Synthesis and antifungal activities of some aryl [3-(imidazol-1-yl/triazol-1-ylmethyl) benzofuran-2-yl] ketoximes

Construction of 3-Methyl-2-Substituted Benzo[b]furans and 3-Methyl-2-Substituted Benzo[b]thiophenes Using Solid Calcium Carbide as a Substitute for Gaseous Acetylene

A concise method for the facile construction of 3-methyl-2-substituted benzo[b]furans and 3-methyl-2-substituted benzo[b]thiophenes using low-cost, abundant, and easy-to-use solid calcium carbide instead of flammable and explosive gaseous acetylene as an original alkyne source, o-bromophenyl ethers or o-bromophenyl thioethers as substrates through an intramolecular carbanion-yne cyclization in a 5-exo-dig manner, and subsequent double-bond isomerization is described. The simultaneous formation of two C-C bonds is realized in a one-step route. The wide substrate scope, high yield, and simple workup manipulations are also merits of this method. The synthetic strategy can also be suitable for the gram scale.

A sustainable avenue for the synthesis of propargylamines and benzofurans using a Cu-functionalized MIL-101(Cr) as a reusable heterogeneous catalyst

A heterogeneous copper-catalyzed A3 coupling reaction of aldehydes, amines, and alkynes for the synthesis of propargylamines and benzofurans has been developed. Here, the modified metal-organic framework MIL-101(Cr)-SB-Cu complex was chosen as the heterogeneous copper catalyst and prepared via post-synthetic modification of amino-functionalized MIL-101(Cr). The structure, morphology, thermal stability, and copper content of the catalyst were determined by FT-IR, PXRD, SEM, TEM, EDX, TGA, XPS, and ICP-OES. The catalyst shows high catalytic activity for the aforementioned reactions under solvent-free reaction conditions. High yields, low catalyst loading, easy catalyst recovery and reusability with not much shrink in catalytic activity, and a good yield of 82% in gram-scale synthesis are some of the benefits of this protocol that drove it towards sustainability.

Some Novel [6-(Isoxazol-5-ylmethoxy)-3-methylbenzofuran-2-yl]phenylmethanone Derivatives, Their Antimicrobial Activity, and Molecular Docking Studies on COVID-19

A novel series of benzofuran-isoxazole hybrid heterocyclic unit has been synthesized and their structures characterized by ¹H and ¹³C NMR, and mass spectral data. The synthesized products have been evaluated for their in vitro antibacterial and antifungal activity using Gentamycin sulphate and Nystatin as standard drugs, respectively. Four synthesized products have been determined as highly active against all tested bacterial and fungal strains. Structure–antimicrobial activity relationship has been supported by docking studies of the active compounds against glucosamine-6-phosphate synthase and aspartic proteinase. According to the docking studies, all derivatives exhibit good theoretical affinity with Autodock 4.2 software score in the range of –9.37 and –11.63 kcal/mol against the main protease of COVID-19.

Recent Advances of Furan and Its Derivatives Based Semiconductor Materials for Organic Photovoltaics

The state-of-the-art bulk-heterojunction (BHJ)-type organic solar cells (OSCs) have exhibited power conversion efficiencies (PCEs) of exceeding 18%. Thereinto, thiophene and its fused-ring derivatives play significant roles in facilitating the development of OSCs due to their excellent semiconducting natures. Furan as thiophene analogue, is a ubiquitous motif in naturally occurring organic compounds. Driven by the advantages of furan, such as less steric hindrance, good solubility, excellent stacking, strong rigidity and fluorescence, biomass derived fractions, more and more research groups focus on the furan-based materials for using in OSCs in the past decade. To systematically understand the developments of furan-based photovoltaic materials, the relationships between the molecular structures, optoelectronic properties, and photovoltaic performances for the furan-based semiconductor materials including single furan, benzofuran, benzodifuran (BDF) (containing thienobenzofuran (TBF)), naphthodifurans (NDF), and polycyclic furan are summarized. Finally, the empirical regularities and perspectives of the development of this kind of new organic semiconductor materials are extracted.

Nanocrystalline ZnO: A Competent and Reusable Catalyst for the Preparation of Pharmacology Relevant Heterocycles in the Aqueous Medium

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Nanoparticle catalyzed synthesis is a green and convenient method to achieve most of the chemical transformations in water or other green solvents. Nanoparticle ensures an easy isolation process of catalyst as well as products from the reaction mixture avoiding the hectic work up procedure. Zinc oxide is a biocompatible, environmentally benign and economically viable nanocatalyst with effectivity comparable to the other metal nanocatalyst employed in several reaction strategies. This review mainly focuses on the recent applications of zinc oxide in the synthesis of biologically important heterocyclic molecules under sustainable reaction conditions.

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Application of zinc oxide in organic synthesis: Considering the achievable advantages of this nanocatalyst, presently several research groups are paying attention in anchoring zincoxide or its modified structure in several types of organic conversions e.g. multicomponent reactions, ligand-free coupling reactions, cycloaddition reaction, etc. The advantages and limitations of this nanocatalyst are also demonstrated. The present study aims to highlight the recent multifaceted applications of ZnO towards the synthesis of diverse heterocyclic motifs. Being a promising biocompatible nanoparticle, this catalyst has an important contribution in the fields of synthetic chemistry and medicinal chemistry.

One-Pot Allylation-Intramolecular Vinylogous Michael Addition-Isomerization Cascade of o-Hydroxycinnamates and Congeners: Synthesis of Substituted Benzofuran Derivatives

A unique intramolecular vinylogous Michael addition leading to the synthesis of heterocycles has been disclosed. Base-promoted one-pot sequential O-allylation of o-hydroxy-cinnamates or -cinnamonitrile or -chalcones with γ-bromocrotonates followed by an intramolecular conjugate addition of vinylogous Michael donors resulted in the formation of highly substituted benzofuran derivatives in good to excellent yields. The intramolecular event followed by two [1,3]-H shifts leading to aromatization appears to be the key to the success of this unprecedented transformation.

A phenotypic small-molecule screen identifies halogenated salicylanilides as inhibitors of fungal morphogenesis, biofilm formation and host cell invasion

A poorly exploited paradigm in the antimicrobial therapy field is to target virulence traits for drug development. In contrast to target-focused approaches, antivirulence phenotypic screens enable identification of bioactive molecules that induce a desirable biological readout without making a priori assumption about the cellular target. Here, we screened a chemical library of 678 small molecules against the invasive hyphal growth of the human opportunistic yeast Candida albicans. We found that a halogenated salicylanilide (N1-(3,5-dichlorophenyl)-5-chloro-2-hydroxybenzamide) and one of its analogs, Niclosamide, an FDA-approved anthelmintic in humans, exhibited both antifilamentation and antibiofilm activities against C. albicans and the multi-resistant yeast C. auris. The antivirulence activity of halogenated salicylanilides were also expanded to C. albicans resistant strains with different resistance mechanisms. We also found that Niclosamide protected the intestinal epithelial cells against invasion by C. albicans. Transcriptional profiling of C. albicans challenged with Niclosamide exhibited a signature that is characteristic of the mitochondria-to-nucleus retrograde response. Our chemogenomic analysis showed that halogenated salicylanilides compromise the potential-dependant mitochondrial protein translocon machinery. Given the fact that the safety of Niclosamide is well established in humans, this molecule could represent the first clinically approved antivirulence agent against a pathogenic fungus.

Fragmentation of 2-aroylbenzofuran derivatives by electrospray ionization tandem mass spectrometry

We investigated the gas-phase fragmentation reactions of a series of 2-aroylbenzofuran derivatives by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The most intense fragment ions were the acylium ions m/z 105 and [M+H-C₆ H₆ ]⁺ , which originated directly from the precursor ion as a result of 2 competitive hydrogen rearrangements. Eliminations of CO and CO₂ from [M+H-C₆ H₆ ]⁺ were also common fragmentation processes to all the analyzed compounds. In addition, eliminations of the radicals •Br and •Cl were diagnostic for halogen atoms at aromatic ring A, whereas eliminations of •CH₃ and CH₂ O were useful to identify the methoxyl group attached to this same ring. We used thermochemical data, obtained at the B3LYP/6-31+G(d) level of theory, to rationalize the fragmentation pathways and to elucidate the formation of E, which involved simultaneous elimination of 2 CO molecules from B.

Design, Synthesis and Antifungal Activity of Novel Benzofuran-Triazole Hybrids

A series of novel benzofuran-triazole hybrids was designed and synthesized by click chemistry, and their structures were characterized by HRMS, FTIR and NMR. The in vitro antifungal activity of target compounds was evaluated using the microdilution broth method against five strains of pathogenic fungi. The result indicated that the target compounds exhibited moderate to satisfactory activity. Furthermore, molecular docking was performed to investigate the binding affinities and interaction modes between the target compound and N-myristoyltransferase. Based on the results, preliminary structure activity relationships (SARs) were summarized to serve as a foundation for further investigation.

Benzofuran as a promising scaffold for the synthesis of antimicrobial and antibreast cancer agents: A review

Benzofuran as an important heterocyclic compound is extensively found in natural products as well as synthetic materials. Since benzofuran drivatives display a diverse array of pharmacological activities, an interest in developing new biologically active agents from benzofuran is still under consideration. This review highlights recent findings on biological activities of benzofuran derivatives as antimicrobial and antibreast cancer agents and lays emphasis on the importance of benzofurans as a major source for drug design and development.

R. C, Chand K, Santos MA, Keri RS. Benzofuran: an emerging scaffold for antimicrobial agents

The present article systematically gives a comprehensive review of current development of benzofuran-based compounds as antimicrobial agents and the perspectives that they hold for future research.