Heteroatom Research Articles

Switching of newly synthesized linker-based derivatives of non-steroidal anti-inflammatory drugs toward anti-inflammatory and anticancer activity

A new series of linker-based derivatives of non-steroidal anti-inflammatory drugs were designed and synthesized. All the compounds were well characterized with the help of various spectroscopic techniques such as FT-IR, 1H NMR, 13C NMR, and HRMS. The main emphasis of this paper is to understand the switching of the most promising compounds 8 and 10 towards anti-inflammatory and anticancer activity in terms of in-silico and in-vitro studies in detail. During the molecular docking study, compounds 8 and 10 demonstrated the importance of hetero atoms as well as the perfect alignment of a compound in the binding pocket of a target site, which may affect their bioactivity. Here, the presence of 1,3‑dicarbonyl interactions with ASN 351 in compound 8 (not found in compound 10) may be responsible for its better inhibitory activity against the COX-2 target site. On the other hand, a slight increase in the potency of compound 10 towards anticancer activity may be due to the instantaneous participation of the OH group and carbonyl group to give conventional hydrogen bonds towards THR 149 amino acid residue, which was missing in compound 8. Molecular dynamics simulation was also performed for compounds 10 and 8 toward COX-2 and HER-2 protein sites. Further, compounds 8 and 10 were subjected to in-vitro COX-2 inhibition and cytotoxicity assay and the results obtained were in accordance with the in-silico study. Thus, compound 8 become more potent towards COX-2 inhibition with IC50 value of 48.51 µg/ml and compound 10 showed good bioactivity toward cytotoxic activity with IC50 value of 93.03 µg/ml.

Accuracy of Intermolecular interaction Energies, Particularly Those of Hetero Atom Containing Molecules Obtained by van der Waals DFT Calculations

AbstractThe performance of 24 vdW‐DF functionals were evaluated. The calculated intermolecular interaction potentials for 11 complexes, which conatain O, S, Se, N, P, F, Cl and Br atoms, were compared with CCSD(T)/CBS level potentials to evaluate their accuracy. The performance depends on the choice of vdW‐functional significantly. The vdW‐DF3‐opt1 functional shows the best performance. The deviation ratios of calculated interaction energies of the complexes using the vdW‐DF3‐opt1 functional to CCSD(T) level interaction energies at the potential minima are −6 to 14 %. As a general tendency, the accuracy is improved in the order of vdW‐DF, vdW‐DF2, and vdW‐DF3, but even if they belong to the same group, the accuracy greatly differs depending on each functional. The calculations of hydrocarbon molecules show better performance compared with heteroatom containing molecules in most cases. The calculations using the vdW‐DF3‐opt1 functional and the best dispersion corrected DFT calculations show nearly identical performance.

Watermelon rind derived carbon monolith as potential regenerable adsorbent for perchlorate

Present work describes the preparation of porous carbon block from watermelon rind, as an efficient adsorbent for perchlorate contaminant. Freeze drying, followed by carbonization yielded a highly mesopore dominated porous carbon block, will suitable for water purification. Carbon block (WRPC-Mag), with high surface area of 867 m2g−1 showed highest ever reported perchlorate removal efficiency of 1496 mg g−1. The highest efficiency is attributed to the presence of naturally occurring hetero atoms present in the raw material, which act as in-situ chemical activating agent. Easy recovery of spent adsorbent is achieved by magnetic functionalization of carbon block. Watermelon rind derived carbon block is an efficient, economic, handy and novel candidate for perchlorate removal.

Graphene oxide-gastrointestinal drugs for no side effect: Ultrasound synthesis and characterization

Graphene oxide nanosheets compound (GO) was synthesized and characterized by TEM and XRD. Furthermore, the gastrointestinal drugs (GD) were mixed with graphene oxide nanogel (0.1%) by ultrasound to give the nanocomposite (GO-GD). These nanocomposites were used orally to remove the side effects of the pure gastrointestinal drugs. The invitro results on rats proved that no significant side effects were determined. Moreover, this study includes, for the first time, the influence of functional groups and their relationship to possible side effects on humans. In this study, the comparison was based on the use of only two classes of drugs, which are proton pump inhibitors and histamine 2 blockers. A significant number of chemicals for the treatment of the gastrointestinal system have been selected, which are (omeprazole, pantoprazole, esomeprazole, lansoprazole, nizatidine, cimetidine, famotidine, rabeprazol, and ranitidine). Upon further exuding, the chemical composition of the selected chemicals, it was found that they contain a five- or six- membered aromatic ring(s) to which aliphatic groups of long, medium or short chains are linked. Accordingly, chemical functional groups containing hetero atoms, which are sulfur, oxygen and/or nitrogen, were determined for further investigations. Based on this study, it was found that the functional groups have a significant effect on the specific side effects, and therefore, the continuation of such studies will provide later a mechanism to determine the side effects.

(E)-N-(4-(2-(N-benzylidene) hydrazine carbonyl)phenyl)pyridine-4-sulfonamide Schiff bases: Synthesis, spectroscopic characterization, thermo gravimetric analysis and antimicrobial activity

A new library of Schiff base scaffolds comprising pyridine sulphonamide moiety were synthesized from typical conventional method by the reaction of Ethyl 4-(N-methyl-pyridine-4-sulphonamide)phenyl hydrazide with different aromatic aldehydes derivatives containing hetero atom under reduced pressure. All the synthesized molecules were obtained with excellent yield especially the compounds containing hetero nucleus and nitrogen analogue. The chemical structures of sulpho-pyridine based schiff base were authenticated by analytical techniques viz. FTIR, 1H NMR, 13C NMR, Mass spectra and Elemental composition. Newly generated compounds were also analyzed for their thermal behavior and found stable below 250 °C. The synthetic analogue was also subjected to screen for their antimicrobial activity against six pathogens. Results revealed that schiff base comprising hetero-atom, Nitro & methoxy group displayed excellent activity while other scaffolds display moderate activity.

Multi-component synthesis and recent development on heterocyclic compounds: A research

Heterocyclic compounds have a significant role in our daily lives. These compounds make up the biggest and most diverse organic compound family. Heterocyclic compounds have one or more hetero atoms in their molecular structure. The number of heterocyclic compounds is growing fast as a result of extensive synthetic research and their usefulness in synthetic chemistry. They might be cyclic or acyclic. Primarily, they are utilized as medications, agrochemicals, and veterinary goods. In addition, they are used as sanitizers, developers, antioxidants, corrosion inhibitors, copolymers, colouring agents, and anticancer medicines. They are utilized as vehicles in the synthesis of other organic molecules. In this article, we discuss the majority of newly synthesized or extracted biologically active heterocyclic compounds, such as antibiotics like penicillin and cephalosporin and alkaloids like vinblastine, morphine, and reserpine. In this research, we concentrate on multicomponent reactions of several recent synthetic applications of these innovative approaches.

Progress on carbon for electrochemical capacitors

AbstractElectrochemical capacitors bridge the energy gap between conventional dielectric capacitors and batteries. The energy storage mechanism relies on purely physical electrical double‐layer charging (EDL) and the faradaic process involving fast electrochemical redox reactions. These processes are strongly influenced by the surface area, porosity, electrical conductivity of the electrode materials, and the operating potential window of the electrolyte used. Carbonaceous materials play enormous roles in delivering outstanding electrochemical performance in electrochemical supercapacitors (ESCs) due to attractive material features suitable for high charge storage and release. However, due to the purely EDL‐based charge storage mechanism in only carbon‐based ESCs, the achievable energy density is low and hardly meets the high energy density demanding applications. Therefore, various carbon structures such as activated carbon, carbon nanotubes, graphene, and so on are designed and integrated with other hetero atoms or combined with transition metal oxides and polymer components to induce the pseudo‐capacitive contributions via the electrochemical faradaic reaction. Thus, promoting the electrochemical performance of ESC based on the hybrid/composite material attributed to synergistic capacitances from EDLC and pseudocapacitance. Therefore, this review overviews the general perspective of the ESCs based on nanocarbons with various forms trending the progressive research contributions in developing high‐performance ESCs.

Kinetic and thermodynamic evaluation of azithromycin as a green corrosion inhibitor during acid cleaning process of mild steel using an experimental and theoretical approach

Data from experiments and molecular computation were used to evaluate azithromycin as a safe and innocuous corrosion retardant for mild steel in acidic environments. Hydrogen evolution experiments were conducted between 303 and 333 K with and without azithromycin in hydrochloric acid solution. SEM photos and the results of hydrogen evolution demonstrate that azithromycin suppresses steel corrosion in an acidic environment. The inhibition efficiency (IE%) of azithromycin increases with the rise in concentration and the drop in temperature. The maximum IE% (81.36%) was obtained at 800 mg/L of azithromycin at 303 K. The corrosion reaction rates could be described with a first-order rate law. The range of thermodynamic parameters obtained from 303 K to 333 K for entropy (−181.2 to −91.9 J/mol), enthalpy (18.6 to 50.1 kJ/mol), and activation energy (21.2 to 52.7 kJ/mol) indicate the corrosion is spontaneous and endothermic. The results of the experiment agreed with the Langmuir model for adsorption, and physisorption is postulated for the adsorption of azithromycin on mild steel based on the ΔG values (−12.0 to −2.8 kJ/mol) which were below −20 kJ/mol. According to computational details, oxygen hetero atoms with relatively very large Mulliken charges are the most susceptible active locations for adsorption of Azithromycin on the metal surface.

Microwave assisted synthesis of fluorescent hetero atom doped carbon dots for determination of betrixaban with greenness evaluation.

A simple, rapid and eco-friendly method for synthesis of nitrogen and sulfur doped carbon dots (N,S-CDs) is described. The method involved one step carbonization assisted by a green microwave irradiation route using available and cheap sources, as sucrose (source for C) and thiourea (source for N and S). The formed aqueous solution of N,S-CDs showed excellent optical and electronic properties with high compatibility and stability. The particles of the prepared dots were spherical with a narrow range of size from 1.7 to 3.7 nm with a quantum yield of 0.20. These dots act as a fluorescent probe, as they showed an intense blue fluorescence at 413 nm after excitation at 330 nm. The N,S-CDs were utilized for determination of the anticoagulant drug, betrixaban maleate (BTM), based on quenching of their fluorescence upon its gradual addition. The quenching process was found to be through an inner filter effect mechanism. The proposed method showed a good linearity over a concentration range of (1.0-100.0 μM) with LOD and LOQ values of 0.33 μM and 0.99 μM, respectively. All validation parameters met the acceptance criteria according to ICH guidelines. The high specificity and sensitivity of the performed method contributed to further assay of BTM in dosage form and spiked human plasma sample with high percent recoveries and low values of RSD. Interference from co-administered drugs was studied. Finally, the greenness of the proposed method was evaluated adopting a ComplexGapi approach, the excellent green profile has supported its applicability in quality control laboratories.

Samarium-Mediated Asymmetric Synthesis

Samarium is an efficient reducing agent, a radical generator in cyclization and a cascade addition reaction. Interestingly, samarium metal has crucial impact on numerous C-C and C-X (X = hetero atom) bond forming transformations. It has been established as an exceptional chemo-selective and stereoselective reagent. The reactivity of the samarium catalyst/reagent is remarkably enhanced in the presence of various additives, ligands and solvents through effective coordination and an increase in reduction potential. It has inherent character to act as electron donor for a wide range of transformations including the asymmetric version of various reactions. This review accentuates the developments in samarium-mediated/catalyzed asymmetric organic synthesis over the past 12 years, where the chirality has been induced from ligand, a nearby asymmetric center within the substrate or through coordination directed stereospecific reactions.

Structure-Reactivity Insights on the Alkaline Hydrolysis of Organophosphates: Non-Leaving and Leaving Group Effects in a Bilinear Brønsted-Like Relationship.

The high toxicity of organophosphates, along with its wide use as agrochemicals and chemical warfare, urges efficient degradation methods. Alkaline hydrolysis stands out, which is strongly structure-dependent. The alkaline hydrolysis of various organophosphates is described using a bilinear variation of the Brønsted equation, which evaluates concomitantly the effect of the leaving and non-leaving groups. Over 50 reactions were successfully correlated linearly and the contribution of the usually underestimated non-leaving group seems to be as important as the leaving group. The hetero atom effect (P=O and P=S) seems to vary the contribution of these groups. This concise understanding of the structure-reactivity relationship allows to predict optimal neutralization processes and is key for chemical security, saving time, resources and avoiding unnecessary manipulation of toxic chemicals.

Cellulose Supported Propylamine/Molybdate Complex: A Novel and Recyclable Nanocatalyst for the Synthesis of Pyranopyrimidine Derivatives

Background: Carbon-based materials, due to their unique properties such as lightweight, different forms, doping capability with hetero atoms, low cost, and ease of processability, are suitable support, for heterogeneous catalysts. Among them, cellulose, as one of the most abundant and renewable organic polymers, preserves a key position in many organic raw materials. Pyranopyrimidine derivatives, due to their high biological activity are of interest to both medicinal chemists and biochemists. Moreover, they play the most fundamental structural role in many natural compounds and are medicinally useful molecules. Owing to the great variety of biologically active pyridines, it is not surprising that the pyridine ring system has become a vital basic component in many pharmaceutical agents. Method: In this study, cellulose as a heterogeneous support was used to prepare an efficient solid catalyst. Cellulose, as the most abundant organic polymer, is a suitable material for this purpose. Then, by immobilizing polyoxomolybdate by a linker on the surface of this carbon-based material, we succeeded in producing Cell@(CH2)3N=Mo[Mo5O18] nanocatalyst. The structure and properties of this catalyst were confirmed by various analyses including FT-IR, XRD, EDS-map, FESEM, and TGA, and its efficacy was evaluated by its use in the preparation of Pyrano[2,3- d]pyrimidine derivatives through a multicomponent reaction between aryl aldehydes, malononitrile, and barbituric acid. Results: The results of this study showed that this new and non-toxic organo-inorganic hybrid nanocatalyst provides the desired products in a short time and with appropriate efficiency. Conclusion: The key features of the present protocol include reusability of the catalyst, ease of recovery, ambient reaction conditions, and simple work-up procedure that make it economic and sustainable.

Thickness-Tunable Growth of Composition-Controllable Two-Dimensional FexGeTe2.

Two-dimensional (2D) magnetic materials provide an ideal platform for investigating novel magnetism and spin behavior in low-dimensional systems while being restricted by the deficiency of accurate bottom-up synthesis. To overcome this difficulty, a facile and universal flux-assisted growth (FAG) method is proposed to synthesize the multicomponent FexGeTe2 (x = 3-5) with different Fe contents and even alloyed with hetero metal atoms. This one-to-one method ensures the stoichiometry consistency from the FexGeTe2 and MyFe5-yGeTe2 (M = Co, Ni) bulk crystal precursors to the 2D nanosheets, with controllable composition. Tuning the growth temperatures can provide thickness-tunable products. Changeable magnetic properties of FexGeTe2 and alloyed CoyFe5-yGeTe2 are substantiated by the superconducting quantum interference device and reflective magnetic circular dichroism. This method generates thickness-tunable high-crystallinity FexGeTe2 samples without phase separation and exhibits a high tolerance to different substrates and a large temperature window, providing a new avenue to synthesize and explore such multicomponent 2D magnets and even the alloyed ones.

Atomically engineered molybdenum di-sulfide by dual heteroatom doping for accelerating hydrogen evolution reaction on cadmium sulfide nanorods

Two-dimensional transition metal dichalcogenides (TMDs) with layered nanostructures show promise as non-precious, noble-metal-free water splitting/hydrogen evolution substances. In TMDs, catalytic activity depends on exposed edges because basal planes are inactive. Changing basal planes into catalytically active sites is a challenge. Doping MoS2 with transition metals renders the surfaces of its basal planes catalytically active. Herein, we attempt to activate in-plane surface of MoS2 by doping transition metals (Fe and Co) into the crystal structure, which induces the in-plane sites for catalytic processes, and this doped MoS2 adorned to the CdS nanorods. Incorporating heteroatoms aids in the acceleration of catalytic kinetics, as the obtained activity is comparable to that of single metal doped MoS2/CdS. A remarkable hydrogen production rate of 350 mol h−1 and a 58-fold times improvement observed in optimal FeCo–MoS2 loaded CdS nanocomposite compared to that of pure CdS. This enhancement is due to the synergistic of the hetero atom doped MoS2, which enables for the efficient separation of the photogenerated charge carriers and elevates the surface shuttling characteristics for effective hydrogen production. Greater number of edge sites, increased charge carrier transport, and the introduction of new active sites are all responsible for this remarkable photocatalytic activity. For spatial separation and transportation, these concurrent principles can change physiochemical properties including active sites, surface area, band-edge potentials, and electrical conductivity. To the best of our knowledge, the current catalytic system outperforms all other MoS2 based CdS hybrids that have been reported thus far.

Review on green multicomponent synthesis of heterocyclic compounds

Heterocyclic compounds are of very much concern in our daily life. These compounds constitute the largest and most varied family of organic compounds. Heterocyclic compounds have one or more hetero atoms in their structure., Day by day the number is increasing rapidly due to the enormous synthetic research and also their synthetic utility. They may be cyclic or non-cyclic in nature. They are predominantly used as pharmaceuticals, as agrochemicals and as veterinary products. They also find applications as sanitizers, developers, antioxidants, as corrosion inhibitors, as copolymers, dye stuff and anticancer drugs. They are used as vehicles in the synthesis of other organic compounds. In this review, we cover most biological active heterocyclic compounds that it’s recently synthesized or extracted from the plants e.g. antibiotics such as penicillin’s, cephalosporin; alkaloids such as vinblastine, morphine, reserpine etc. have heterocyclic moiety.

Atom Absorption Energy Directed Symmetry-Breaking Synthesis of Au-Ag Hierarchical Nanostructures and Their Efficient Photothermal Conversion.

Asymmetric plasmonic hierarchical nanostructures (HNs) are of great significance in optics, catalysis, and sensors, but the complex growth kinetics and lack of fine structure design limit their practical applications. Herein, a new atom absorption energy strategy is developed to achieve a series of Au-Ag HNs with the continuously tuned contact area in Janus and Ag island number/size on Au seeds. Different from the traditional passive growth mode, this strategy endows seed with a hand to capture the hetero atoms in a proactive manner, which is beyond the size, shape, and assembles of Au seed. Density functional theory reveals ththe adsorption of PDDA on Au surface leads to lower formation energy of Au-Ag bonds (-3.96eV) than FSDNA modified Au surface (-2.44eV). The competitive adsorption of two ligands on Au seed is the decisive factor for the formation of diverse Au-Ag HNs. In particular, the Au-Ag2 HNs exhibit outstanding photothermal conversion capability in the near-infrared window, and in vivo experiments verify them as superior photothermal therapy agents. This work highlights the importance of the atom absorption energy strategy in unlocking the diversity of HNs and may push the synthesis and application of superstructures to a higher level.

Graphene oxide, kaolinite clay and PVA-derived nanocomposite aerogel as a regenerative adsorbent for wastewater treatment applications

Present work addressed the polyvinyl alcohol (PVA)-assisted gelatinisation of thoroughly dispersed graphene oxide (GO) and Kaolinite clay sheets into hydrogel, followed by lyophilisation to prepare the lightweight (0.024 g.cm−3) and remarkably porous (96.6%) clay-GO-PVA (CGP) composite aerogel by removing of frozen water (ice) through sublimation. The macroporous channels in CGP aerogel besides the mesoporosity of constituent materials facilitated the mass transfer (wastewater) and enhanced the accessibility of surface-active sites for dye adsorption. The CGP aerogel enriched with ample oxygen functionalities exhibited negative zeta potential (−25 mV), facilitating higher adsorption of cationic dyes than anionic ones. The excellent fitting of MB dye adsorption by Langmuir equilibrium isotherm suggested uniform dye adsorption on the surface of CGP aerogel with a maximum adsorption capacity of 535 mg.g−1. The spectroscopic analyses (XPS, FTIR, Raman) revealed charge-driven electrostatic attraction, hydrogen linkages (dipole-dipole and Yoshida), π-π, and n-π interactions between the surface-active sites of CGP aerogel and organic dyes as major adsorptive pathways. The MB dye adsorption increased with temperature and gradually declined with increasing ionic strength of simulated wastewater. The weak acidic to neutral pH range showed higher adsorption of MB dye by CGP aerogel. The size, charge, and hetero atoms of organic dyes, surface-active sites, charge, and porosity of aerogel, along with accessibility to adsorption sites through structural porosity, governed the adsorption process. The CGP aerogel showed excellent regenerability for subsequent batches and exhibited 98% MB dye removal efficiency even after seven adsorption-desorption cycles. Such porous nanocomposite aerogel shows immense potential for wastewater treatment applications to remove organic pollutants.

Microwave Irradiated Synthesis of Pyrimidine Containing, Thiazolidin-4- ones: Antimicrobial, Anti-Tuberculosis, Antimalarial and Anti-Protozoa Evaluation

Aim: This study aims to synthesize thiazolidine-4-one compounds with a pyrimidine nucleus and evaluate against different species of bacteria, fungi, protozoa, and the malaria parasite. Background: Microwave irradiation was the best method for synthesizing the thiazolidin-4-one ring system. It took only 15 minutes for synthesizing thiazolidin-4-one while the conventional method required 12 hours. The rapid reaction was the main concern of this research. Objective: Pyrimidine and Thiazolidin-4-one nucleus have broad-spectrum biological activity and when it is introduced with other hetero atoms containing moiety, many types of biological activities have been found; antimicrobial, anti-tuberculosis, anti-protozoa, antimalarial are the main activities. The activity of these compounds inspired us to do extra research on Thiazolidin-4-one fused pyrimidines with different functional groups. The aim of this study is to synthesize a combination of these two ring systems in less time by using a microwave irradiation method and to evaluate new compounds for different bioactivity. Method: 2-(4-Chlorophenyl)-3-(4-(substituted phenyl)-6-(substituted aryl) pyrimidin-2-yl) thiazolidin- 4-ones (6A-J) were synthesized by microwave irradiation to save energy and time. The structure of all newly synthesized motifs was characterized by spectral analysis (1H NMR, 13C NMR, IR, spectroscopy) and screened for antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pyogenes, antifungal activity against Candida albicans, Aspergillus niger, Aspergillus clavatus, anti-tuberculosis activity against M. tuberculosis H37RV, antimalarial activity against Plasmodium falciparum and anti-protozoa activity against L. mexicana and T. cruzi. Result: Because of microwave irradiation synthesis, time period is very less for preparing the new compound. Biological response given by compounds 6B, 6C, 6D, 6E, 6G, 6H, and 6J was found excellent. Conclusion: Good yield with purity of the newly synthesized thiazolidine-4-one compounds obtained in less time by using microwave irradiation. The biological response of some of the compounds of this series was found excellent.

Performance assessment by experimental and Theoretical approaches of newly synthetized benzyl amide derivatives as corrosion inhibitors for carbon steel in 1.0 M hydrochloric acid environment

• The anticorrosion effect of two inhibitors on C-steel in 1 M HCl was studied. • The polarization results show that (HBEDA) and (HBDETA) are mixed-type inhibitors. • The impedance data suggest the adsorption of the inhibitors on C-steel surface. • The Langmuir adsorption isotherm governs the adsorption mechanism. • QC and MC show that hetero atoms serve as active sites to facilitate adsorption. As part of the efforts made by many researchers to evaluate a lot of chemical compounds as inhibitors for carbon steel corrosion, this research focuses on novel two compounds of benzamide derivatives. The investigated compounds namely N, N -bis (p-hydroxybenzoyl) ethylenediamine (HBEDA) and N, N -bis (p-hydroxybenzoyl) Diethylenetriamine (HBDETA), were formulated then characterized using FTIR, 1 HNMR, and elemental analysis to elucidate the structures chemically. Theoretical and experimental (electrochemical and morphology) studies made clear that (HBEDA) and (HBDETA) improve carbon steel (C-steel) inhibition efficiency in 1 M hydrochloric acid as concentrations increase (25, 50, 100, 150, 200, 250 ppm). The benzamide derivatives acted as interface corrosion inhibitors in an electrochemical impedance spectroscope (EIS) experiment, and they acted as mixed type corrosion inhibitors in a polarization test. They yielded best efficiency gains of 95.8 percent for HBEDA and 99.6 percent for HBDETA. Information collected from the EIS technique was studied in order to represent the corrosion inhibition procedure using an equivalent circuit (EC). The elevated K ads values and negative ΔG ads (-28.71, −28.79 kJ/mol) values of the two compounds (understudy) revealed that they were strongly and spontaneously adsorbed at C-steel/electrolyte connections respectively, and the adsorption isotherm of Langmuir fitted widely with the empirical data. The Surface examination (morphology) of metal employing energy dispersive X-ray (EDX) and scanning electron microscope (SEM) evaluations confirmed the adsorption of (HBEDA) and (HBDETA) on the substrate (C-steel).

Biomass‐derived Sugar Ionic Liquid as a Sustainable Organocatalyst: An Efficient Synthesis of Functionalized Dihydropyrano Coumarins

AbstractMulti‐component reaction approach was utilized in the synthesis of dihydropyrano coumarins under mild reaction conditions. Biomass derived carbohydrate was used as sugar source for the formation of D‐ribose based sugar ionic liquid. The developed catalyst catalyzed efficient synthesis of these hetero atom functionalized compounds. A wide range of substrates were prepared with substituted aliphatic or aromatic aldehydes. Substitution in phenyl ring did not affect the rate of reaction much. All compounds were obtained in good to excellent yield up to 76–92%. The recyclablity of the catalyst was also examined.