One story as part of the Global Conversation on Sustainability: dye adsorption studies using a novel bio-derived calcite material.

Many of the United Nations' Sustainable Development Goals (SDGs) can be addressed through chemistry. Researchers at Memorial University of Newfoundland, Canada, have been sharing their stories on September 25 for the past two years through the Global Conversation on Sustainability. This article describes the details of one of these stories. As the global population increases, food production including aquaculture is increasing to provide for this. At the same time, this means more waste is produced. Waste from aquaculture is often overlooked as a source of valuable chemicals. By-products from farming blue mussels (Mytilus edulis) is dominated by shells rich in calcite. A 'soft' calcite material prepared from waste mussels, via a combination of heat and acetic acid treatment, was investigated for its adsorptive properties and its possible use in wastewater remediation. The adsorption of two cationic dyes, methylene blue and safranin-O, on this material were evaluated through isothermal and kinetic modelling. The adsorption systems for both methylene blue and safranin-O can best be described using Langmuir isotherms and the respective adsorption capacities were 1.81 and 1.51 mg/g. The adsorption process was dominated by pseudo-second order rate kinetics. Comparisons are made with other mollusc-derived materials reported to date.

Light-Driven Site-Selective Glycosylation of Native Carbohydrates.

Carbohydrates constitute the largest source of biomass on Earth, but their synthetic modification is highly challenging due to their high content of oxygen functionalities. The site- and stereoselective modification of native sugars is a definitive goal of glycochemistry research. Recent efforts to bypass the need for protecting groups, leveraging selective activation through photochemical mechanisms for site-selective C-C bond formation from native sugars, are likely to largely impact all glycochemistry-related areas. Davis, Koh, and co-workers have recently presented their use of photocatalysis to develop a "cap and glycosylate" approach for the site- and stereoselective C-glycosylation of native sugars. The modernization of a direct radical functionalization of in situ formed thioglycoside using photocatalysis was used in the synthetic manipulation of unprotected carbohydrates. This allowed reaching complex saccharides, and post-translational modification of proteins.

Aqueous-based assembly of plant-derived proteins yields a crosslinker-free biodegradable bioplastic consistent with green chemistry principles.

Plastics are an indispensable part of modern life. Due to the harmful environmental consequences of petroleum-based plastic usage, there is an urgent need to replace them with biodegradable bioplastics that meet the sustainability standards required for a low environmental footprint. Here, we use plant-derived proteins to produce bioplastics. Since most plant-derived proteins are not water-soluble, there has always been a need to use acidic or basic solutions or organic solvents with plasticizers and crosslinkers to produce bioplastic. Here, we present a counterintuitive approach for using water-insoluble plant-derived soy and pea proteins to manufacture large-scale bioplastics using only water as a solvent without common plasticizers or crosslinkers. We show that bioplastics can form via a self-assembly process initiated by a small molecular initiator while maintaining favourable mechanical properties. The lack of crosslinking and the protein nature of the bioplastic leads to a rapid biodegradation process under various conditions. Overall, the approach we present is highly attractive in terms of cost and time, and most importantly, it obeys all the relevant principles of green chemistry in bioplastics production.

Microplastics in Cosmetics: Open Questions and Sustainable Opportunities.

The cosmetic industry is now changing or rather having an ecological transition in which formulations such as creams, lotions, and powders for make-up, skin and hair care must not contain microplastics, now a taboo word in this field. Nowadays, many companies are intensifying their research and development (R&D) work to align with recent and future legislation that provides for their elimination to safeguard the ecosystem. The production of new eco-sustainable materials is currently a hot topic which finds its place in a market worth above 350 billion dollars which will reach more than 700 billion dollars in a very short time. This review offers an overview of the main advantages and adverse issues relating to the use of microplastics in cosmetics and of their impact, providing an insight into the properties of the polymeric materials that are currently exploited to improve the sensorial characteristics of cosmetic products. In addition, the various regulatory restrictions in the different geographical areas of the world are also described, which is matter for reflection on future direction. Finally, a prospective vision of possible solutions to replace microplastics with sustainable alternatives complete the picture of the next generation personal care products to support decision-making in the cosmetic marketplace.

Eco-friendly hydrotropic spectrophotometric analysis of ranolazine hydrochloride.

Simple and eco-friendly biodegradable hydrotropes-assisted spectrophotometric experiments have been designed and validated to quantify ranolazine hydrochloride (RAN.HCl) in extended-release tablets. The citric acid and sodium citrate are employed as hydrotropes, serving as promising alternatives to polar organic solvents. The development of rapid and specific spectrophotometric experiments aimed at enhancing the spectral absorption of RAN.HCl. The spectrophotometric experiments are D0 and D0 AUC, in which the highest peak absorbance was observed at 270.50 nm, with an AUC ranging from 265.00 to 275.50 nm. Moreover, spectral analysis of D1 and D2 were conducted with peak amplitudes recorded at 280.00 nm and 274.40 nm, respectively. The AUC in the wavelength ranges 275.00-287.00 nm for D1, and 265.00-279.50 nm for D2 were implemented to quantify RAN.HCl confirms no interference from the common additives incorporated into the marketed preparation. The optimized experiments disclosed a linear relationship in the 0.02-0.16 mg/mL concentration range. The accuracy was performed at 50-150 %, revealing an overall average recovery of 100.02 %. The lowest limits of RAN.HCl that could be accurately detected and quantified were 0.0016 and 0.0049, 0.0018 and 0.0055, 0.0058 and 0.0176, 0.0024 and 0.0075, 0.0074 and 0.0224, 0.0021 and 0.0064 mg/mL, respectively, across these investigations. Statistical analysis revealed no significant differences between the outcomes of the present investigation and those documented in literature reports, based on the t- and F-values at p = 0.05, which were below the theoretical values of 2.2622, 2.3646, 6.26, and 19.20, respectively.

Recent Advances in Nanocatalyzed One-Pot Sustainable Synthesis of Bioactive N, N-Heterocycles with Anticancer Activities: An Outlook of Medicinal Chemistry.

N-heterocycles represent a predominant and unique class of organic chemistry. They have received a lot of attention due to their important chemical, biomedical, and industrial uses. Food and Drug Administration (FDA) approved about 75% of drugs containing N-based heterocycles, which are currently available in the market. N-Heterocyclic compounds exist as the backbone of numerous natural products and act as crucial intermediates for the construction of pharmaceuticals, veterinary items, and agrochemicals frequently. Among N-based heterocyclic compounds, bioactive N,N-heterocycles constitute a broad spectrum of applications in modern drug discovery and development processes. Cefozopran (antibiotic), omeprazole (antiulcer), enviradine (antiviral), liarozole (anticancer), etc., are important drugs containing N,N-heterocycles. The synthesis of N,Nheterocyclic compounds under sustainable conditions is one of the most active fields because of their significant physiological and biological properties as well as synthetic utility. Current research is demanding the development of greener, cheaper, and milder protocols for the synthesis of N,N-heterocyclic compounds to save mother nature by avoiding toxic metal catalysts, extensive application of energy, and the excessive use of hazardous materials. Nanocatalysts play a profound role in sustainable synthesis because of their larger surface area, tiny size, and minimum energy; they are eco-friendly and safe, and they provide higher yields with selectivity in comparison to conventional catalysts. It is increasingly demanding research to design and synthesize novel bioactive compounds that may help to combat cancer since the major causes of death worldwide are due to cancer. Hence, the important uses of nanocatalysts for the one-pot synthesis of biologically potent N,N-heterocycles with anticancer activities have been presented in this review.

Novel Graphitic Oxynitrides as Photocatalysts for Sustainable H2 Production and CO2 Valorization. The Importance of Self­Assembly for Catalytic Activity.

The field of carbocatalysis, often portrayed by paradigmatic graphitic carbonaceous structures, has become a booming topic tailored for multiple applications. To this end, a new metal-free carbocatalyst has been constructed from simple prebiotic monomers such as cyanamide and glyoxal. The resulting material shows an excellent performance as photocatalyst for H2 production and CO2 valorization, thus unveiling its real value to tackle sustainable goals. The unique oxygen-rich carbonaceous structure has been characterized in detail, which is consistent with a graphitic layered network. The described performance in two major societal concerns along with a facile preparation from C1/C2 platforms, makes this type of overlooked oxynitride carbocatalysts promising for real-life environmental endeavors.

Triplet-Sensitized Switching of High-Energy-Density Norbornadienes for Molecular Solar Thermal Energy Storage with Visible Light.

Norbornadiene-based photoswitches have emerged as promising candidates for harnessing and storing solar energy, holding great promise as a viable solution to meet the growing energy demands. Despite their potential, the effectiveness of their direct photochemical conversion into the resulting quadricyclanes has room for improvement owing to (i) moderate quantum yields, (ii) poor overlap with the solar spectrum and (iii) photochemical back reactions. Herein, we present an approach to enhance the performance of such molecular solar thermal energy storage (MOST) systems through the triplet-sensitized conversion of aryl-substituted norbornadienes. Our study combines deep spectroscopic analyses, irradiation experiments, and quantum mechanical calculations to elucidate the energy transfer mechanism and inherent advantages of the resulting MOST systems. We demonstrate remarkable quantum yields using readily available sensitizers under both LED and solar light irradiation, significantly surpassing those achieved through direct excitation with photons of higher energy. In contrast to the conventional approach, light-induced back reactions of the high-energy products do not play any role, allowing quantitative switching within minutes. These results not only underscore the potential of triplet-sensitized MOST systems to leverage the high energy storage capabilities of multistate photoswitches but they might also stimulate the broader usage of sensitization strategies in photochemical energy conversion.

In situ Generation of Cyclohexanone Drives Electrocatalytic Upgrading of Phenol to Nylon-6 Precursor.

Coupling in situ generated intermediates with other substrates/intermediates is a viable approach for diversifying product outcomes of catalytic reactions involving two or multiple reactants. Cyclohexanone oxime is a key precursor for caprolactam synthesis (the monomer of Nylon-6), yet its current production uses unsustainable carbon sources, noble metal catalysts, and harsh conditions. Herein, we report the first work to synthesize cyclohexanone oxime through electroreduction of phenol and hydroxylamine. The Faradaic efficiency reached 69.1 % over Cu catalyst, accompanied by a corresponding cyclohexanone oxime formation rate of 82.0 g h-1 gcat -1. In addition, the conversion of phenol was up to 97.5 %. In situ characterizations, control experiments, and theoretical calculations suggested the importance of balanced activation of water, phenol, and hydroxylamine substrates on the optimal metallic Cu catalyst for achieving high-performance cyclohexanone oxime synthesis. Besides, a tandem catalytic route for the upgrading of lignin to caprolactam has been successfully developed through the integration of thermal catalysis, electrocatalysis, and Beckmann rearrangement, which achieved the synthesis of 0.40 g of caprolactam from 4.0 g of lignin raw material.

Aldehyde End-Capped Degradable Polyethylenes from Hydrogen-Controlled Ethylene/CO Copolymerization.

To access degradable polyolefin plastic, non-alternating copolymerization of ethylene (E) and carbon monoxide (CO) for producing polyethylene (PE) with in-chain ketones is particularly appealing; however, it still presents significant challenges such as molecular weight modulation (hydrogen response) and chain endgroup control (functional terminal). In this study, we achieved hydrogen-controlled E/CO non-alternating copolymerization using late transition metal catalysts. This process results in linear PEs containing the desired non-alternating in-chain keto groups (1.0-9.3 mol%) and with tunable molecular weights ranging from 43 to 195 kDa. In this reaction, H2 serves as a chain transfer agent, modulating the polymer's molecular weight, forming unique aldehyde endgroups and eliminating usual olefinic endgroups; CO undergoes non-alternating insertion into the PE chain, resulting in a strictly non-alternating structure (> 99%) for the keto-PE. The dispersed incorporation of in-chain keto groups retains bulk properties of PE and makes PE susceptible to photodegradation, which produces significantly lower molecular weight polymers and oligomers with unambiguous vinyl and acetyl terminals.

Synthesis of 4-(Phenylamino)quinazoline-2(1H)-thiones Using Green Solvents.

Given the importance of quinazolines and quinazolinethiones in therapeutic and Food and Drug Administration (FDA)-approved molecules, we thought interesting to consider their synthesis in green solvents. We have shown that obtain 4-(arylamino)quinazoline-2-(1H)-thiones and 4-(arylamino)pteridine-2-(1H)-thiones analogues was efficient in green solvents derived from biomass, especially eucalyptol. Although reaction times are somewhat long to achieve good yields, the products were obtained by simple filtration. This considerably limited the loss of atoms due to the use of large quantities of solvents for purification on silica gel columns, and makes our route a sustainable one.

Glycerol as Reaction Medium for Sonogashira Couplings: A Green Approach for the Synthesis of New Triarylamine-Based Materials with Potential Application in Optoelectronics.

This study focuses on the design, eco-friendly synthesis, and characterization of several novel three-legged triphenylamine derivatives. By performing Sonogashira couplings of functionalized aryl iodides with tris(4-ethynylphenyl)amine in glycerol, a readily available bio-derived solvent, we achieved the synthesis of target products in short times and high yields, up to 94%, with consistently lower E-factors and reduced costs compared to standard conditions using toluene as the reaction medium. The target molecules possess a D-(π-A)3 or D-(π-D)3 structure, where an electron-donating core connects to three electron-donating (D) or electron-accepting (A) peripheral aromatic subunits through an acetylene spacer. Their main optical and electronic properties have been determined experimentally and by DFT simulations and suggest a possible implementation in energy conversion technologies such as luminescent solar concentrators (LSCs) and perovskite solar cells (PSCs).

High-Energy Ball Milling Enables an Ultra-fast Wittig Olefination Under Ambient and Solvent-free Conditions.

30 Seconds to success! - The Wittig reaction, a fundamental and extensively utilized reaction in organic chemistry, enables the efficient conversion of carbonyl compounds to olefins using phosphonium salts. Traditionally, meticulous reaction setup, including the pre-formation of a reactive ylide species via deprotonation of a phosphonium salt, is crucial for achieving high-yielding reactions under classical solution-based conditions. In this report, we present an unprecedented protocol for an ultra-fast mechanically induced Wittig reaction under solvent-free and ambient conditions, often eliminating the need for tedious ylide pre-formation under strict air and moisture exclusion. A range of aldehydes and ketones were reacted with diverse phosphonium salts under high-energy ball milling conditions, frequently giving access to the respective olefins in only 30 seconds.

Turning Solid Waste into Catalysts: A Path for Environmental Solutions.

Waste, often overlooked, stands out as a prime source of valuable products, meeting the demand for natural resources. In the face of environmental challenges, this study explores the crucial role of waste-derived catalysts in sustainable practices, emphasizing the transformative potential of solid waste materials. Carbon-based catalysts sourced from agricultural, municipal, and industrial waste streams can be transformed into activated carbon, biochar, and hydrochar which are extensively used adsorbents. Furthermore, the paper also highlights the potential of transition metal-based catalysts derived from spent batteries, electronic waste, and industrial byproducts, showcasing their efficacy in environmental remediation processes. Calcium-based catalysts originating from food waste, including seashells, eggshells, bones, as well as industrial and construction waste also find an extensive application in biodiesel production, providing a comprehensive overview of their promising role in sustainable and eco-friendly practices. From mitigating pollutants to recovering valuable resources, waste-derived catalysts exhibit a versatile role in addressing waste management challenges and promoting resource sustainability. By transforming waste into valuable catalysts, this study champions a paradigm shift towards a more sustainable and resource-efficient future.

Enhancing Efficiency of Nitrate Reduction to Ammonia by Fe and Co Nanoparticle-Based Bimetallic Electrocatalyst.

The green and sustainable electrocatalytic conversion of nitrogen-containing compounds to ammonia is currently in high demand in order to replace the eco-unfriendly Haber-Bosch process. Model catalysts for the nitrate reduction reaction were obtained by electrodeposition of metal Co, Fe, and bimetallic Fe/Co nanoparticles from aqueous solutions onto a graphite substrate. The samples were characterized by the following methods: SEM, XRD, XPS, UV-vis spectroscopy, cyclic (and linear) voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. In addition, the determination of the electrochemically active surface was also performed for all electrocatalysts. The best electrocatalyst was a sample containing Fe-nanoparticles on the layer of Co-nanoparticles, which showed a Faradaic efficiency of 58.2% (E = -0.785 V vs. RHE) at an ammonia yield rate of 14.6 µmol h-1 cm-2 (at ambient condition). An opinion was expressed to elucidate the mechanism of coordinated electrocatalytic action of a bimetallic electrocatalyst. This work can serve primarily as a starting point for future investigations on electrocatalytic conversion reactions to ammonia using model catalysts of the proposed type.

NCCR Catalysis at a Glance: A National Research Program on Sustainable Chemistry.

Curious about how chemistry can contribute to sustainable development? In this overview, we explain the essence of NCCR funding, the research focus and structural goals of NCCR Catalysis, and how these align with the sustainable development goals (SDGs). Additionally, we highlight opportunities for getting involved with our program.

Switchable Deep Eutectic Solvents for Sustainable Sulfonamide Synthesis.

A sustainable and scalable protocol for synthesizing variously functionalized sulfonamides, from amines and sulfonyl chlorides, has been developed using environmentally responsible and reusable choline chloride (ChCl)-based deep eutectic solvents (DESs). In ChCl/glycerol (1 : 2 mol mol-1) and ChCl/urea (1 : 2 mol mol-1), these reactions yield up to 97 % under aerobic conditions at ambient temperature within 2-12 h. The practicality of the method is exemplified by the sustainable synthesis of an FFA4 agonist and a key building block en route to anti-Alzheimer drug BMS-299897. A subtle interplay of electronic effects and the solubility characteristics of the starting materials in the aforementioned DESs seem to be responsible for driving the reaction successfully over the hydrolysis of sulfonyl chlorides. The procedure's eco-friendliness is validated by quantitative metrics like the E-factor and the EcoScale, with products isolated by extraction or filtration after decantation.

Retrieval and reuse of surfactants from microemulsions enabled by a pH-triggered precipitation-dissolution strategy.

How to retrieve and reuse surfactants efficiently from surfactant-based microemulsions (MEs) has long been a problem, which is full of challenges and needs to be solved urgently. To this end, a pH-triggered precipitation-dissolution (PTPD) strategy is developed. The surfactant sodium 3-(laurylamino)propane-1-sulfonate (LMPS) transforms into an insoluble precipitate (the inner salt of LMPS, LMP) after reaction with HCl, by which the monophasic LMPS-based MEs demulsified entirely, giving a separable mixture of oil, water and LMP. LMP can be retrieved efficiently (~95.3%) regardless of the ME type, and can then be conveniently restored to LMPS via reactions with NaOH. Conceptually, the retrieval of LMPS (~96.6%), toxic benzo[a]pyrene (BaP, ~99.5%) and a mixture of co-surfactant n-butanol and the oil phase n-heptane (~97.1%) from the sufficiently emulsified soil eluents is achievable by respectively using the PTPD strategy and distillation, wherein the soil eluents were generated from the remediation of BaP-contaminated soil using an oil-in-water LMPS-based ME as washing agent. It reveals a promising future for the PTPD strategy in the post-processing of soil eluents containing toxic hydrophobic organic contaminants and excessive surfactants.

Towards a Sustainable Future: Challenges and Opportunities for Early-Career Chemists.

The concepts of sustainability and sustainable chemistry have attracted increasing attention in recent years, being of great importance to the younger generation. In this Viewpoint Article, we share how early-career chemists can contribute to the sustainable transformation of their discipline. We identify ways in which they can engage to catalyse action for change. This article does not attempt to answer questions about the most promising or pressing areas driving research and chemical innovation in the context of sustainability. Instead, we want to inspire and engage early-career chemists in pursuing sustainable actions by showcasing opportunities in education, outreach and policymaking, research culture and publishing, while highlighting existing challenges and the complexity of the topic. We want to empower early-career chemists by providing resources and ideas for engagement for a sustainable future globally. While the article focuses on students and early-career chemists, it provides insights to further stimulate the engagement of scientists from diverse backgrounds.

Heterogeneous Iron-Based Catalysts for Organic Transformation Reactions: A Brief Overview.

Iron (Fe) is considered to be one of the most significant elements due to its wide applications. Recent years have witnessed a burgeoning interest in Fe catalysis as a sustainable and cost-effective alternative to noble metal catalysis in organic synthesis. The abundance and low toxicity of Fe, coupled with its competitive reactivity and selectivity, underscore its appeal for sustainable synthesis. A lot of catalytic reactions have been performed using heterogeneous catalysts of Fe oxide hybridized with support systems like aluminosilicates, clays, carbonized materials, metal oxides or polymeric matrices. This review provides a comprehensive overview of the latest advancements in Fe-catalyzed organic transformation reactions. Highlighted areas include cross-coupling reactions, C-H activation, asymmetric catalysis, and cascade processes, showcasing the versatility of Fe across a spectrum of synthetic methodologies. Emphasis is placed on mechanistic insights, elucidating the underlying principles governing iron-catalyzed reactions. Challenges and opportunities in the field are discussed, providing a roadmap for future research endeavors. Overall, this review illuminates the transformative potential of Fe catalysis in driving innovation and sustainability in organic chemistry, with implications for drug discovery, materials science, and beyond.