Current Green Chemistry - Volume 12, Issue 4, 2025

Heterocycles are of much importance as the majority of the existing drugs contain one or more heterocyclic units in their structures. Among all the heterocycles, nitrogen, and sulphur-containing ones occupy major space, and they have special properties which make them suitable for the textile, cosmetic, and paint industries other than pharmaceutical. Recently, visible light has emerged as a powerful tool for performing various reactions at ambient temperatures and mild conditions and thus it has been used for the key step in the synthesis of many molecules. In addition, visible light assisted methods are usually cost and time effective. Thus, this review highlighted the recent developments in visible light induced methods for the synthesis of some selected biologically active N- and S- containing heterocycles such as benzothiazoles, indoles and triazoles and their functionalization. The advantages, green aspects and limitations of these methods have also been discussed.

In recent years, the pursuit of sustainable and efficient methods for organic synthesis has gained significant momentum. Among the emerging strategies, vacuum-assisted organic synthesis is a promising approach, offering the potential to expedite reactions, boost yields, and minimize waste generation. This review delves into the innovative utilization of rotary evaporators as a reactor for vacuum-assisted organic synthesis, showcasing their unique advantages and potential. The advantages of this approach and the recent examples of vacuum-accelerated reactions carried out in rotary evaporators are discussed, demonstrating their versatility and potential for green catalysis. By exploring the untapped potential of rotary evaporators as reactors, we aim to stimulate further research in this burgeoning field and contribute to the ongoing endeavour to transform organic synthesis into a more sustainable and efficient practice.

Clean and safe drinking water is one of the most important basic needs of human beings. The modern lifestyle and vast industrial evolution caused freshwater pollution. To purify and supply clean water, research on wastewater treatment is a high priority. Various types of carbon materials such as activated carbon, mesoporous carbon, carbon nanotubes, graphene and graphene oxide materials are widely elaborated as the adsorbents for the purification of the water. The activated carbon-based nanostructures are ideal for this goal. These materials are highly capable of adsorbing the poisonous heavy metals and organic dyes from the wastewater. Herein, we have summarized the last six-year total of thirty literature reports focusing on the applications of biowaste-based activated carbon nanomaterials in the field of water and wastewater treatment. We strongly believe that this review will help the new researchers in this field to get detailed insights into the recent advances in biowaste-based activated carbon nanomaterials for water treatment.

Biological evolution has omitted organic silicon from the Earth's scab, which forms approximately 28% of the Earth's crust. However, there is a growing interest in organosilicon compounds due to their widespread use in organic synthesis, material science, agrochemistry, and medical research. Recently, there have been many applications of silicon-stereogenic organosilanes in syntheses, medicinal chemistry, and functional materials, making them an important topic for research. However, in silicon, it is possible for the stereogenic center to be racemized as it can form more than four covalent bonds. By overcoming this issue, transition-metal-catalyzed transformations have achieved significant progress in the synthesis of silicon-stereogenic silanes over the last decade. However, transition metal-free approaches are quite challenging with respect to the stability of the chiral centers. This study will comprehensively summarize the advances in the transition-metal-free asymmetric synthesis of chiral silicon-containing molecules. The mild reaction conditions and environmentally friendly reagents that are used in these organocatalytic methods make the process significant for the advancement of green chemistry.

Heterocyclic chemistry is an essential area of study in organic chemistry, especially due to the biological and pharmacological importance of heterocyclic compounds. Developing sustainable, heterogeneous catalysts for the efficient, eco-friendly synthesis of pyrano[2,3-c]pyrazole scaffolds is a key objective in modern synthesis. These N/O-containing fused five-six membered rings have unique structures and bioactivities that make them promising candidates for use in antimicrobial and anticancer drug development. This review explores the role of heterogeneous catalysis in synthesizing bio-active pyrano[2,3-c]pyrazoles through one-pot, cyclocondensation, and multi-component reactions, emphasizing their significance in drug development.

Paracetamol is one of the most prescribed drugs, which requires a global production of over 200,000 tons/year. The production of paracetamol at the industrial level still relies on multistep methodologies utilizing stoichiometric amounts of oxidizing and reducing agents and corrosive reagents, which demands a sustainable protocol for the synthesis of paracetamol. In this article, we aimed to develop a magnetically retrievable nanohybrid catalyst for the synthesis of paracetamol under mild and green reaction conditions for up to five cycles. Fe3O4 nanoparticles were synthesized and Pd(0) particles were embedded into the nanoparticle so that it could be used as a magnetically retrievable catalyst. This hybrid catalyst was successfully utilized in the synthesis of paracetamol in a one-pot reaction with high yield and efficacy within a short time, demonstrating that the nanohybrid catalyst offers advantages in the synthesis of drug leads for industrial purposes.

In the modern era, petrochemical industries' production of hydrocarbon pollution is a significant environmental problem that causes biodiversity loss. Alkanes constitute a substantial proportion of crude oil, and refined fuels are found in small amounts in various uncontaminated environments. They are prevalent in underground fossil fuel reserves and shallow subsurface habitats polluted with hydrocarbons, such as aquifers. Using microorganisms to break down alkane hydrocarbon pollutants in environmental areas has great potential. Considerable advancements have been achieved in identifying microorganisms and metabolic processes responsible for the breakdown of alkanes in both oxygen-free and oxygen-rich conditions in the last two decades. A wide range of prokaryotic and eukaryotic organisms have been identified and observed to possess the ability to utilize various carbon and energy sources as substrates. Bioremediation is essential for environmental safety and management; various methods have been established for petroleum hydrocarbon bioremediation. Numerous microbial species have been employed to investigate the bioremediation of petroleum hydrocarbons, highlighting the crucial functions of varied microbial communities. Phytoremediation is an environmentally sustainable method that may effectively rehabilitate heavy metal-contaminated soil cost-efficiently. This manuscript provides an overview of prevalent alkane hydrocarbon pollutants, microorganisms capable of degrading hydrocarbons, key pathways and enzymes involved in hydrocarbon degradation, factors influencing hydrocarbon degradation, and various strategies employed to harness the degrading capabilities of microbes for remedial purposes.

Developing sustainable biodiesel production relies on investigating local microalgal populations to detect neutral lipid accumulation via high throughput screening. This study evaluates the efficacy of using various isolation strategies for maximizing microalgal strain collection from low-abundance water samples. The study resulted in the isolation of twenty-five algal strains, of which 3 oleaginous strains were identified as Chlorococcum aquaticum BB607, Chlorococcum sp. BB601 and Spongiosarcinopsis limneus BG607 were selected. Isolate C. aquaticum BB607 exhibited substantial lipid content of 456.45 ± 2.40 µg/mL, lipid productivity of 38.04 ± 0.20 µg/mL/day, biomass yield of 4.23 ± 0.06 mg/mL and maximum percentage C16-C18 fatty acid profile compared to the other two isolates. Further, the FAMEs produced from this isolate exhibited high CN (60.384), low iodine value (97.33 g I2/100 g) and negative cold filter plugging point (-2.28°C). This demonstrates the potential of C. aquaticum strain BB607 as a feedstock biodiesel production.