Synthesis Of Coumarins Research Articles

Click Chemistry Inspired Design, Synthesis and Molecular Docking Studies of Coumarin, Quinolinone Linked 1,2,3‐Triazoles as Promising Anti‐Microbial Agents

AbstractA series of new coumarin, quinolinone and benzyl linked 1,2,3‐triazole derivatives have been synthesized and screened for their anti‐bacterial and anti‐fungal activities. Results of bioassay indicate that, compounds containing chloro and methoxy substituents in coumarin (6 j), chloro substitution in quinolinone (7 g) and 3‐chloro benzyl analogue (8 f) exhibit excellent anti‐bacterial activities. The results of anti‐fungal activities also reveal that methoxy and chloro substituted coumarins (6 e and 6 j) were highly active against yeast strains. In addition, chloro and methyl substituted coumarins (6 h and 6 i) were also exhibited excellent activity. Further, methyl substituted quinolinone with chloro substituted coumarin (7 f) was found to highly active against yeast fungi and filamentous strain A.niger. It is evident from the results obtained and SAR studies that electron withdrawing or donating character of the substituents do not seem to be a major factor in increasing or decreasing anti‐microbial activity.

One Step Synthesis of Coumarinfrom Cinnamaldehyde via Cinnamic Acid Intermediate

The purpose of this study was to develop an efficient method for the synthesis of pharmacologically interesting coumarin (1-benzopyran-2-one) from readily accessed natural products, in particular cinnamaldehyde. One step methodology for the synthesis of coumarin has been developed from cinnamaldehyde. A coumarin was synthesized smoothly via addition of chloro sulfonic acid to cinnamaldehyde. All the products have been confirmed by Thin Layer Chromatography and Gas Chromatography Mass Spectromatry analysis data.

Coumarin–derived Organosilatranes: Functionalization at magnetic silica surface and selective recognition of Hg2+ ion

This article features the first synthesis of coumarin based triazole linked organosilatranes (3–5) derived from terminal alkyne (1) via click methodology. The coumarin tethered organosilatranyl moiety was anchored on magnetic silica surface and was well characterized by numerous spectroscopic and analytical techniques. The resultant hybrid nanoparticles have been characterized in detail by FTIR, UV–vis spectroscopy, Photoluminiscence (P.L), SEM, TEM, XRD, EDX and TGA. The silatranes (3–5) were then assessed for their metal ion binding properties using absorption and emission spectra. It was observed that the synthesized compounds showed significant selectivity for Hg (II). In addition, the interacting ability of coumarin based derivatives was investigated at different pH values and the pH 9 was considered to be the most favorable pH for fluorometric analysis. Importantly, the hybrid nanoparticles possessed enhanced sensorial ability towards Hg2+ ion and these findings were affirmed using stern volmer equation. In addition, the complexation mode of silatrane (3) with Hg2+ ion was also elucidated by computational analysis using DFT study.

Co‐immobilization of Laccase and TEMPO in the Compartments of Mesoporous Silica for a Green and One‐Pot Cascade Synthesis of Coumarins by Knoevenagel Condensation

AbstractCo‐immobilization of bio‐ and chemocatalysts produces sustainable, recyclable hybrid systems that open new horizons for green cascade approaches in organic synthesis. Here, the co‐immobilization of laccase and 2,2,6,6‐tetramethylpiperidin‐1‐oxyl (TEMPO) in mesoporous silica was used for the one‐pot aqueous synthesis of 30 coumarin‐3‐carboxylate derivatives under mild conditions through the condensation of in situ oxidized 2‐hydroxybenzyl alcohols and malonate derivatives. A maximum yield was obtained after incubating at pH 6.0 and 45 °C for 24 h. An efficient organic synthesis was catalyzed by the hybrid catalyst in 10 % organic solvent. More than 95 % of the initial activity of the enzyme was preserved after 10 cycles, and no significant catalyst deactivation occurred after 10 runs. This new system efficiently catalyzed the in situ aerobic oxidation of salicyl alcohols, followed by Knoevenagel condensation, which confirmed the possibility of producing efficient hybrid catalysts by co‐immobilization of catalytic species in mesoporous materials.

Synthesis, α-glucosidase inhibition and molecular docking study of coumarin based derivatives

We have synthesized seventeen Coumarin based derivatives (1–17), characterized by 1HNMR, 13CNMR and EI-MS and evaluated for α-glucosidase inhibitory potential. Among the series, all derivatives exhibited outstanding α-glucosidase inhibition with IC50 values ranging between 1.10 ± 0.01 and 36.46 ± 0.70 μM when compared with the standard inhibitor acarbose having IC50 value 39.45 ± 0.10 μM. The most potent derivative among the series is derivative 3 having IC50 value 1.10 ± 0.01 μM, which are many folds better than the standard acarbose. The structure activity relationship (SAR) was mainly based upon by bring about difference of substituent’s on phenyl part. Molecular docking studies were carried out to understand the binding interaction of the most active compounds.

Synthesis of 3-Phenyl Coumarins by Using Ionic Liquid as Green Solvent

Synthesis of 3-Phenyl Coumarins by Using Ionic Liquid as Green Solvent

Anionic SO3H-functionalized ionic liquid: An efficient and recyclable catalyst for the Pechmann reaction of phenols with ethyl acetoacetate

ABSTRACTThis paper has reported an anionic SO3H-functionalized ionic liquid N-methylimidazolium sulfomethylsulfonate ([Hmim][HO3SCH2SO3]) for the synthesis of coumarins by Pechmann reaction. The [Hmim][HO3SCH2SO3] is easier to prepare by one-step neutralization reaction of N-methylimidazole with methanedisulfonic acid and show high catalytic performance for Pechmann reaction. Besides, the catalyst can simply be separated from the reaction mixture and recycled ten times without noticeable loss of activity.

Enantioselective Synthesis of 2,3‐Dihydrofurocoumarins by Squaramide‐Catalyzed Michael Addition/Cyclization of 4‐Hydroxycoumarins with β‐Nitrostyrenes

AbstractThis work describes the enantioselective synthesis of chiral 2,3‐dihydrofurocoumarins by squaramide‐catalyzed Michael addition of 4‐hydroxycoumarins to β‐nitrostyrenes, followed by a cyclization reaction. A coumarin moiety is present in many chiral bioactive compounds, but the organocatalysis has still not reached its full potential in the synthesis of chiral coumarins. Here, we used squaramide catalysts comprising two chiral units, (S)‐phenylethylamine and cyclohexane‐1,2‐diamine. These catalysts showed high reactivity and enantioselectivity in this transformation. Following this procedure, we prepared a series of 2,3‐dihydrofurocoumarin derivatives in 47‐93% yields and enantiomeric purities in the range of 78‐94% ee. Polystyrene‐immobilized squaramide catalyst performed well for the initial two reaction cycles but then slowly degraded. The absolute configuration of 2,3‐dihydrofurocoumarin products was determined by the comparison of the experimental and density functional theory‐calculated electronic circular dichroism spectra.

Synthesis of 3-Phenyl coumarin by Using Phase Transper as a Green Catalysts

Synthesis of 3-Phenyl coumarin by Using Phase Transper as a Green Catalysts

Design and synthesis of coumarin–imidazole hybrid and phenyl-imidazoloacrylates as potent antimicrobial and antiinflammatory agents

An improved one pot, multi-component synthesis of tri- and tetrasubstituted coumarin–imidazole hybrid has been synthesized at C4 position in good to excellent yield. The reaction was performed under various catalysts and optimization condition results obtained are satisfactory. Wherein, trisubstituted coumarin–imidazole hybrid compounds were converted into phenyl-imidazole acrylates. Further, all the newly synthesized compounds were screened for their antimicrobial activity against Gram-positive Bacillus flexus and Gram-negative Pseudomonas spp. bacterial strains and two strains of fungi studies having Scopulariopsis spp. and Aspergillus terreus organisms. Similarly, antiinflammatory activity of all the compounds was screened against MMP-2 and MMP-9. Both antimicrobial and antiinflammatory results are excellent, among all compounds, sodium acrylate compounds are quite promising against microbial strains and matrix metalloproteins (MMPs). All the isolated compounds were characterized by IR, NMR, and mass spectral analysis.

1,1'-Carbonyldiimidazole (CDI) Mediated Facile Synthesis, Structural Characterization, Antimicrobial Activity, and in-silico Studies of Coumarin- 3-carboxamide Derivatives.

Despite the availability of a variety of antibacterial agents, re-emergence of pathogenic bacteria is still a serious medical concern. So, identification of new, safer, and selective antibacterial agents is the key interest in the medicinal chemistry research. To explore the antimicrobial activity of coumarin-3-carboxamides for a range of bacterial and fungal strains, twenty eight derivatives were synthesized by the reaction of coumarin-3-carboxylic acid with a variety of aniline derivatives in the presence of 1,1'-carbonyldiimidazole (CDI). All compounds were structurally characterized by different spectroscopic techniques EI-MS, HREI-MS, 1H-NMR, 13C-NMR, and evaluated for antimicrobial activities (antibacterial and antifungal). A number of compounds showed good to weak antibacterial activity against various strains of Gram-positive and Gram-negative bacteria. Amongst them, compound 28 displayed noticeable inhibition against five strains of Gram-positive (Bacillus subtilis, Corynebacterium xerosis, Staphylococcus aureus, Streptococcus faecalis, and MRSA) and four strains of Gram-negative bacteria (Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter aerogene, and Shigella dysenteria). However, none of the compounds showed antifungal activity against tested fungi. MIC values were determined for most of the active compounds 2, 15, and 28 against particular bacterial cultures. In silico studies were performed on the most active compound 28 in order to specify and verify the target for antibacterial activity of synthetic coumarin-3-carboxamide derivatives. The cytotoxicity of these compounds on mammalian cells is unknown yet but we are planning to carry out research on the cytotoxic aspect of these compounds in future. The newly identified compounds may serve as lead molecules for the future research regarding the identification of new antibacterial agents.

Facile synthesis of green-light and large Stokes-shift emitting coumarins for bioconjugation

Bright and hydrosoluble fluorescent dyes with large Stokes shifts are widely used as molecular probes and light-emitting markers in chemistry and biology. In this report, one-step synthesis of a bright green-emitting coumarin (Φ = 0.52, λem = 505 nm) was achieved from available reagents under neat conditions. The novel dye 1 showed very large Stokes shift (Δλ = 138 nm) due to strong intramolecular charge transfer (ICT) effect, which was confirmed by density functional theory (DFT) calculations. Dye 1 was hydrosoluble and displayed strong emission at a wide range of pH from 3 to 8. Importantly, the secondary amine in 1 made it extremely convenient for futher bioconjugation. Representative derivatives were showcased for various successful applications of fluorogenic enzyme assay, biolabelling and mitochondrial staining.

Synthesis of 3-cyanomethylated coumarins by a visible-light-mediated direct cyanomethylation of aryl alkynoates.

A visible-light-promoted, mild, and direct cyanomethylation of aryl alkynoates has been developed. This method provides a new strategy toward the synthesis of 3-cyanomethylated coumarins via a domino radical addition/5-exo cyclization/ester migration cascade reaction in moderate to good yields at room temperature. Converting the resulting products into various molecules exhibited the synthetic utility of the present methodology.

Integration of a metal–organic framework with zeolite: a highly sustainable composite catalyst for the synthesis of γ-valerolactone and coumarins

Zr-BDC-MOF and zeolite Beta were entangled to form an efficient catalyst that exhibited excellent activity towards biomass derived liquid γ-valerolactone fuel and coumarin synthesis.

Synthesis and organic solar cell performance of BODIPY and coumarin functionalized SWCNTs or graphene oxide nanomaterials.

The synthesis and characterization of new hybrid materials based on reduced graphene oxide (rGO) or single walled carbon nanotubes (SWCNTs) covalently functionalized by 4,4'-difluoro-8-(4-propynyloxy)-phenyl-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (BODIPY) (2) or 7-(prop-2-yn-1-yloxy)-3-(3',4',5'-trimethoxyphenyl)-coumarin (4) as light harvesting groups have been described. The organic solar cell performances of these novel nanomaterials in P3HT:PCBM blends were investigated. These covalently bonded hybrid materials (reduced graphene oxide:BODIPY (GB), reduced graphene oxide:Coumarin (GC), SWCNTs:BODIPY (CB) and SWCNTs:Coumarin (CC)) were prepared by an azide-alkyne Huisgen cycloaddition (click) reaction between the azide bearing SWCNTs or rGO and terminal ethynyl functionalized BODIPY (2) or coumarin (4) derivatives. The formation of novel nanomaterials was confirmed by FT-IR, UV-Vis and Raman spectroscopies and thermogravimetric analysis. The best performance on P3HT:PCBM organic solar cells was produced by SWCNTs:Coumarin (CC) hybrids which were coated on an indium tin oxide coated polyethylene terephthalate film (ITO-PET). The reference device based on the P3HT:PCBM blend without CC showed a power conversion efficiency (PCE) of 1.16%, an FF of 35% and a short-circuit current density (Jsc) of 5.51 mA cm-2. The reference device with CC hybrids within the P3HT:PCBM blend increased the values significantly to 1.62% for PCE, 40% for FF and 6.8 mA cm-2 for Jsc.

Synthesis, Characterization and Biological Evaluation of Novel Coumarins as Promising Anti-Inflammatory Agents

Synthesis, Characterization and Biological Evaluation of Novel Coumarins as Promising Anti-Inflammatory Agents

Synthesis and Antioxidant Activity of Some New Coumarin Incorporated 4-Thiazolidinone Derivatives

A series of new 4-thiazolidinone derivatives were synthesized by reacting various coumarinyl schiff bases with thioglycollic acid. The intermediate coumarinyl schiff bases were synthesized by reacting 4-hydroxyl coumarin with various substituted anilines in alcohol medium. All the newly synthesized compounds were assigned on the basis of IR, 1H NMR and mass spectral data. All the newly synthesized compounds were evaluated for in-vitro antioxidant activities like DPPH, nitric oxide and hydrogen peroxide radical scavenging assay models. Most of the synthesised compounds showed good antioxidant activity.

Synthesis and Characterization of New Coumarin Substituted Chromone (8-Methyl-4-phenyl-2H,10H-pyrano[2,3-f] chromene-2,10-dione) Using Benzyl Acetoacetate and Studied their Fluorescence Properties

In the present review developed a new method for synthesis coumarin substituted chromone, as they are an important building block in organic chemistry. Also, they are valuable synthetic intermediates in the preparation of new biological relevant heterocyclic system have been synthesized by using effective and efficient synthetic pathway. The synthesized compound has been characterized by FT-IR, 1H-NMR, UV and Mass spectrometry for their structural elucidation. Further, we have studied their fluorescence properties. Graphical Abstract

Visible-Light Photocatalytic E to Z Isomerization of Activated Olefins and Its Application for the Syntheses of Coumarins

Photocatalytic isomerization of thermodynamically stable E-alkene to less stable Z-alkene has been the subject of numerous studies, being successfully achieved mainly under UV irradiation. Recent development of visible light photoredox catalysis has witnessed it emerging as a powerful tool for the access of new structural complexity and many challenging targets. Herein, we report a visible light-promoted E to Z isomerization of cinnamates. When E-isomer of cinnamates was irradiated with blue light in the presence of an organo-photocatalyst, fac-Ir(ppy)3, Z-isomer was exclusively obtained in high yields and with good selectivity. The mild, convenient reaction condition has made this protocol an effective synthetic methodology, which was subsequently implemented in an efficient synthesis of coumarins.

N‐Heterocyclic‐Carbene‐Catalyzed Redox Lactonization of o‐Hydroxycinnamaldehydes and o‐Hydroxycinnamyl Alcohols to Coumarins

AbstractAn N‐heterocyclic carbene derived from 1,3‐dibenzylbenzimidazolium bromide (NHC‐G) not only allowed the intramolecular esterification of o‐hydroxycinnamaldehydes, but also favored the one‐pot domino allylic oxidation/redox lactonization of both (E) and (Z)‐o‐hydroxycinnamyl alcohols, thus these two protocols can provide coumarins in 30–98 % yields in 0.5 h under air. Moreover, the mechanism was also speculated, and it was shown that the presence of oxidants accounted for the formation of coumarins over dihydrocoumarins. This strategy provides a simple, efficient and sustainable route for coumarin synthesis.