDs) in sustainable photocatalysis.

Mapping of the thermal, mechanical and (bio)degradation properties of fossil and bio-based polymers. When recycling fails, criteria and scenarios where (bio)degradable polymers are beneficial, for a sustainable development, were critically discussed.

Recent research progress on the electro-oxidative depolymerization of lignin for the production of value-added products has been reviewed, focusing on the catalysts, electrodes, processes, electrocatalytic system and additives.

This review summarizes the research progress in the one-pot catalytic amination of lignin oxygenated model compounds to cyclohexylamine, specifically from the catalyst nanostructure engineering and catalytic conditional strategy.

This review summarizes a variety of catalytic systems to achieve the selective hydrodeoxygenation of potent biomass-derived platform chemicals with a focus on features including catalytic performance, active sites, and mechanism.

This review of the metal- and organo-catalyzed coupling of CO₂ and epoxides (oxiranes) to provide selectively cyclic or polymeric carbonates is intended to highlight recent achievements in this area of research.

The existing literature has been summarized and synthesized, providing a new outlook for the preparation of 2-methyltetrahydrofuran from biomass substrates using precious and non-precious metal catalysts.

Confinement effects offer unique opportinuties to facilitate reactions in a way to favor sustainability... in an almost magical way.

The development of new biological routes for 1,3-propanediol production from diversified substrates using engineered producers, new chassis, and new pathways.

Developing greener synthesis processes is an inescapable necessity to transform the industrial landscape, mainly in the pharmaceutical sector, into a long-term, sustainable reality.

A photocatalyst-free visible-light-promoted remote C(sp³)–H heteroarylation of N-fluoroamides with quinoxalin-2(1H)-ones was developed. All types of δ-C(sp³)–H bonds in the N-fluoroamides could be site-specific activated through the 1,5-HAT process.

An integrated organic electrosynthesis system was developed with a phase-separated membrane-electrode assembly strategy, coupling in situ electrochemical H₂O₂ production and olefin epoxidation, with only H₂O and O₂ consumption under ambient conditions.

A new, metal-free, and highly atom economical strategy for the difunctionalization of unactivated alkenes under mild conditions.

This work details the effect of common antioxidants on the activity and functionality of a hydrocracking catalyst, along with associated changes to the product distribution in the deconstruction of high-density polyethylene.

An unprecedented visible-light-driven regioselective carbocarboxylation of 1,3-dienes with CO₂ using aryl and alkyl halides under mild conditions is reported herein.

We introduced a combination of simple graphite electrodes, mild conditions, and a simple workup procedure for the selective preparation of sulfides or sulfoxides via unactivated olefins and thiophenols through a green electrochemical protocol.

A novel TsCl-mediated domino sequence to expeditiously access quinolone-based antibiotics, starting from commercially available chromone-3-carboxaldehydes and amines, was developed under environmentally benign conditions.

The electrochemical annulation of enaminones/analogous enamines and thioureas providing 2-aminothiazoles has been realized. Modulating the electrolyte enables the diastereoselective synthesis of 4,5-dialkoxyl thiazolines by dearomatization.

A photochemical ring contraction is reported for the synthesis of oxetanes from dihydrofurans and diazo compounds under catalyst-free conditions.

Xylose is converted to a new type of bisfuranic compound in nearly quantitative yield with acetylacetone, through a Zr-catalysed Garcia Gonzalez reaction-based strategy by losing five molecules of water.

Photoinduced tandem cyclization of alkynes with NH₄SCN was developed for the synthesis of various SCN-containing seven-membered N-heterocycles.

The in situ generation of H₂ from aluminum powder and water/KOH enabled a general hydrogenation method in cholinium chloride/glycerol deep eutectic solvent under Pd/C catalysis.

As an important step towards circular value-chains for bioplastics, we report a strategy for the direct catalytic processing of two biopolyesters.

Two unprecedented reactions using alkynyl 1,2-diketones and 1,3-dicarbonyls under phosphine catalysis have been achieved, furnishing a range of acyloxy allylidene malonates and γ-alkylidenebutenolides in good yields with high stereoselectivities.

For the first time, the design of a urea : zinc acetate DES for a continuous, eco-friendly and closed-loop approach for recycling poly(ethylene 2,5-furandicarboxylate) (PEF) is communicated to avoid its future accumulation in the environment.

Diverse peptidomimetics containing N,O- or N,S-aminals are synthesized via a transition metal-free C–S bond cleavage and subsequent Mannich reaction.

An efficient transition-metal-free hydrodefluorination reaction of trifluoromethyl alkenes for accessing gem-difluoroalkenes is developed. It was surprising to find that the phosphoryl anion is able to mediate the defluorination.

No preactivation or coupling to high-energy reagents is required for the dearomative coupling of benzylmalonates and acetylenes, although the transformation has no significant thermodynamic driving force.

A simple procedure for the one-pot synthesis of 2,5-furandicarboxylic acid dimethyl ester (FDME) from galactaric (mucic) acid via dimethyl carbonate (DMC) chemistry is presented. The compound was isolated as a white powder in 70% yield.

CO₂ could be efficiently converted into C₂₊ products over a fluorine doped Cu catalyst, with high faradaic efficiency (70.4%) and current density (above 400 mA cm⁻²), which benefited from the boost the adsorption of CO intermediate.

Alcohols with different chain lengths can react with CO₂ and H₂ to produce C₁-elongated carboxylic acids using an Ir catalyst.

A novel electrochemical strategy for the synthesis of valuable isoindolinones has been developed with the use of simple o-alkylbenzoic acid and alkyl nitrile as starting materials under metal-catalyst and external oxidant-free conditions.

The regulation of morphology and wettability of Zn films is an efficient strategy for producing syngas with a wide CO/H₂ ratio range from electrochemical CO₂ and H₂O reduction.

A NbO_x catalyst with oxygen vacancies is synthesized and used for nitrate electroreduction to ammonia. The faradaic efficiency of 94.5% and the NH₃ formation rate of 55.0 μg h⁻¹ mg_cat⁻¹ can be achieved in a neutral electrolyte.

A visible light-induced organophotocatalytic silyl transfer strategy of silylboranes for the construction of C–Si bonds has been demonstrated, where methanol association with boron atoms enables the photocatalytic generation of silyl radicals.

Life cycle assessment as a decision-making tool in R&D of CO₂ conversion technologies. A set of technologies are explored to provide recommendations regarding potential climate impacts. Relevant fundamentals of this type of assessment are provided.

we present a highly efficient catalytic strategies which are capable of converting DMBQ obtainable from high molecular-weight lignin-oil into industrially highly relevant and well-defined 1,4-cyclohexanediol and 1,4-cyclohexanediamine.

The halogen-bond-assisted C–C activation of alkanols to synthesize a library of alkyl halides in the absence of catalysts and oxidants is disclosed, wherein inexpensive N-haloimides were explored as bifunctional reagents.

New insights into amide-esterification during urethane alcoholysis are presented, and they enable chemical-full-recycling of blended fabric waste.

Bean dregs were exploited as a green reducing agent, and adopted an enhanced recycling process combining biomass reduction roasting and carbonated water leaching to efficiently and selectively recover Li from the spent LIBs.

A green, high yield and scalable strategy to exfoliate covalent organic framework powders using bi-functional ionic liquids in water was developed under ambient conditions.

The in situ synthesis of H₂O₂ offers an attractive alternative to the current industrial route to cyclohexanone oxime, a major precursor to Nylon-6.

A recombinant S. cerevisiae strain was engineered to produce resveratrol from many carbon sources, including xylose, which was used for the synthesis of resveratrol from different wine wastes like vine pruning residue, grape must and wine lees.

Life Cycle Assessment (LCA) and Techno-economic Assessment (TEA) are crucial for a comprehensive evaluation of the novel high-performance thermoplastic polymer polyoxazolidinone (POX).

Tetrahydropyran (THP) is a five-carbon heterocyclic ether that is non-carcinogenic, non-peroxide forming, biodegradable, and economically competitive with tetrahydrofuran (THF) as a solvent.

Corn fibre agricultural side streams can be upgraded into radical scavenging hydrogels with protective effects against cellular oxidative stress using mild biocatalytical processes.

Herein a one-pot double C–H functionalization for constructing C8-alkyl substituted coumarins from phenols is reported. For the first time Pd/C as heterogenous catalyst was used to enable the synthesis of structurally divers coumarins.

A microbubble enhanced CO₂ gas–liquid reactive crystallization process for the one-step preparation of battery-grade Li₂CO₃ has been proposed. The LiFePO₄ cathode synthesized from battery-grade Li₂CO₃ exhibits a remarkable specific capacity.

Non-biodegradable polymers are released as microplastics into the environments during the biodegradation of partially biodegradable polymer blends.

When excess base is required to drive desired reactions, such as in lignin alkaline oxidation, Sr(OH)₂ can offer a reversibly-soluble alternative to NaOH that allows simple recycle of the excess base with concomitant cost and environmental benefits.

Natural antioxidants, such as vitamin E and eugenol, once grafted to silicone oils maintain their antioxidant activity and dilute the quantity of silicone needed for a given application.

A series of hyper-crosslinked POPs were constructed by Friedel–Crafts alkylation reaction of 4CzIPN with FDA, which contains a certain quantity of hydrophilic ether residues to facilitate visible-light-promoted aqueous organic transformations.

Chemical upcycling of PLA:  Ethanolamine cleaves polylactic acid to high purity N-LEA. N-LEA reacts with methacrylic anhydride (MAh) yielding crosslinkable DME. Simply combine DME with reactive diluent and photo-initiator to form a 3D printing resin.

A techno-economic analysis and life cycle assessment for the process to produce a sweetener and calcium supplement from Greek yogurt acid whey show that this method has high profitability and a lower environmental footprint than other sweeteners.

An electrochemical Minisci reaction involving HAT driven α-C(sp³)–H functionalization of alcohols was achieved. Both primary and secondary alcohols are applicable to provide 3-hydroxyalkylquinoxalin-2(1H)-ones in good yields.

The Rh(III)-catalyzed annulation of 3-arylindazoles with iodonium ylides gave indazole fused dihydrophenanthridinones in excellent yields under mild conditions. The reaction only requires simple work-up procedures, and the catalyst can be recycled.

Aqueous two-phase system (ATPS) extraction combined with a natural deep eutectic solvent (NADES) is an environmentally friendly separation process.

Selection of the appropriate base in Ugi/post-condensation sequences allows the selective syntheses of different ring-size functionalized lactams.

A photocatalyst- and transition-metal-free multicomponent reaction of readily available aldehydes, primary amines and 4-alkyl-1,4-dihydropyridines for the synthesis of secondary amines under visible light irradiation has been accomplished.

The study underscores the development of an efficient electrochemical process for anodic H₂O₂ production in continuous flow by investigating electrochemical cell setup, electrolyte flow type and rate, as well as electrolyte composition.

Physical plasma as novel possibility for the synthesis of organic substances e.g. hydroxylated dimers.

Life-cycle assessment of choline chloride/urea (reline) deep eutectic solvent compared with conventional organic solvents.

Here we describe an efficient and practical method for the conversion of 2-aryl benzylic alcohols into the corresponding chromenes with the synergistic interactions of 2-bromoanthraquinone, O₂, nBu₄NBr and K₂CO₃ under visible-light irradiation.

This work demonstrates alternative green ammonia processing using nitrogen and water based non-thermal plasma without pure hydrogen supply which results in an enormous amount of CO₂ emission.

The flow process of recycling a degraded LiFePO₄ cathode.

Redox-neutral ketyl couplings: a metal- and additive-free ConPET photocatalytic system allows highly efficient coupling/cyclization of N-aryl acrylamides and carbonyls with formal 100% atom economy.