An efficient micellar palladium-catalyzed aqueous Buchwald-Hartwig amination has been developed, enabled by the self-assembly of amphiphilic copolymer polyethylene glycol-polyvinylethylene glycol (PEG-PVEG). Using 0.5 mol % BrettPhos-Pd-G3 as a catalyst, the aqueous amination showed broad a substrate scope, including aryl bromides, aryl chlorides, sterically hindered reaction partners, and amides. The practical utility of this micellar system was demonstrated by the gram-scale synthesis of a key pharmaceutical API intermediate and catalyst recycling.

Atomically thin high-entropy hydroxides (HEHs) hold great promise for energy and environmental catalysis, yet their controlled synthesis is hindered by two key challenges: (i) thermodynamic incompatibility in multication coprecipitation and (ii) limited thickness control during layered crystallization. Here, this study describes an approach to overcome these obstacles using a dissolution-mediated growth strategy based on the precise regulation of metal cation flux. Our approach leverages the ultrafast NaBH4-driven coreduction of mixed metal precursors, yielding metastable high-entropy boride (HEB) intermediates. Subsequent atmospheric oxidation gradually destabilizes the HEB lattice, facilitating the diffusion-controlled release of metal cations, which react in situ with hydroxide ions generated by NaBH4 hydrolysis to form atomically thin HEHs. The high-entropy effect endows the resulting HEHs with a defect-rich atomic architecture, rendering them efficient catalysts for polyester waste recycling. The FeCoNiCuZn-HEH-derived high-entropy metal oxides achieve 100% glycolytic recycling of poly(ethylene terephthalate) (PET), a performance not matched by their low-entropy and medium-entropy counterparts synthesized via the same strategy. The versatile and highly effective synthesis approach presented here not only advances the fabrication of high-entropy materials but also underscores their significant potential for sustainable polymer upcycling.

ABSTRACT Carbon nano‐onions (CNOs) are efficiently functionalized using a sustainable approach based on polymerizable deep eutectic solvents (PDESs), or deep eutectic monomers (DEMs). These systems replace conventional organic solvents, acting simultaneously as dispersing media and functionalization reagents. The method enables the rapid introduction of functional groups such as –OH, –NH 3 ⁺Br − , and –SO 3 − onto CNO surfaces. The resulting materials are comprehensively characterized by TGA, 13 C‐CPMAS‐TOSS NMR, FT‐IR spectroscopy, TEM, AFM, DLS, and XPS. Notably, sulfonate‐functionalized CNOs support the Keggin‐type polyoxometalate H 3 PW 12 O 40 (PW 12 ), which acts as a recyclable heterogeneous catalyst for the oxidation of alcohols to carbonyl compounds.

Amide formation through the Ritter reaction remains a valuable transformation in pharmaceutical and materials chemistry, yet conventional protocols rely heavily on corrosive homogeneous acids and non-green conditions. In this study, a magnetite nanoparticles/graphitic carbon nitride/ nitrilotri(methylphosphonic acid (Fe3O4/g-C3N4/NTMPA) magnetic nanocomposite (MNC) was synthesized via a co-precipitation method and employed as an efficient and recyclable solid acid catalyst for solvent-free Ritter reactions at 80°C. Structural and morphological analyses using FT-IR, XRD, FE-SEM, TEM, DLS, and EDX confirmed successful incorporation of NTMPA and uniform distribution of Fe, C, N, O, and P throughout the composite. BET analysis showed a surface area of 11.421m2/g, pore volume of 0.0588cm³/g, and mean pore diameter of 20.593nm, indicating a mesoporous structure conducive to catalytic accessibility. TGA revealed a major decomposition step of 23.88% between 500 and 600°C corresponding to g-C3N4 degradation, confirming appropriate thermal stability. The catalyst demonstrated broad substrate applicability, converting tertiary alcohols and benzylic alcohols to the corresponding amides in high to excellent yields in 1.25-6h. Aromatic nitriles consistently delivered yields above 90% within 5-6h, with electron-withdrawing substituents further enhancing reactivity and aliphatic nitriles provide the related amides in 87-98% yields within 1.5-5.5h. The catalyst retained over 90% activity after six cycles, with post-reaction analyses confirming structural integrity. These results highlight Fe3O4/g-C3N4/NTMPA as a robust, magnetically recoverable, and environmentally compatible catalyst for green amide synthesis.

A novel two-dimensional cobalt(II)-based metal-organic framework (Co-MOF) was synthesized using combined solvothermal and sonochemical methods. The structure of the compound, [Co(HL)(bipy)(H2O)]n (H3L = m-(phosphonomethyl)benzoic acid), was determined by single-crystal X-ray diffraction and confirmed to form a two-dimensional coordination polymer. The nanostructured form (Co-MOF') was obtained via ultrasonic irradiation and comprehensively characterized by FT-IR, PXRD, SEM, EDX, TGA, and BET techniques. The Co-MOF' exhibited excellent catalytic performance in the one-pot synthesis of 3,4-dihydropyrimidinones (DHPMs) via the Biginelli reaction under green, solvent-free conditions. The catalyst offered high product yields (up to 97%) within short reaction times (30 min), remarkable recyclability over seven cycles without significant loss of activity, and superior performance compared to previously reported MOF-based catalysts. This study highlights the potential of Co-MOF' as an efficient, reusable, and environmentally benign heterogeneous catalyst for multicomponent organic transformations.

Recyclable Hydrotalcite-Supported Copper Catalysts for Green and Regioselective Click Synthesis of 1,2,3-Triazoles

Enhanced solar light photo-Fenton degradation of refractory organics using algae-derived CQDs modified magnetic α-Fe2O3: Novel synthesis, mechanism insight, and phytotoxicity assessment.

Organoboron compounds are important intermediates in contemporary organic synthesis, but their radical synthetic strategy remains challenging due to their inherent instability. Polyoxometalate clusters (POMs) have emerged as an important class of catalysts because of their multiple active sites, high stability, and catalytic activity. Herein, we report a Keggin polyoxometalate (PMo12O403-) cluster for the radical hydroboration of alkynes and alkenes. Mechanistic studies show that an intervalence charge transfer transition (IVCT) from MoV to MoVI enables the generation of boryl-centered radicals under mild conditions. This work demonstrates the phosphomolybdate clusters featuring unique multiple Mo sites and strong electron reservoir properties, which promotes efficient C-B bond forming reactions. The catalyst is compatible with a variety of alkynes and alkenes and functional groups for delivering hydroborated products in green solvents. Moreover, the application of this method is also showcased by the gram-scale synthesis, catalyst recycling, and further modifications of the product.

The “aldehyde-water shift” (AWS) reaction offers a green and sustainable route for producing carboxylic acids with the concomitant release of hydrogen. However, most current AWS processes rely on homogeneous noble metal-based catalysts, facing significant challenges in the separation and recyclability of catalysts. Herein, we present the Pt nanoparticles deposited on highly defective porous CeO2 nanorods (Pt/PN-CeO2) as highly effective catalysts for the production of carboxylic acids and H2 through the AWS reaction. Isotope investigations have confirmed the occurrence of AWS by tracing the origin of the generated hydrogen with one hydrogen from aldehyde and one hydrogen from water. Further mechanism studies have illustrated that the concentration of oxygen vacancies plays a crucial role in both the activation of the C–H bond in aldehydes and the activation of water. These findings provide valuable insights for designing new catalytic systems by focusing on the construction of heterogeneous catalysts for the AWS reaction.

Biodiesel is popular as an eco-friendly fossil fuel alternative. Neem oil is manufactured from Azadirachta indica seeds. Transesterifying triglycerides with alcohol in the presence of a synthesized CaO nanocatalyst is the most common biodiesel synthesis procedure-recent advances, difficulties, and prospects in laser feedstock pretreatment to boost reactivity and reduce energy use. Oil pre-treatment with a 540-nm green laser is cost-effective and environmentally friendly. This study examined neem oil with and without laser pretreatment for biodiesel synthesis. CaO nanocatalysts were synthesised using Sol-gel and characterised using XRD and SEM. According to catalyst recyclability, the CaO nanocatalyst did not lose activity after five reuses. The CaO nanocatalyst retained 97.7% of its initial activity after five reuses, as confirmed by the small decrease in biodiesel synthesis from 97% to 94.8%. The study went through the optimization of batch-based biodiesel production named as Laser Neem Oil Methyl Ester's (LNOME's) at various process parameters such as reaction temperature (40-70°C), reaction time (60-150min), catalyst weight percentage (0.5-1.25 wt%), and methanol-to-oil molar ratio (10-25). Neem oil biodiesel performed best at 50°C. After 90min, both feedstocks achieve their maximum FAME conversion rate. The ideal conversion ratio for neem oil biodiesel to methanol was found to be 1:20. Because this process is reversible, the amount of biodiesel converted increases according to the amount of methanol utilized. The neem oil produced 97% Biodiesel when a laser was used, and 94% when it wasn't. Laser processing and sol-gel nanocatalysts are also showcased in this novel work. Combining the efficiency of nanocatalytic processing with environmentally friendly processing methods, this method brings a double breakthrough to the field of reaction chemistry. Due to their reduced reaction time and better yield (97%). Furthermore, the characterization of both the feedstocks and the synthesized biodiesel was determined by using GC-MS, FTIR, and H-NMR. Laser pretreatment shows promising enhancement of conversion efficiency and reduced reaction time, potentially leading to higher-quality biodiesel.

Highly efficient hydrosilylation of alkenes using a recyclable ZnO nanoparticle catalyst under ligand-free conditions

This study presents a novel, sustainable catalytic system for the Biginelli reaction, utilizing a sulfonated carbon catalyst synthesized from underutilized corn cob waste via ZnCl2 activation and dual step sulfonation. The resulting catalyst, 2S2Zn-500, exhibited high surface area (739m2/g), good acidity (0.48mmol/g SO3H), and well-defined mesoporosity, enabling efficient multicomponent synthesis of dihydropyrimidinones (DHPMs) under mild conditions (95°C, 5h) in biodegradable palm oil, a green solvent alternative. This catalyst delivered high yields up to 91% and demonstrated good reusability over five cycles with minimal loss in activity. Comprehensive characterization (XRD, FTIR, SEM-EDS, XPS, Raman, TEM, BET, TGA) confirmed its structural integrity, functional group incorporation, and thermal stability. The system achieved impressive green metrics (Atom Economy: 86-93%; E-factor: 21-32; PMI: 22-33), outperforming several literature-reported biomass-derived catalysts in terms of sustainability, efficiency, and operational simplicity. This is the first report of a ZnCl2-activated, sulfonated corn cob catalyst used in tandem with palm oil for Biginelli synthesis, offering a cost-effective, metal-free, and circular approach to biomass valorization. The integration of a renewable feedstock, recyclable catalyst, and eco-friendly solvent positions this work as a compelling model for green multicomponent synthesis and bio-waste utilization.

A visible-light-driven direct C-H alkylation of heterocycles using Cu@g-C3N4 heterojunctions as recyclable photocatalysts and alkylhydrazines as alkylating reagents was reported. This heterogeneous photocatalytic system can operate under additive-free and mild conditions to deliver an assortment of alkylated heterocycles in moderate to excellent yields, featuring high efficiency, broad substrate scope, easy scalability, excellent functional group tolerance, and exceptional catalyst recyclability.

Covalent organic frameworks (COFs) incorporating photoredox-active motifs show great promise as heterogeneous catalysts, yet their applications have been largely confined to one-step transformations. In this work, we design and synthesize a series of three-dimensional (3D) COFs with different π-extended dihydrophenazine cores to achieve superior photocatalytic performance. These 3D COFs exhibit excellent crystallinity, high surface areas, and remarkable chemical stability. More importantly, they can work as highly efficient and recyclable catalysts for photocatalytic tandem polymerization reactions using styrene and fluoroalkyl anhydrides as substrates, yielding fluoroalkylated polystyrene polymers with narrow dispersity. These COFs constitute the first examples as tandem photocatalysts toward polymerization reactions. Moreover, optimal energy level alignment and enhanced photophysical properties are identified as key factors contributing to their high efficacy. This work not only provides a viable design strategy for multifunctional COF catalysts, but also expands their utility in complex synthetic sequences involving tandem catalytic processes.

ABSTRACT An eco‐friendly, visible‐light‐driven synthesis of benzamides from readily accessible benzonitriles is reported under heterogeneous conditions. A carbon‐rich material, such as polyhexahydrotriazine (PHT), graphene oxide (GO), graphitic nitride (g‐C 3 N 4 )or carbon black, was used as a novel support to stabilise silver nanoparticles (NPs). These silver NPs show remarkable catalytic activity in the hydration of nitriles under visible light irradiation (white light, 9 W). Furthermore, silver NPs stabilised by a triazine moiety exhibit better performance than other supported silver systems, including graphene oxide and carbon black. Their stability and heterogeneous nature as catalysts have been demonstrated through three cycles of recycling in the synthesis of benzamides. This approach utilises mild visible light and a recyclable catalyst that efficiently converts benzonitriles to amides in excellent yields. This work provides a sustainable approach to amide synthesis. Density functional theory (DFT) calculations further indicate that the binding energy of 4‐bromobenzonitrile (BCN) to Ag@C 3 N 4 is −31.50 kcal/mol. Further triphenyl phosphine poisoning test confirms the heterogeneous nature of our catalyst under visible light.

A water-soluble imidazolium-functionalized Cu(ii) catalyst, used in combination with tert-butyl hydroperoxide (TBHP), enables benzylic and allylic oxidations in H2O. The reaction proceeds under green conditions, open to air, at moderate temperatures, yielding moderate to high conversion across a broad range of substrates. The catalyst is easily recovered and can be used in subsequent reactions up to 8 times without a significant decrease in yield.

A one-pot method was developed for synthesizing pyrazolo[4′,3′:5,6]pyrido[2,3-d]pyrimidin-5-ones using the recyclable ionic liquid catalyst [BMIM]OAc in ethanol under reflux conditions. This approach achieved high yields (76–95%) across various substrates along with straightforward product isolation and catalyst recyclability. The synthesized compounds 4(a–l) were tested for antimicrobial activity against Gram-positive and Gram-negative bacteria, and fungal strains. Notably, compounds 4c and 4e showed strong antibacterial effects against S. aureus (MIC: 8 µg mL−1), while 4a, 4b, and 4f effectively inhibited E. coli (MIC: 8 µg mL−1). Compound 4l exhibited notable antifungal activity against C. albicans (MIC: 8 µg mL−1), outperforming the standard drugs. Cytotoxicity assessment on HEK293 cells revealed low toxicity in most derivatives (IC50 > 50 µM), with halogenated analogs (4c, 4e) displaying moderate activity but remaining less toxic than doxorubicin. Molecular docking and dynamics simulations confirmed stable interactions of key compounds (4c, 4e, 4f) with bacterial Tet repressor class D and fungal sterol 14-α demethylase, consistent with experimental data. Overall, this ionic liquid-catalyzed approach provides an efficient route to bioactive heterocycles with promising antimicrobial and anticancer potential.

Here, we demonstrate NiCo2O4 nanoparticle-catalyzed dehydrogenative esterification and amidation of primary alcohols to esters of fatty acids and amides under microwave irradiation, without the need for any oxidant, achieving excellent yields of esters (50–92%) and amides (72–80%). The NiCo2O4 nanomaterial was prepared through co-precipitation, and its composition, morphology, structure, and textural properties were analyzed via powder XRD, FESEM, EDX, TEM, and BET. The crystallite size was found to be 121.69 nm using the Scherrer equation, by considering the FWHM of the (311) diffraction plane. The FESEM and EDS analysis revealed the formation of spherical-shaped granules with a mean size of 0.251 µm and their elemental composition. Furthermore, HRTEM images with a mean size of 2.25 nm confirmed the formation of spherical NiCo2O4 nanoparticles. The mesoporous nature of the material is analyzed by the BET surface area (33.81 m2 g−1) and average pore diameter 23.49 nm. The NiCo2O4 nanoparticles remained stable throughout the reaction process and were reusable for up to eight cycles. The catalytic nature of NiCo2O4 has been proved by cyclic voltametric studies of fresh and recycled catalysts. The present dehydrogenative esterification and amidation protocol offers several advantages, for example, robust and recyclable NiCo2O4 nanoparticles as a catalyst, oxidant- and solvent-free reaction conditions, microwave-assisted faster reaction rate, excellent isolated yields of products, etc.

Crosslinked bis(triphenylphosphine)iminium chlorides are recyclable catalysts for small molecule CO 2 and CO insertions and polymerisations.

ABSTRACT An eco‐friendly, metal‐free C‐7 amination of pyrazolo[1,5‐ a ]pyrimidines has been achieved in aqueous media under ultrasound irradiation. A variety of 7‐amino pyrazolo[1,5‐ a ]pyrimidines was prepared by employing this operationally simple method in good yield. The methodology involved reaction of 7‐chloro pyrazolo[1,5‐ a ]pyrimidines with amines using β‐cyclodexrin as a recyclable catalyst. The in silico docking of synthesized compounds into tumor necrosis factor‐α (TNF‐α) suggested TYR135, TYR227, ILE231, LEU133, LEU233, and LEU196 as the common interacting residues of TNF‐α trimer, whereas compounds 3a, 3b, 3d , and 3e showed superior binding affinities with the order 3d > 3a > 3b > 3e . Apart from H‐bonding with B: TYR195, the compound 3d participated in additional H‐bond interactions with B: GLY198 and B: ILE134 through its fluoro group that contributed to its higher binding affinity. Correlating the outcome of in silico studies, the in vitro assay results identified 3a , 3b , and 3d as initial hits with IC 50 in the range of ∼6.1–6.9 µM that were better than known inhibitor thalidomide (but not rolipram). The structure–activity relationship (SAR) analysis within the current series indicated that the 7‐amino aryl moiety played a key role in the observed TNF‐α inhibitory activities. All these studies indicated medicinal value of hits identified and that 3d could be of further interest.