Journal of Heterocyclic Chemistry最新文献

A series of new 4a,7a-diarylperhydroimidazo[4,5-e][1,2,4]triazine-3-thiones were synthesized from 4,5-diaryl-4,5-dihydroxyimidazolidin-2-ones and thiosemicarbazide in high yields, and their interaction with ethyl phenylpropiolate was studied. An effective method for the regioselective synthesis of imidazo[4,5-e][1,3]thiazino[3,2-b][1,2,4]triazines as new heterocycic system derivatives was proposed based on the reaction of aforementioned imidazotriazinethiones with ethyl phenylpropiolate in the presence of MeONa in methanol. The reaction is initiated by a Michael-type addition of the imidazotriazinethiones to the triple bond of ethyl phenylpropiolate followed by intramolecular cyclization.

Here, we have succeeded in developing an eco-efficient, mild, and metal-free synthetic protocol for biologically significant scaffolds: imidazopyridines and their derivatives via radical cyclization from a wide variety of simple 2-aminopyridines and phenacyl bromides as reactants and utilizing visible light as a reaction promoter in the ethanol/water solvent. To the best of our knowledge, the present strategy is the first example of visible light promoted synthesis of imidazo[1,2-a]pyridine via the formation of C-N bonds. The proposed methodology has various advantages namely quick reaction time, low cost, simple setup, high atom efficiency, easy-availability of reactants and non-involvement of specific glasswares and photo reactor system.

The syntheses and bioevaluation of 3-acyl-2-pyridones have garnered significant interest in recent years as a novel class of compounds with diverse biological activities. The bioactivities cover a wide range of therapeutic areas including antimicrobial, antitumor, anti-inflammatory, antifungal, antibiotic, neuritogenic, cytotoxic, and antiviral activities. Therefore, 3-acyl-2-pyridone scaffold offers a versatile platform for the development of new molecules with potential applications in medicinal chemistry. The recent exploration on synthesis and bioevaluation of 3-acyl-2-pyridones has yielded promising results, making them attractive targets for further optimization and development of new therapeutic agents. This review summarizes the available information on total synthesis of 3-acyl-2-pyridone containing natural products, and the other synthetic strategies developed for accessing the 3-acyl pyridones such as multicomponent synthesis, condensation reaction, microwave-assisted synthesis, catalytic hydrogenation reactions, metalation reaction, Michael addition, and formylation reactions. The presented information may serve as a valuable resource for researchers working in the field of medicinal chemistry and drug discovery, stimulating further exploration and development of this intriguing scaffold.

The strategy of isosteric replacement of the benzene ring with a thiophene core was applied in the design of phthalocyanine 1 with the aim for reaching an effective organic chromophore as employable content in organic photovoltaic devices. The formation of the desired product was not achieved but the approach created organic small-molecules 2 and 3. These, representing the reactive intermediates, were converted to novel hemiphthalocyanine 4. Although undesired, all exhibit absorbance in the visible region (λ_max ~ 400 nm) and proximity of the HOMO/LUMO band edge (E_g: 2.0–3.5 eV), suggesting that compounds 2–4 behaves as an effective π-conjugated linkers in donor-π-acceptor type dyes for dye sensitized solar cells and related high performing energetic devices.

To identify lead compounds with potent herbicidal activity, a range of pyrimidine derivatives containing alkenyl groups were designed, synthesized, and characterized using nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HRMS). The synthetic pathways for producing these compounds involved substitution reactions, cyclization, hydrolysis, and other processes. The starting materials for each reaction step were readily accessible, facilitating synthesis. The purification of the final product was straightforward, yielding approximately 80%, under mild reaction conditions. Moreover, a pot culture experiment was employed to assess the herbicidal efficacy of the aforementioned compounds. Compounds 6a, 6b, 6h, and 6j demonstrated a significant inhibition against Amaranthus retroflexus, comparable to fomesafen at 150 g a.i./hm². This suggests that these compounds hold promise as potential lead structures for herbicidal agents. The docking results indicated that the binding energies of compound 6a with protoporphyrinogen oxidase (PPO) were both negative and spontaneous, with numerous interaction active sites. Thus, it is speculated that compound 6a is a PPO inhibitor.

The review is devoted to synthetic methods for the preparation of C-amino 1,2,3-triazoles and their oxides being important precursors in the development of energetic compounds as well as in biological, medicinal, organic, bio-organic, polymer, and material chemistry. This research mainly covers papers published after year 1986.

A novel [4+2] annulation reaction between o-acylamino-aryl MBH carbonates and isatylidene malononitriles has been successfully developed. This methodology exhibits excellent substrate tolerance, affording a series of spiro[indolin-3,2′-quinoline] framework compounds with yields up to 98%. The scalability of the reaction is also noteworthy, as evidenced by the 95% yield of the final product upon a 50-fold scale-up.

Many molecules called coumarins with very varied biological activities and widely used in the food, pharmaceutical, cosmetic, and medical industries. Their structure has a significant impact on their biological activity and their possible applications. Advanced synthesis frequently leads to an increase in the production of various chemical wastes. The amount of hazardous organic substances used and produced is reduced by the application of environmentally friendly synthesis techniques. Numerous techniques are employed in green chemistry, including the use of ionic liquids and deep eutectic solvents, solvent-free synthesis, mechanical synthesis, multicomponent reactions, ultrasound, and microwaves. These green synthesis techniques have been successfully applied to all common condensation reactions for the synthesis of coumarin, including the Perkin, Knoevenagel, Pechmann, Kostanecki-Robinson, and Reformansky reactions. These methods not only reduce the use and production of toxic chemicals, but also improve the yield, purity, and energy consumption of the product. This review summarizes the methods of microwave synthesis of coumarin derivatives, as well as their biological activities.

CO₂ is a significant greenhouse gas, and is considered as a copious renewable carbon reagent. From a synthetic perspective, it can be used as a sustainable and substitute C1 building block because of its nontoxic, nonflammable, and abundant nature. The transformation of a wide range of organic molecules with CO₂ into numerous efficient commodities is a defining feature of recent success in this sector. Because of its numerous applications, photocatalysts and visible light-mediated synthesis of carbamates and cyclic carbonates using CO₂ have drawn a lot of interest from researchers. This mini review mainly focusses on the different one-pot reactions that are proven to be efficacious for chemical fixation of CO₂ in producing industry-based compounds of carbamates and carbonates with the creation of CO, CH, CC, and CN bonds.

Three novel heterocyclic host based on diaryl ketone-tethered 1,5-diazocines were designed and synthesized for applications in phosphorescent organic light-emitting diodes (PhOLEDs). The hosts were derived by anchoring the naphthyl ketone (TBN), anthryl ketone (TBA), and phenanthryl ketone (TBP) to the 1,5-diazocine core. The materials were successfully characterized using spectroscopic techniques. TBN and TBP exhibited low external quantum efficiency of 1.5% and 1.9% when explored as hosts in PhOLED devices. Among the series, TBP exhibited the highest luminance of 4160 cd/m², maximum luminance efficiency of 6.3 cd/A, and power efficiency of 3.21 lm/w, when doped with Ir(ppy)₃ in PhOLED. Nevertheless to our surprise, TBA manifested the lowest device performance than other TBs as a host due to low carrier mobility caused by a highly twisted structure as deciphered from the comparative analysis of single-crystal structure that could impede carrier transport crucial for efficient electroluminescence. The outcomes of electroluminescence were validated and explained with analysis of single-crystal structure, and also with the aid of density functional theory.