Synthesis Of Benzofuran Derivatives Research Articles

Synthesis of Benzofuran Derivatives via a DMAP-Mediated Tandem Cyclization Reaction Involving ortho-Hydroxy α-Aminosulfones.

An efficient cascade cyclization strategy was developed to synthesize aminobenzofuran spiroindanone and spirobarbituric acid derivatives utilizing 2-bromo-1,3-indandione, 5-bromo-1,3-dimethylbarbituric acid, and ortho-hydroxy α-aminosulfones as substrates. Under the optimized reaction conditions, the corresponding products were obtained with high efficiency, exceeding 95% and 85% yields for the respective derivatives. This protocol demonstrates exceptional substrate versatility and robust scalability up to the Gram scale, establishing a stable platform for the synthesis of 3-aminobenzofuran derivative. The successful synthesis paves the way for further biological evaluations with potential implications in scientific research.

Design, Synthesis, Antibacterial Activity, and Mechanisms of Novel Benzofuran Derivatives Containing Disulfide Moieties.

The unsatisfactory effects of conventional bactericides and antimicrobial resistance have increased the challenges in managing plant diseases caused by bacterial pests. Here, we report the successful design and synthesis of benzofuran derivatives using benzofuran as the core skeleton and splicing the disulfide moieties commonly seen in natural substances with antibacterial properties. Most of our developed benzofurans displayed remarkable antibacterial activities to frequently encountered pathogens, including Xanthomonas oryzae pv oryzae (Xoo), Xanthomonas oryzae pv oryzicola (Xoc), and Xanthomonas axonopodis pv citri (Xac). With the assistance of the three-dimensional quantitative constitutive relationship (3D-QSAR) model, the optimal compound V40 was obtained, which has better in vitro antibacterial activity with EC50 values of 0.28, 0.56, and 10.43 μg/mL against Xoo, Xoc, and Xac, respectively, than those of positive control, TC (66.41, 78.49, and 120.36 μg/mL) and allicin (8.40, 28.22, and 88.04 μg/mL). Combining the results of proteomic analysis and enzyme activity assay allows the antibacterial mechanism of V40 to be preliminarily revealed, suggesting its potential as a versatile bactericide in combating bacterial pests in the future.

Synthesis of Benzofuran Derivatives by Diphenylperhydroindolinol Silyl Ether-Catalyzed Asymmetric [3+3] Aza-cyclization ofα,β-Unsaturated Aldehydes

Synthesis of Benzofuran Derivatives by Diphenylperhydroindolinol Silyl Ether-Catalyzed Asymmetric [3+3] Aza-cyclization of<i>α,β</i>-Unsaturated Aldehydes

Synthesis of Benzofuran Derivatives through Cascade Radical Cyclization/Intermolecular Coupling of 2‐Azaallyls

AbstractBenzofurans are among the most popular structural units in bioactive natural products, however, the synthesis of such structures by radical cyclization cascade reactions is rare. Herein, we report a mild and broadly applicable method for the construction of complex benzofurylethylamine derivatives through a unique radical cyclization cascade mechanism. Single‐electron transfer (SET) from 2‐azaallyl anions to 2‐iodo aryl allenyl ethers initiates a radical cyclization that is followed by intermolecular radical–radical coupling. This expedient approach enables the synthesis of a range of polycyclic benzofurans that would otherwise be difficult to prepare.

Synthesis of Benzofuran Derivatives through Cascade Radical Cyclization/Intermolecular Coupling of 2-Azaallyls.

Benzofurans are among the most popular structural units in bioactive natural products, however, the synthesis of such structures by radical cyclization cascade reactions is rare. Herein, we report a mild and broadly applicable method for the construction of complex benzofurylethylamine derivatives through a unique radical cyclization cascade mechanism. Single-electron transfer (SET) from 2-azaallyl anions to 2-iodo aryl allenyl ethers initiates a radical cyclization that is followed by intermolecular radical-radical coupling. This expedient approach enables the synthesis of a range of polycyclic benzofurans that would otherwise be difficult to prepare.

Natural source, bioactivity and synthesis of benzofuran derivatives.

Benzofuran compounds are a class of compounds that are ubiquitous in nature. Numerous studies have shown that most benzofuran compounds have strong biological activities such as anti-tumor, antibacterial, anti-oxidative, and anti-viral activities. Owing to these biological activities and potential applications in many aspects, benzofuran compounds have attracted more and more attention of chemical and pharmaceutical researchers worldwide, making these substances potential natural drug lead compounds. For example, the recently discovered novel macrocyclic benzofuran compound has anti-hepatitis C virus activity and is expected to be an effective therapeutic drug for hepatitis C disease; novel scaffold compounds of benzothiophene and benzofuran have been developed and utilized as anticancer agents. Novel methods for constructing benzofuran rings have been discovered in recent years. A complex benzofuran derivative is constructed by a unique free radical cyclization cascade, which is an excellent method for the synthesis of a series of difficult-to-prepare polycyclic benzofuran compounds. Another benzofuran ring constructed by proton quantum tunneling has not only fewer side reactions, but also high yield, which is conducive to the construction of complex benzofuran ring systems. This review summarizes the recent studies on the various aspects of benzofuran derivatives including their important natural product sources, biological activities and drug prospects, and chemical synthesis, as well as the relationship between the bioactivities and structures.

Intramolecular Cyclization of Aryl Propargyl Ethers: A Straightforward and Convenient Approach to Benzofuran Derivatives

Background: Benzofurans are very important structural motifs found in a great number of natural products and biologically active compounds. Many commercially available drugs, including citalopram, dronedarone, saprisartan, darifenacin, and galantamine are derived from benzofuran core entities. Due to the diversity of benzofuran derivatives in the therapeutic response profile, developing novel and truly efficient methods for their synthesis from low-cost and easily accessible starting materials in one-step has been the subject of number of papers in recent years. Objective: Propargylic ethers are one of the most specific class of heteroatom-containing alkynes showing a large application as intermediates in organic synthesis. These compounds were successfully transformed into various organic compounds, including chromenes, carbazoles, cyclopentanones, 1, 2-dihydropyridines, α, β- unsaturated ketones, alcohols, allenes and many more. Synthesis of benzofurans via intramolecular cyclization of aryl propargyl ethers has become one of the most popular applications of theses versatile compounds. In this review we will highlight the recent discoveries and advances in this interesting research arena. Method: The review is divided into two major sections. The first will discuss cyclization of ortho-halo aryl propargylic ethers, while the second focuses exclusively on cyclization of ortho-unsubstituted aryl propargyl ethers. It is should be mentioned that special emphasis is placed on the mechanistic aspects of these reactions. Conclusion: Synthesis of benzofuran derivatives via intramolecular cyclization of corresponding aryl propargyl ethers have witnessed rapid and comprehensive development in recent years. The main advantages of this synthetic strategy include the use of simple, inexpensive, non-toxic, and readily accessible starting materials, and its pot, atom, and step economy.

Anodic Synthesis of New Benzofuran Derivatives Using Active Methylene Group at Platinum Electrode

A facile and Eco-compatible synthesis of benzofuran derivatives (4a–4h) has been carried out at platinum electrode by electrochemical oxidation of catechol in the presence of active methylene groups. Electro- organic synthesis has been performed in an undivided cell at ambient conditions. The products of electrolysis have been purified and characterized by FTIR, 1H NMR and 13C NMR and mechanism was deduced by voltammetric studies.

Recyclable Pd/CuFe2O4 nanowires: a highly active catalyst for C-C couplings and synthesis of benzofuran derivatives.

Pd/CuFe2O4 nanowire-catalyzed cross coupling transformations are described. Notably, these reactions showed excellent functional group tolerance. Further, the protocol is applied to a one-pot synthesis of benzofurans via a Sonogashira coupling and intramolecular etherification sequence. The catalyst was reused and found to maintain its activity and stability.

Synthesis of benzofuran derivatives as selective inhibitors of tissue-nonspecific alkaline phosphatase: effects on cell toxicity and osteoblast-induced mineralization.

Tissue-nonspecific alkaline phosphatase (TNAP) by hydrolyzing pyrophosphate, an inhibitor of apatite formation, promotes extracellular matrix calcification during bone formation and growth, as well as during ectopic calcification under pathological conditions. TNAP is a target for the treatment of soft tissue pathological ossification. We synthesized a series of benzofuran derivatives. Among these, SMA14, displayed TNAP activity better than levamisole. SMA14 was found to be not toxic at doses of up to 40μM in osteoblast-like Saos-2 cells and primary osteoblasts. As probed by Alizarin Red staining, this compound inhibited mineral formation in murine primary osteoblast and in osteoblast-like Saos-2 cells.

ChemInform Abstract: Synthesis of Functionalized Phenols via the Cascade Reactions of Allenic Ketones with β‐Diketones.

AbstractA broad spectrum of highly substituted phenols/2‐hydroxyalkyl ketones is readily available in a selective manner in the presence of K2CO3 in different solvents.

Intramolecular oxidative coupling: I2/TBHP/NaN3-mediated synthesis of benzofuran derivatives.

A novel intramolecular oxidative coupling reaction has been established to prepare benzofuran derivatives via direct C(sp(2))-H functionalization for the formation of C-O bond. This transformation is mediated by I2/TBHP/NaN3 under metal-free conditions and a catalytic amount of NaN3 plays a crucial role in the reaction. Furthermore, the reaction tolerates a broad substrate scope with average to excellent yields.

ChemInform Abstract: Palladium‐Catalyzed Tandem Reaction of 2‐Hydroxyarylacetonitriles with Sodium Sulfinates: One‐Pot Synthesis of 2‐Arylbenzofurans.

AbstractThe presented approach is suited to be scaled up.

Palladium-Catalyzed Cascade Reactions of 1-(3-Arylprop-2-ynyloxy)-2-bromo Benzene Derivatives with Organoboron Compounds

Applications of the cascade cyclocarbopalladation reaction followed by Suzuki-Miyaura coupling reactions of the readily available aryl-substituted propargylic aryl ethers with arylboronic acid and potassium trans-β-styryltrifluoroborate accomplish a new versatile entry in the synthesis of benzofuran derivatives. Notably, a new approach to the challenging synthesis of C3 functionalized 2-unsubstituted benzofurans has been developed by a cyclocarbopalladation/cross-coupling/aromatization process.

Electrochemical Study of Catechol Derivatives in the Presence of β-diketones: Synthesis of Benzofuran Derivatives

The electrochemical oxidation of 4-(1,3-dithiolan-2-yl)benzene-1,2-diol was studied in the presence and absence of acetylacetone (2a), dimedone (2b) and 4-hydroxycoumarin (2c) as nucleophiles in aqueous solution by means of cyclic voltammetry and controlled-potential coulometry. The results indicate that these nucleophiles participate in Michael addition reaction with the oxidized form of catechol derivatives, and then convert it to the corresponding new benzofuran derivatives. The electrochemical synthesis of compounds has been successfully performed at a carbon rod electrode and in two-compartment cell. The observed homogeneous rate constants (kobs) of the reaction of oxidized form of catechol derivatives with 2a-c as nucleophiles were estimated by comparing the experimental cyclic voltammograms with the digital simulated results. The calculated kobs was found to vary in the order 4-hydroxycoumarin (2c) < dimedone (2b) < acetylacetone (2a).

Synthesis of Benzofuran Derivatives via Rearrangement and Their Inhibitory Activity on Acetylcholinesterase

During a synthesis of coumarins to obtain new candidates for treating Alzheimer’s Disease (AD), an unusual rearrangement of a benzopyran group to a benzofuran group occurred, offering a novel synthesis pathway of these benzofuran derivatives. The possible mechanism of the novel rearrangement was also discussed. All of the benzofuran derivatives have weak anti-AChE activities compared with the reference compound, donepezil.

Synthesis of Benzofuran Derivatives and their Evaluation of Antimicrobial Activity

2‐Acetyl benzofuran (1) was synthesized by refluxing salicylaldehyde and dry chloroacetone in presence of potassium carbonate. The product formed was reacted with 2‐aminobenzothiazole with catalyst p‐toluene sulphonic acid to form N‐[(1Z)‐1‐(benzofuran‐2‐yl)ethylidene]1,3‐benzothiazol‐2‐amine (2). In cold condition, Staudinger reaction was carried out for compound (2) with various acid chlorides in presence of triethylamine to synthesize 4‐[1‐benzofuran‐2‐yl]‐1‐[1, 3‐benzothiazol‐2‐yl]‐4‐methylazetidin‐2‐one (3a-3j). All the synthesized compounds were characterized on the basis of analytical data. The compounds were screened for their antimicrobial activities. Compound 3b,3cand 3d exhibited moderate activity.

A Facile Synthesis of Benzofuran Derivatives: A Useful Synthon for Preparation of Trypsin Inhibitor

Mono-substituted 2-methylbenzo[b]furans were prepared by Claisen rearrangement of corresponding allyl phenyl ethers and subsequent bis(benzonitrile)palladium(II) chloride-mediated cyclization of o-allylphenols.

ChemInform Abstract: Synthesis of Benzofuran Derivatives Using Manganese(III) Acetate Mediated Addition of β‐Dicarbonyl Compounds to Alkyne and Alkenes — A Comparative Study.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Synthesis of Benzofuran Derivatives Through the Coupling of Conjugated Dienynes with Fischer Carbene Complexes.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.