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Ethyl 2‐amino‐4,5‐diphenylfuran‐3‐carboxylate (2), a reactive synthon, was successfully used to synthesize a novel series of furan and furo[2,3–d]pyrimidinone analogues by interactions with the proper chemical reagents. With the aid of precise spectroscopic data (FT‐IR, Mass, 1H‐NMR, and 13C‐NMR spectra), the structures of products were clearly established. The cytotoxic results by MTT assay showed that furo[2,3–d]pyrimidinone analogues 4 (IC50=6.1±0.8 & 10.2±2.5 μM), 6 (IC50=9.2±2.1 & 17.8±0.5 μM), 11 (IC50=7.1±0.5 & 9.2±1.8 μM), 12 (IC50=5.4±2.3 & 9.8±1.7 μM), 15 (IC50=5.2±2.0 & 8.8±2.0 μM), 18 (IC50=4.2±2.4 & 10.7±1.8 μM), and 21 (IC50=12.8±1.9 & 18.8±0.9 μM) had strong in vitro cytotoxic activities to inhibit the growth of colorectal carcinoma (HCT‐116), and prostate cancer (PC3) cell lines, respectively. However, their effects on normal lung fibroblast (WI‐38) were weak in comparison to 5‐fluorouracil as a positive control. On the other hand, the biological evaluations supported the presence of strong antioxidant activity for the furo[2,3–d]pyrimidinone analogues 4, 6, 15, 17, and 21 (% inhibition=89.10, 84.16, 82.09, 88.11, and 80.23 %, respectively) when compared to ascorbic acid (88.42 %). It has been proven that the most powerful cytotoxic and antioxidant compounds have a superior protective influence on DNA against bleomycin‐induced damage. [ABSTRACT FROM AUTHOR]

Four novel macrocyclic compounds with furan and thiophene were synthesized, characterized by IR, 1H NMR, 13C NMR, and Q‐TOF spectral data. Antimicrobial activities of these compounds were tested against Gram− Escherichia coli ATCC 25922, Gram− E. coli O157 : H7ATCC 43895, Gram+ Staphylococcus aureus ATCC 25923, Gram− Listeria monocytogenes ATCC 19115, Gram− Salmonella typhimurium ATCC 14028 and Candida albicans ATCC 10231. Macrocyclic thioesters were found more efficient against selected microorganisms than other compounds, especially the thioester with thiophene ring notably showed results as effective as reference antibiotic AMP (ampicillin) against Staphylococcus aureus bacteria. DFT calculations on synthesized macromolecules provided insights into their 3‐dimensional geometries and electronic properties. [ABSTRACT FROM AUTHOR]

This study is based on the design, synthesis, and investigation of the physical and chemical properties of furan‐substituted new conjugated organic compounds containing 1,2,4‐triazole core unit. The structures of the synthesized compounds were elucidated by 1H NMR, 13C NMR, and HRMS spectroscopic techniques. The behavior of these compounds in different solvents under UV excitation was investigated. Experimental and computational results were evaluated by examining these behaviors with DFT method. The results show that M1−M6 compounds can be used as a new acceptor core structure for organic electronic devices. By doping these compounds with conjugated or chromophore groups, promising compounds with a low HOMO‐LUMO band gap in light technology can be designed and synthesized. [ABSTRACT FROM AUTHOR]

Arynes are highly reactive intermediates that may be trapped with arynophilic reagents. However, the generation of benzyne necessitates stringent reaction conditions. The cycloaddition reaction of traditional benzyne precursors including diaryliodonium salts with arynophiles under strongly basic conditions encounters the limitations in tolerance of labile functional groups. To overcome this issue, the modulation of diaryliodonium structures are considered by incorporation of specific groups for activation of vinical C−H bond, enabling the generation of aryne intermediates in cycloaddition reactions under mild conditions. In this study, we reported meta‐trifluoromethanesulfonate (OTf) substituted diaryliodonium salts as benzyne precursor, in which the activation of C−I bond and selectively deprotonation of neighboring C−H bond generate highly reactive aryne intermediates for cycloaddition reactions with furans. This approach offers a simple and efficient method for synthesizing bridged ring compounds under mild reaction conditions with good functional group tolerance. [ABSTRACT FROM AUTHOR]

c‐fused furan and their derivatives are widely used as essential components of agrochemicals, bioregulators, dyes, essential skin and hair oils, cosmetics, flavouring agents, photosensitizers in industry and also show a broad range of biological activity. To the best of our knowledge, as of yet, no review has been published that covers the entire synthetic pathway leading to the formation of just c‐fused or 3, 4‐fused furans. In this review, we outline the various pathways for bicyclic, tricyclic, and polycyclic c‐fused furans, along with their detailed mechanisms, concrete examples, and biological activity. We have focused particularly on the synthetic route to medicine, natural products, and their analogues, such as c‐fused furanoditerpenes isospongiadiol, radermachol, a potential folk medicine ingredient, furo[3,4]quinolin‐4(5H)‐ones core, an inhibitor of lymphoma, bhimamycin B, hibiscone‐c core moiety of antibiotic lactonamycin, and analogue of natural product furanether A/ furanether B. Previous approaches and recent methods are described including metal‐free, transition metal, bio‐catalyst, and multi‐substrate approaches with mechanisms. The review covers the literature for more than six decades and presents an overview of the synthesis of different c‐fused furans and their utility in various disciplines such as synthetic chemistry, medicinal chemistry, and drug discovery. [ABSTRACT FROM AUTHOR]

Asthma is a chronic obstructive pulmonary disease which affects the bronchi airways and results in the inflammation of bronchioles along with the hyper‐responsiveness to some direct or indirect stimuli which leads to bronchoconstriction. Substituted xanthines have provided several lead compounds for the development of antiasthmatic agents over the decades. In this present paper, a series of 42 xanthine based derivatives (17 a–g; 18 a–g; 19 a–g; 20 a–g; 28 a–g and 29 a–g) were designed and synthesized. Chemical structures were elucidated by spectroscopic methods. All target compounds were evaluated for their in silico anti‐bronchospasmodic potential using PASS software. Compounds with >95 % potential (18 c–f; 28 a and 29 a–g) in comparison to the standard drug were selected for in vivo bronchospasmodic activity using histamine chamber model. In silico and in vivo activity revealed that the compounds substituted with furan spacer were more active than the cinnamic acid. Substitution with propyl functionality at 1‐and 3‐position of xanthine moiety is also accounted for the enhanced activity of furan derivatives (29 a–g). In conclusion, the synthesized new xanthine derivatives stands out as promising anti‐bronchospasmodic agents for future development. [ABSTRACT FROM AUTHOR]

Treatment of p‐toluenesulfonic acid on bipyrenol in PhCl gave a pyrene‐fused furan. The expansion of the molecule induced a narrow HOMO‐LUMO gap, multiple redox processes showing both oxidation and reduction, and a bathochromic shift in the absorption spectrum. A small Stokes shift was caused by the rigidity of the molecule. The structures and electronic states were estimated by theoretical considerations. We found that the heteroatom containing a [5]helicene molecule shows racemization through a planar transition state. [ABSTRACT FROM AUTHOR]

The catalytic conversion of furan derivatives, furfural and 5‐hydroxymethylfurfural (HMF), to valuable chemicals is of great importance due to the increase in carbon emissions and decrease in fossil fuels. In this manuscript, 1,2,5‐hexanetriol was transformed to HMF through a two steps procedure. The HMF was first hydrogenated to 1‐hydroxyhexane‐2,5‐dione (HHD). The reaction scale could be enlarged from 1 mmol to 50 mmol of the reactant with a similar yield of HHD, and the purity of HHD was over 95 % after a simple extraction. Then the HHD was hydrogenated to 1,2,5‐hexanetriol on Ru/C at very mild reaction conditions. The parameters of pressure, solvent, the concentration of HHD, reaction time and temperature on the hydrogenation of HHD were investigated to find the optimal reaction conditions. The 1,2,5‐hexanetriol could be obtained from HMF in a one‐pot reaction by removing the Pd/C and adding Ru/C after the HMF hydrogenation step. The fresh and used Pd/C and Ru/C were characterized by XRD, TEM, XPS, and the Ru/C was further characterized by EDS mappings. The characterization showed partial agglomeration of Pd occurred after the Pd/C was used. The Ru/C had a narrow Ru distribution and was stable under the reaction conditions. The Ru/C could be used at least 5 times. This manuscript showed an easy route for the production of valuable chemicals from renewable biomass furan derives. [ABSTRACT FROM AUTHOR]

Several furyl/thiophenyl/N‐methylpyrrolyl cores having aldehyde/ketone/ene‐biscarbonyl/diene‐biscarbonyl functions at their 2‐positions were reacted with diazocarbonyl compounds in the presence of metal catalysts. Between the two possible reaction pathways which may take place either on the 2‐substituent of hetaryl or on the core structure, only one of them was dominant for each reaction depending on substituents. Accordingly, in the reaction of thiophene‐2‐carbaldehyde with diazo compounds we obtained epoxy derivatives. On the other hand, dimethyl diazomalonate and furyl‐ene‐diketo/N‐methylpyrrolyl‐ene‐diester yielded only novel dihydrofuran derivatives via [1,5]‐electrocyclic ring closure. However, the reactions of 2‐ene/diene‐diester functionalized furans with dimethyl diazomalonate resulted polymethoxycarboxylate‐substituted oxo‐polyenes chemo‐specifically in good yields. [ABSTRACT FROM AUTHOR]

A series of some new aryl propionic acid derivatives as 2‐(6‐(substituted phenylethynyl)‐2,3‐dihydrobenzofuran‐3‐yl)acetic acids were synthesized. The targeted molecules were prepared by using techniques such as efficient and high‐performance autoclave hydrogenation to reduce highly stable π‐electron system of furan ring and microwave‐assisted rapid Sonogashira Cross‐Coupling reaction between aryl triflate derivatives and substituted aryl acetylenes. The anti‐diabetic screening of selected compounds was performed by using alloxan‐induced diabetic model. The studies include acute and chronic toxicity, effectiveness, change in the behavioral pattern and change in glucose level of the tested animals. The compound 2‐(6‐((4‐ethylphenyl)ethynyl)‐2,3‐dihydrobenzofuran‐3‐yl)acetic acid exhibited maximum anti‐hyperglycemic properties. All the synthesized compounds were characterized by spectroscopic techniques such as 1H‐NMR, 13C‐NMR, IR, Mass spectrometry and single crystal XRD (MTS‐201). [ABSTRACT FROM AUTHOR]

An efficient synthetic protocol was developed for the formation of 2‐allylidene 1,3‐diones in very good yields via [3,3]‐sigmatropic rearrangement of O‐propargyl β‐enones. Good yields of highly functionalized substituted furan derivatives were synthesized from O‐propargyl β‐enones under gold‐catalysis via intramolecular cycloisomerisation. We have developed an efficient method for synthesis of several new 2‐allylidene 1,3‐diones in very good yields under thermal condition via [3,3]‐sigmatropic rearrangement. Further, O‐propargyl β‐enones were directly converted to the corresponding substituted furan derivatives under gold‐catalysis via cyclo‐isomerisation. Moderate to good yields of substituted furan derivatives were generated with significant molecule complexity in one‐pot. [ABSTRACT FROM AUTHOR]

The readily available and inexpensive silver iodide catalyzed one‐pot three‐component reaction of 2‐ketoaldehdyes, secondary amines and terminal alkynes to access 3‐amino furans in environmentally benign water proceeds via tandem Mannich‐Grignard addition followed by intramolecular cyclization was described for the first time. [ABSTRACT FROM AUTHOR]

The synergistic effect of S8‐nanoparticles and β‐cyclodextrin as heterogeneous catalyst system for the synthesis of different benzo[b]furan derivatives from resorcinol and arylglyoxal has been described. This protocol provides a new, environment‐sustainable and simple strategy to construct benzo[b]furans via formation of three new bonds (C−C and C−O) under transition metal‐free conditions. A high catalytic activity and easy recyclability for several times with consistent activity are the additional eco‐friendly aspects of this catalytic system. [ABSTRACT FROM AUTHOR]