Journal of Heterocyclic Chemistry最新文献

In this research, investigation of one-pot multicomponent reactions of (1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3,5-dione (curcumin), primary amines, and activated acetylenic compounds in an aqueous medium at room temperature in the presence of catalytic amounts of silica-coated magnetic nanoparticles functionalized by iminodiacetic acid-copper (Fe₃O₄@SiO₂/IDA-Cu) was studied which was produced 1,4-dihydropyridine-2,3-dicarboxylate in high yields. The advantages of this procedure were easy separation of products and catalyst, high yields of products, reusability of synthesized catalyst, and good rate of reactions.

In an attempt to cultivate energy-stability balance, a series of nitrogen and oxygen-rich high energy density materials were synthesized based on N-substituted 4-hydroxy-3,5-dinitropyrazole and methylene-linked N-amino-1,2,4-bridges. The hydroxy substituent contributed to oxygen content, hydrogen bonding, and tunability via salt formation. On the other hand, the triazole bridge delivered high nitrogen content and thermal stability. All the synthesized compounds were characterized with multinuclear NMR, FTIR, HRMS, and elemental analysis, and their physicochemical and energetic properties were analyzed. Energetic materials 1–5 showed high detonation performance and adequate overall stabilities. Compound 1 exhibited higher density (1.84 g/cm³) and detonation performance (D_v = 8103 m/s, P = 26.9 GPa) in comparison to its reported amino derivative.

One of the most often utilized hydroperoxides in an array of oxidation strategies is tert-butyl hydroperoxide (^tBuOOH, TBHP). The key reasons for rising utility of TBHP are its low cost, environmental friendliness, high efficiency, and ability to replace hazardous or rare heavy metal oxidants. In this sexennial update, we concisely and critically discussed the applications of TBHP in heterocyclic ring formations starting from 2018 to date. Merits and demerits of its utility, scope of a synthetic organic transformation along with mechanistic logistics are the key features of this review.

The present research study involves synthesis of 1,5-benzothiazepines has been prepared, derived from chalcones and 2-aminothiophenol in a catalytic amount of piperidine using different solvent conditions under microwave irradiation procedure with the aim to test their antibacterial activity and effect of different solvents in the synthesis. It resulted in good yield of 1,5-benzothiazepines (3a-j) and proved to be an efficient and environmentally benign procedure. The synthesized compounds were characterized by conventional spectral data and screened for their in vitro antibacterial activity against four pathogenic bacteria using agar diffusion method. The traditional classical heating method takes more reaction time. So, in this study, we have tested microwave irradiation process and found that 2-ethoxy ethanol as an alternative solvent in reducing the reaction time (up to 4–6 min.) with high yield as compared with classical method. The synthesized compounds 3a, 3c, 3d, 3e, 3 h, 3i, 3j exhibit good to moderate antibacterial activity.

Visible-light-mediated formation of tetrahydrobenzofuranone by direct oxidative [3 + 2] cycloaddition via coupling between dimedone and chalcone using eosin-Y as a photoredox catalyst has been reported. The reaction takes place by a radical pathway as evidenced from our experiments and literature. The developed method involves the utilization of visible-light photoredox catalysis for the formation of C-C and C-O bond via abstraction of methylinic hydrogen of dimedone and β-carbon of chalcone as well as coupling between carbonyl group of dimedone and α-carbon of chalcone in tetrahydrobenzofuranone in one-pot procedure. The present protocol shows significant advantages such as the application of visible light as a clean source of energy, green solvent, mild reaction conditions, cost effectiveness, short reaction time, metal free synthesis, easy operation, high atom economy, and broad substrate scope with functional group tolerance. Moreover, outstanding yield of the product obtained up to 82%.

The chemical reactivity of some 6,8-dimethylchromones was studied toward certain heterocyclic enamines. Treatment of carboxaldehyde 1a with the certain enamines proceeded via condensation with concomitant γ-pyrone ring opening. Reaction of carbonitrile 1b with enamine derivatives proceeded through opening of γ-pyrone moiety associated with cycloaddition into the nitrile function. A novel angular chromenopyrazolopyridine and chromenopyridopyrimidines were efficiently synthesized from reacting carboxamide 1c with the current enamines. Moreover, frontier molecular orbitals analysis, electronegativity, global hardness, global softness, ionization energy, and HOMO-LUMO energy gap were calculated by using DFT/B3LYP/6-311++G(d,p) level. Using the GIAO approach, the ¹H and ¹³C NMR spectra were calculated and showed good agreement with the experimental values. Additionally, the nonlinear optical (NLO) properties of the prepared compounds were found higher than urea. MEP was utilized to ascertain reactive sites within the molecules. The produced compounds exhibited varying degrees of inhibitory effect when tested for their antimicrobial and anticancer properties. The evaluation of ADME (absorption, distribution, metabolism, and excretion) parameters indicated good drug-like properties of all the investigated compounds.

Heteroaryl-1,2,4-triazine complexants are commonly utilized in separation science for the selective chelation of minor An from Ln in simulated high-level waste. To facilitate access to relevant chemical entities for hypothesis-driven inquiry toward improved separations performance, a synthetic method to construct various alkoxy-complexant derivatives was required. In this work, a convergent synthetic strategy for the production of 3,3′- and 4,4′-tetraalkoxy-bis-1,2,4-triazinyl-2,6-pyridines from readily available starting materials via a dealkylation/alkylation/condensation approach is described. Synthetic method development, substrate scope, preliminary solubility, and hydrolytic stability data in various process-relevant diluents are reported herein.

A practicable method is described for the synthesis of 3-acyl-pyrazolo[1,5-a]pyridines from N-aminopyridines and easily available enaminones via a [3+2] cycloaddition. The reactions proceed well with a broad scope, without using additive (base or oxidant).

2-Vinylanilines are readily accessible substrates, which are undoubtedly one of the best candidates for the construction of diversely nitrogen-containing heterocyclic compounds. Owing to the amine and alkenyl groups in their structures, these frameworks offer a facile, direct, and selective synthetic method. This review describes various cyclization reactions involving 2-vinylanilines catalyzed by transition metals, or under metal-free conditions.

Pyrimidine-based derivatives have attracted a lot of interest in heterocyclic chemistry due to its versatile structure and diverse biological activities. This study provides a comprehensive overview of synthetic strategy of different pyrimidine ring and highlights their biological importance. In this article, we start off by going through the fundamental procedures for the synthesis of pyrimidine scaffolds, including both conventional and contemporary synthetic techniques. These works cover a range of therapeutic domains, such as effects that are anticancer, antibacterial, antiviral, anti-inflammatory, antioxidant, antimalarial, and so on. Moreover, we have summarized with a discussion of future prospects and challenges in the field of pyrimidine heterocyclic chemistry. This thorough review is a significant resource for researchers in medicinal chemistry and related fields since it offers insightful information about the synthetic methods and biological applications of pyrimidine-based derivatives.