Journal of Heterocyclic Chemistry最新文献

Naphthoquinone derivatives are increasingly recognized for their wide-ranging biological activities and relevance in drug discovery. This review outlines recent advances in the synthesis of naphthoquinone compounds, focusing on strategies that enhance their structural diversity and efficiencies. We explored their broad therapeutic potential, including strong antimicrobial effects against both gram-negative and gram-positive pathogens and their capacity to overcome microbial resistance. Their antimalarial activity also shows promise, offering new options for the treatment of drug-resistant species. In oncology, several derivatives have demonstrated selective cytotoxicity against cancer cell lines, with distinct mechanisms supporting their development as anticancer agents. Additionally, their antioxidant properties offer protection against oxidative stress, which has implications for chronic diseases and aging-related disorders. Emerging data also indicate neuroprotective effects, particularly in Alzheimer's disease, by modulating oxidative stress and neuroinflammation. These findings underscore the versatility of naphthoquinone derivatives as potential leads in multiple therapeutic areas. By compiling synthetic methods and biological insights, this review provides a comprehensive resource to support future research and the development of naphthoquinone-based drug candidates.

We describe here the preparation of a new class of photosensitizers cyclophane represented by a family of asymmetrical N-bisheterocyclic bis-imidazolium bromide macrocycles. 1H NMR, 2D NMR, mass spectroscopy measurements, crystallographic x-ray structures and photophysical properties of these cyclophane imidazolium salts are described, as well as the evaluation of their anti-microbial activity.

In the present work, the tail approach chemical reactivity of 4-amino-5-hydrazinyl-4H-1,2,4-triazole-3-thiol (1) with trade name as purpald towards various carbonyl groups is exploited to synthesize heterocyclic molecules such as triazine, tetrazine, and thiadiazepine fused and integrated with the triazole scaffold. The controlled and effective reaction of the site-selective hydrazinyl group proceeds smoothly in acidified methanol at ambient conditions under ultrasonic irradiation as an eco-friendly method enhancing product purity with easier work-up in a shorter reaction time compared with conventional methods. It was observed that the final products were obtained in high yields (89%–99%) in 0.25–5 min by the sonochemical method versus 68%–94% by the conventional method in a time range of 2–35 min. Further to this, the economic yields (YE) of the synthesized compounds were calculated to confirm and compare the efficiency of the two different synthetic methods. Moreover, computational studies were conducted to clarify the regiodivergence of tautomeric forms of 1,2,4-triazol-3-yl-hydrazineylidene-6-hydroxypyrimidine-2,4(3H,5H)-dione 26 and elucidate the most optimized tautomer via using density functional theory (DFT). Furthermore, most of the synthesized heterocyclic systems 26, 5, 29, 6, 22, and 24 in the same order, which were fabricated by ultrasonication technique, showed excellent conductivity and low resistivity compared to other investigated scaffolds 3, 8, 11, 12, 14, 16, 17, 19, and 21, depending on electrochemical impedance spectroscopy measurements.

A new solvent-free one-pot method for the synthesis of ethyl 4-oxo-3,4-dihydroquinazoline-2-carboxylates using N-(2-aminobenzoyl) benzotriazoles was developed. In this method, ethyl 4-oxo-3,4-dihydroquinazoline-2-carboxylates were obtained in good yields (20%–85%) by the reaction of N-(2-amino benzoyl) benzotriazoles with diethyl oxalate and ammonium acetate in the absence of solvent.

The significant biological and therapeutic potential of indole compounds has generated attention and necessitated the development of improved methodologies for their efficient synthesis. This review emphasizes the significant advancements in the synthesis of various indole-based six-membered cycloadducts via the inverse-electron-demand Diels–Alder reaction, an effective method yielding highly substituted and enantioenriched products as both dienes and dienophiles for the period 2010–2025. Furthermore, several essential examples of DFT investigations have been incorporated to examine the most favored mechanistic approaches during the corresponding procedures.

This review presents oxazole, which has considerable interest due to its increasing importance in the field of medicinal chemistry. Oxazole is a simple substance that plays an essential role for many pharmacokinetic compounds, such as antibacterial, antifungal, anti-inflammatory, antiviral, antitubercular, anticancer, antiparasitic, antidiabetic, antiobesity, and antioxidant drugs. This study describes many methods for the synthesis of oxazole derivatives.

The fusion of two selenophene ring systems results in five distinct structural types: condensed selenopheno[2,3-b]selenophene, selenopheno[3,4-b]selenophene, 1H,4H-selenopheno[3,4-c]selenophene, 1H,3H-selenopheno[3,4-c]selenophene, and selenopheno[3,2-b]selenophene. Despite their potential, no dedicated studies have exclusively explored this scaffold, which has primarily been employed as a versatile building block across various applications. The synthesis of selenopheno[2,3-b &3,4-b&3,4-c]selenophene and their analogs can be achieved through diverse chemical approaches, including (i) selenation reactions, (ii) Thorpe–Ziegler cyclization, (iii) Stille and Sonogashira coupling, (iv) McMurry cyclization, and (v) Photocyclization reactions, among other methods.

This study focused on the selective introduction of an acyl group at the C7 position of indole via amide photo-Fries rearrangement. Utilizing UV-C as the sole light source, the N-acyl group of indoles was successfully rearranged across the bridging carbon to the α-position. This approach enabled a mild reaction and environmentally friendly conditions. The acyl substituent must be small or aliphatic to undergo successful rearrangement, unlike acyl radicals with larger or aromatic substituents.

The rise of antimicrobial resistance highlights the urgent need for new therapeutic scaffolds. In this work, indene-fused heterocycles bearing thiazolidinone and thiazolopyrimidine frameworks were synthesized from 2-indanone and characterized by spectroscopic methods. The compounds were evaluated against Staphylococcus aureus, Escherichia coli, and Candida albicans. Among them, compounds 5 and 14 displayed potent broad-spectrum activity (MIC = 3.125 μg/mL), equaling chloramphenicol against S. aureus and outperforming cephalothin against E. coli. Structure–activity relationship analysis revealed that electron-withdrawing substituents and fused heterocycles markedly enhanced potency. Molecular docking confirmed strong binding of compounds 5 and 14 to bacterial DNA gyrase B (1HSK), surpassing reference antibiotics. These findings demonstrate the potential of indene-based scaffolds as promising candidates for antimicrobial drug development.

Domino reaction of N-(cyanomethyl)thienopyridinium quaternary salts with o-hydroxybenzaldehydes leads to an effective formation of chromenes, annulated with imidazo[1,2-a]thienopyridine core. N-Cyanomethyl salts of all four isomeric thienopyridines—thieno[2,3-b]pyridinium, thieno[3,2-c]pyridinium, thieno[3,2-b]pyridinium, and thieno[2,3-c]pyridinium have been successfully used for the preparation of chromeno[2′,3′:4,5]imidazo[1,2-a]thienopyridines with moderate to good yields.