Furan Nucleus Research Articles

Synthesis of furo[2,3-c]quinolinones via intramolecular C(3)–H arylation of furan core under Pd/NHC-catalysis

An efficient procedure for the preparation of furo[2,3-c]-quinolin-4(5H)-ones from 2-furoic acid N-(o-bromoaryl)- amides via selective intramolecular C(3)–H arylation of the furan nucleus involves the catalysis by a Pd/NHC system generated in situ from Pd(OAc)2 and readily available IPrSPh HCl proligand. A series of novel furo[2,3-c]quinolin-4(5H)-ones were prepared in 65–80% isolated yields.

Ilyomycin L, a novel resorcylic acid lactone with furan nucleus from Ilyonectria sp. DWS906

A novel resorcylic acid lactone with furan nucleus, ilyomycin L (1), along with eleven known analogues (2–12) were isolated from the fermentation of the soil-derived fungus Ilyonectria sp. DWS906. Their chemical structures were identified by the comprehensive spectroscopic methods, including 1D/2D NMR and HRESI mass spectra. The absolute configuration of 1 were determined by quantum chemical calculations of the 13C NMR data and electronic circular dichroism (ECD) spectra. The cytotoxicity of all the isolates against the human colorectal cancer HCT116 cell line, as well as their potential protective effects on glutamate-induced injury in the retinal precursor R28 cell line were examined.

Synthesis and biological activity of rhodanine-furan conjugates: A review

Rhodanines are recognized as privileged heterocycles in medicinal chemistry. The main achievements include the development of drug-like molecules with numerous biological activities as well as approved drugs. The Furan nucleus is considered one of the promising heterocyclic cores in medicinal chemistry that showed numerous ranges of activity. The combination of several heterocycles in a one molecule commonly provides much more interest in the enhanced activity profile of its analogs than their parent separate constituents. Such conjugates are promising objects for modern medicinal chemistry. In this review paper recent advances in the synthesis and biological activities rhodanine-furan conjugates which its application in the different field of drug discovery.

Flame retardant epoxy resin toughened and strengthened by a reactive compatibilizer

A flame retardant (FAFD) containing furan groups has been synthesized using furfuryl amine, furaldehyde and 9,10-dihydro-9-oxa −10-phosphaphenanthrene 10-oxide and its use in epoxy (EP) assessed. A reactive compatibilizer (EIA) containing double bonds and EP groups was prepared to modify the interface between FAFD and EP. Incorporation of only 6 wt% FAFD in EP imparts a UL-94 V0 rating and a LOI value of 34.6 vol% for combustion. FAFD exhibits a flame retardant effect in both gaseous and condensed phase. Furthermore, the presence of 1 wt% EIA improves the tensile and impact strength of EP to 77 MPa and 5.7 kJ/m 2 , respectively. This suggests that the compatibility between EP and FAFD is improved greatly in the presence of EIA without loss of flame retardancy. The EP group of EIA can react with EP resin, and the double bond of EIA can react with a furan nucleus of FAFD via Diels-Alder reactions. Thus, the interfacial adhesion between EP and FAFD is increased leading to increased impact and tensile strength of flame retardant EP. This provides a good method for regulation of the performance of flame retardant EP using a small amount of reactive compatibilizer. Flame retardant epoxy is toughened and strengthened by a reactive compatibilizer. • A DOPO-based flame retardant FAFD and a reactive compatibilizer EIA were prepared. • FAFD improves the flame retardancy of epoxy (EP) but decrease its tensile and impact strength. • EIA works as a bridge between EP and FAFD and improve the mechanical properties.

Synthesis and Properties of Furan Derivatives for Epoxy Resins

The discovery of huge petroleum reserves in the 19th century was a golden opportunity that promoted the industrial revolution, by offering a wide variety of cheap raw materials and a reliable source of energy. This caused an unprecedented increase of commodity and production of specialty chemicals in order to fulfill the needs of the global markets. However, as the global warming and the environmental issues has become a hazardous and worried situation, researchers are looking for bio renewable monomers with low toxicity in order to produce more sustainable polymers. This policy was also applied to epoxy resin materials because of their high volume production in industry for a wide range of applications. This review highlights the recent advances in the preparation of diamines and diepoxy monomers for the synthesis of epoxy resins, mainly from 2-furfural, 5-(hydroxymethyl)furfural (5-HMF), and 2,5-furandicarboxylic acid (FDCA), obtained from natural cellulose and hemicellulose feedstocks, respectively, and able to replace phthalic moieties in polyethylene terephthalate. In addition, the processes involved in the monomers preparation, such as reductive amination, etherification, esterification and carbonatation are listed. This review, reporting quasi-exhaustive synthetic pathways of epoxy precursors containing furanic moieties and describing the resulting resins, is composed of seven main parts, based on the synthesis of glycidyl derivatives containing one or two or four furan nuclei bearing or not a spacer between the furan ring and the function. The influence of the substituents on furan moieties (O, CO, CH 2) and the spacer between these groups have also been evaluated. Finally, thermal and a few mechanical properties of the obtained bio-sourced epoxy resins were compared to their fossil fuel analogues (from bisphenol A), featuring the high potential of bio-based monomers as substituents for non-renewable ones.

Synthesis, In Vitro Antitumor Activity and Molecular Mechanism of Novel Furan Derivatives and their Precursors.

Compounds featuring furan nucleus exhibit diverse biological properties. Lots of furan derivatives have been explored as pharmaceutical compounds. Hence it is of great interest to explore furan derivatives and their precursors as antitumor agents. A series of novel furan derivatives and their precursors (1-36) were synthesized from α-haloketones and β-dicarbonyl compounds. The reactions between β-dicarbonyl compounds and α-haloketones under basic conditions produced tricarbonyls or dihydrofurans, which were then condensed into their corresponding furan products. Their potential antiproliferative activity in vitro against two human tumor cell lines-cervical (HeLa) and colorectal (SW620) was evaluated using CCK-8 assay. Compounds 1 and 24 were selected for Western blot analysis. Pronounced anti-proliferative effect in the micromolar level was observed for compounds (1, 4, 17, 20, 21, 24, 27, 31 and 32) in HeLa cells, with their IC50 values ranging from 0.08 to 8.79μM. Additionally, furan compounds (24, 26, 32 and 35) had moderate to potent anti-proliferative activity against the SW620 cell line. Furthermore, the possible targets of these compounds were explored by Western blot analysis. The results indicated that the candidates (compounds 1 and 24) exhibited excellent antiproliferative activity, which may be mediated by promoting the activity of PTEN to suppress PI3K/Akt and Wnt/β-catenin signaling. Most of the furan derivatives and their precursors reported herein exhibited moderate to excellent anti-proliferative activity against HeLa cell line and/or SW620 cell line. Compounds 1 and 24, as well as their analogues may be developed as promising anti-cancer agents.

Recent Updates on Anti-Inflammatory and Antimicrobial Effects of Furan Natural Derivatives.

The furan nucleus is found in a large number of biologically active materials. In recent years, many natural furan derivatives were isolated and their biological effects were investigated. In this review, we focused on the anti-inflammatory and antimicrobial effects of some natural furans and discussed their effects on the immune system. Our investigation revealed that furan natural derivatives have effective antioxidant activities and exert regulatory effects on various cellular activities by modifying some signaling pathways such as MAPK (mitogen-activated Protein Kinase) and PPAR-ɣ (peroxisome proliferator-activated receptor gamma). The antimicrobial activity of these natural compounds was performed through selective inhibition of microbial growth and modification of enzymes. Further studies are needed for isolation and detection of different furan derivatives from natural compounds and investigation of their precise mechanisms for revealing health beneficial effects of these compounds.

Straightforward synthesis of tri- and tetra-substituted 3-trifluoromethylfurans by heterocyclization reaction of perfluoroketene dithioacetals

Various 2-ethylsulfanyl-3-trifluoromethylfurans were obtained, in moderate to good yields, using a two-step procedure, from perfluoroketene dithioacetals as starting materials. Reaction tolerated a large variety of substituents on the furan nucleus. Mechanism of cyclization was also proposed based on the electronic properties of aryl and heteroaryl substituents.

Easy construction of furo[2,3-f]isoindole core by the IMDAV reaction between 3-(furyl)allylamines and α,β-unsaturated acid anhydrides

The vinylogues of furfurylamines, easily available in two steps from furylacroleins (3-(furyl)allylamines), were studied in a tandem N-acylation/intramolecular [4+2] cycloaddition with maleic, pyrocinchonic, and citraconic anhydrides, as well as furylacryloyl and cinnamoyl chlorides. By using a domino reaction of 3-(furyl)allylamines and α,β-unsaturated acid anhydrides under mild conditions, various hexahydro-4H-furo[2,3-f]isoindoles and their carboxyl derivatives were synthesized efficiently. The domino sequence includes three steps: acylation of the nitrogen atom in 3-(furyl)allylamines, intramolecular Diels–Alder cycloaddition in the resulting N-acyl vinylfurans (IMDAV reaction), and prototropic shift of the adducts followed by recovery of aromaticity of the furan nucleus. The key step, IMDAV reaction, leads to the target products, furo[2,3-f]isoindoles, diastereoselectively and with relatively high yields.

Chemoselective photooxygenations of furans bearing unprotected amines: their use in alkaloid synthesis.

Very recent investigations are described, which have shown how basic and unprotected nitrogen functionalities can be included, problem-free, in the furan photooxidation step of singlet oxygen-initiated cascade reaction sequences. The amine groups do not react with singlet oxygen, but, instead, participate later on in the sequences that ultimately yield a diverse range of important alkaloid motifs. To illustrate the versatility of this chemistry, six natural products were synthesised very rapidly and efficiently. Furthermore, all the new technologies operated under green conditions and without the use of a single protecting group.

Synthesis of the Furan Nucleus Promoted by Ytterbium Triflate

An efficient synthesis of differently substituted furans from acetylene dicarboxylates and β-dicarbonyl compounds is described. The furan nucleus was built by means of an Yb(OTf)3 catalyzed cycloaddition reaction yielding desired adducts in 91%-98% yield.

Convenient Synthesis of some new purine analogues incorporating furan nucleus

Sodium 3-(furan-2-yl)-3-oxoprop-1-en-1-olate was used as precursor for synthesis of some novel derivatives of various fused heterocyclic ring systems namely pyrazolo[1,5- a ]pyrimidines, triazolo[1,5- a ]pyrimidines, benzo[4,5]imidazo-[l,2- a ]pyrimidines, pyrazolo[5 , l- c ]triazines, [l,2,4]triazolo[4,3- c ]triazines, benzo[4,5]imidazo[2,1- c ]triazines. The structures of the newly synthesized were established on the basis of their spectral data, elemental analyses and alternate synthetic route whenever possible.

En-route to scarce furo[3,2-f]indolizidines, -indolizidin-9-ols and their stable quaternary ammonium salts based on the stereoselective catalytic hydrogenation of furan nucleus

Catalytic hydrogenation of enantiopure furo[3,2-f]indolizin-6(4H)-one 12, furo[3,2-f]-indolizidine 13 and furo[3,2-f]-indolizidin-9-ol 14 accessible in few steps was studied. High diastereoselectivity was obtained with Rh/Al2O3 for 13 and 14 due to haptophilic effect of both OH and CO groups present in these compounds. In addition, the quaternisation of furo-fused compounds and THF-fused derivatives provided ammonium salts in trans- and cis-relationship, respectively.

Synthesis and biological evaluation of chalcones and acetyl pyrazoline derivatives comprising furan nucleus as an antitubercular agents

A series of 1-{5-[5-(m,p-dichlorophenyl)furan-2-yl]-3-aryl-4,5-dihydro-1H-pyrazol-1-yl} ethanone (3a–k) have been synthesized by the condensation of (2E)-3-[5-(m,p-dichlorophenyl)furan-2-yl]-1-arylprop-2-en-1-one (2a–k) with hydrazine hydrate in glacial acetic acid. The synthesized compounds have been characterized on the basis of elemental analyses and spectral studies. All the synthesized products have been screened for their antibacterial, antifungal, and antitubercular activity.

Synthesis and Muscle Relaxant Activity of Two Analogues of Dantrolene Sodium in Mice

Dantrolene sodium (1) is a skeletal muscle relaxant that is known to act by preventing the release of calcium ions from the sarcoplasmic reticulum. Structure–activity studies of 1 have been limited to changes in the position or the nature of the nitro group, and replacement of the 4-nitrobenzene, furan, and hydantoin moieties with other rings, usually resulting in compounds with reduced or no activity. To investigate the influence of similarities in the electronic transmission ability of the furan nucleus of 5-aryl, 5-arylthio and 5-styryl-2-furancarboxaldehydes on biological activity, two corresponding analogues of 1 were prepared by the reaction of the respective aldehydes with 1-aminohydantoin and were evaluated by the rota-rod test in mice. Compared with 1 as standard, 1-[[[[5-(4-nitrobenzene)thio]-2-furanyl]-methylene] amino]-2,4-imidazolidinedione (2) exhibited higher activity, and 1-[[[[5-(4-nitrobenzene) ethenyl]-2-furanyl]-methylene]amino]-2,4-imidazolidinedione (3) showed comparable activity at 0.5, 3 and 6h after administration to mice. There is a correlation between the electronic transmission ability of the furan nucleus in compounds 1, 2 and 3 and muscle relaxant activity.

Subtype-selective Nav1.8 sodium channel blockers: Identification of potent, orally active nicotinamide derivatives

A series of aryl-substituted nicotinamide derivatives with selective inhibitory activity against the Nav1.8 sodium channel is reported. Replacement of the furan nucleus and homologation of the anilide linker in subtype-selective blocker A-803467 (1) provided potent, selective derivatives with improved aqueous solubility and oral bioavailability. Representative compounds from this series displayed efficacy in rat models of inflammatory and neuropathic pain.

ChemInform Abstract: Synthesis, Antitubercular and Antimicrobial Activity of Some New N‐Aryl‐1,4‐dihydropyridines Containing Furan Nucleus.

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Synthesis, antitubercular and antimicrobial activity of some new N-aryl-1,4- dihydropyridines containing furan nucleus

A wide range of biological activities are associated with 1,4-dihydropyridines Individually or in combination. The synthesis of N-aryl-2,6-dimethyl-3,5-dicarbmethoxy-4-[5'-(m-chloro-p-flourophenyl)-2'-furyl]-1,4-dihydropyridines (6a-J) and N-aryl-2,6-dimethyl-3,5-dicarbmethoxy-4-[5'-(m-chloro-p-flourophenyl)-2'-furyl]-1,4-dihydropyrldines (7a-j) was under-taken with hope that they may be biologically active molecules with improved activity, less toxicity and undesirable side effects. The newly synthesized compounds were characterized on the basis of elemental analysis, IR, 1 H NMR and mass spectral data. All newly synthesized compounds were tested for their antitubercular activity against Mycobacterium tuberculosis H 37 RV ATCC 27294, antibacterial activity against different Gram +ve and Gram -ve bacteria and antifungal activity.

Matrix‐assisted laser desorption/ionization time‐of‐flight structure determination of complex thermoset networks: Polyflavonoid tannin–furanic rigid foams

AbstractPolyflavonoid tannin–formaldehyde–furfuryl alcohol rigid foams yield hardened, rigid, tridimensional networks in which there are covalently linked structures derived from the reaction of their main components. Thus, polyflavonoid tannin structures, tannin–formaldehyde structures, furanic structures derived by the self‐condensation of furfuryl alcohol, and mixed tannin–furane and tannin–furane–formaldehyde structures are all present in the continuous foam networks. Some complex, tridimensional structures involving tannin's flavonoid units, furan nuclei, and formaldehyde‐derived methylene bridges appear to be formed too. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry has been used to determine the different segments contributing to forming the complex thermosetting networks of the hardened foams. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Using Singlet Oxygen to Synthesize Polyoxygenated Natural Products from Furans

[Reaction: see text]. Singlet oxygen is a powerful tool in the armament of the synthetic organic chemist and possibly in that of nature itself. In this Account, we illustrate a small selection of the many ways singlet oxygen can be harnessed in the laboratory to aid in the construction of the complex molecular motifs found in natural products. A more philosophical question is also addressed: namely, how much do singlet oxygen oxidations influence the biogenesis of these natural products? All the synthetic examples surveyed in this Account can be characterized as belonging to the same class because they all involve the oxidation of a substituted furan nucleus by singlet oxygen. Readily accessible and relatively simple furans can be transformed into a host of complex motifs present in a diverse range of natural products by the action of singlet-oxygen-mediated reaction sequences. These reactions are highly advantageous because they frequently deliver a rapid and dramatic increase in molecular complexity in high yield. Furthermore, an unusually wide structural diversity is exhibited by the molecular motifs obtained from these reaction sequences. For example, relatively minor modifications to the starting substrate and to the reaction conditions may lead to products as variable as spiroketal lactones, 3-keto-tetrahydrofurans, various types of bis-spiroketals, 4-hydroxy cyclopentenones, or spiroperoxylactones. In addition, two more specialized examples are discussed in this Account. The core of the prunolide molecules and the chinensine family of natural products were rapidly synthesized using effective and short singlet oxygen mediated strategies; this adds weight to the assertion that singlet oxygen is a very effective moderator of complex cascade reaction sequences. We also show how our synthetic investigations have provided evidence that these same strategies might be used in the biogenesis of these molecules. In the cases of the chinensines and the litseaverticillols, an entire and diverse family of natural products was synthesized beginning from known naturally occurring furan-bearing terpenes. Additionally, in several cases, intermediates in our syntheses have been isolated from natural sources, which suggests that we have followed the same synthetic paths as nature. Certainly, the limit of the synthetic potential of singlet oxygen has not yet been reached, and we can look forward to seeing the boundaries expand in the future in a slew of new and interesting ways.