Volume 30, Issue 1

As part of our ongoing antileishmanial structure–activity relationship study, a structural simplification of the 3‐nitroimidazo[1,2‐ a ]pyridine ring to a 5-nitroimidazole moiety was conducted. A series of novel 2,4-disubsituted 5-nitroimidazole derivatives, including the 5-nitroimidazole analog of Hit A and the 4-phenylsulfonylmethyl analog of fexinidazole, were obtained by using the vicarious nucleophilic substitution of hydrogen (VNS) reaction, to substitute position 4, and by using the tetrakis(dimethylamino)ethylene methodology to modulate position 2. The molecular structures of eight novel 5-nitroimidazoles were characterized by 1 H NMR, 13 C NMR, LC/MS, and HRMS. The in vitro antileishmanial activity of these compounds was evaluated against the promastigote form of Leishmania infantum and their influence on cell viability was assessed on the human hepatocyte HepG2 cell line. The 4-phenylsulfonylmethyl analog of fexinidazole showed the best selectivity index of the series, displaying good activity against both the promastigote form of L. infantum (EC 50 = 0.8 µM, SI > 78.1) and the promastigote form of Leishmania donovani (EC 50 = 4.6 µM, SI > 13.6), and exhibiting low cytotoxicity on the HepG2 cell line (CC 50 > 62.5 µM).

A novel water-soluble substituted pyridine dicarboxylate containing a quaternary ammonium ion with potential applications in fluorescence cell imaging was synthesized and characterized. Remarkably, this compound exhibited water solubility in the absence of additional solubilizers, enabling direct dissolution in phosphate-buffered saline for cell studies. No obvious cytotoxicity was observed in 4T1 cells (mouse breast cancer cells) within the concentration range of 0.2–25 μmol L −1 , with a cell survival rate above 89%. Furthermore, the compound exhibited a maximum two-photon absorption cross-section of 86 GM at an excitation wavelength of 780 nm, demonstrating high cell permeability, effective distribution in the cytoplasm, and preferential targeting of organelles. Single- and two-photon fluorescence imaging of cells revealed a distinctive blue emission and strong bright green emission, respectively. The newly synthesized substituted pyridine dicarboxylate exhibited low cytotoxicity and strong fluorescence imaging properties, demonstrating its potential in cell imaging applications.

A novel series of meta -diamide compounds incorporating a pyrazole moiety ( 2a – 2v ) were designed and synthesized based on cyproflanilide. Their structures were validated through 1 H NMR, 13 C NMR, and HRMS analyses. These compounds were evaluated for their insecticidal activity against Plutella xylostella, Mythimna separate, Tetranychus cinnabarinus , and Nilaparvata lugens . Most of the title compounds exhibited good activity against N. lugens at 400 mg/L. Compound 2k demonstrated potential for further optimization as an insecticidal lead, thereby extending the application of meta -diamide compounds in the field of sucking mouthparts.

Since many of the U.S. Food and Drug Administration (FDA)-approved medications contain oxygen-containing heterocyclic molecules, they have been discovered to be quite important. Moreover, over the past 10 years, the field of reusable nanocatalysts has expanded quickly. Therefore, the development of nanotechnology has led to a wide range of applications for nanocatalysis in the synthesis of heterocyclic molecules. The domains of organic chemistry and pharmaceuticals have recently shown a great deal of interest in nanocatalyzed organic processes. Such nanocatalysts enable non-toxic, simpler, environmentally friendly, and more affordable synthetic processes that give only the most desirable compounds in higher quantities and provide simple catalyst separation. As a result of their efficient methods for separating catalysts and products, nanocatalysts were chosen over other catalysts for the synthesis of heterocyclic compounds. This review emphasized the preparation of nanocatalysts, synthetic approaches, and recycling studies of highly excited catalytic systems employed for the synthesis of oxygen-containing heterocyclic compounds.

Research on gold catalysis has flourished over the last 20 years, and gold catalysts are now acknowledged as the “best choice” for a range of organic transformations. Gold complexes have emerged as promising candidates for this use in recent years because of their high reactivity, which enables them to induce a broad range of transformations under mild conditions. Extensive demonstrations have showcased the extraordinary efficiency of synthesizing complex organic compounds from the basic starting components. In addition to its traditional applications in catalysis, gold catalysis has expanded to include the total synthesis of natural compounds, which is a complex and demanding undertaking. The class of molecules known as carbo- and heterocycles, which is arguably the most important, has a significant impact on the synthesis of agrochemicals and pharmaceuticals among the numerous additional products made possible by the novel procedures pioneered. The main topic of this review is how to use Au salts in homogeneous catalysis to create cyclization processes for small heterocyclic and carbocyclic systems. This study gives an overview of most of the books and articles written after 2013 that discuss making three- and four-membered carbo- and heterocyclic rings with gold as a catalyst. We have made every effort to include all outstanding reports on this subject; nonetheless, we apologize for any omissions.

Imidazole and its derivatives possess remarkable versatility, finding applications in medicine, synthetic chemistry, and industry. This review explores the latest advancements observed over the last few years (2018–2022), focusing on diverse multicomponent reactions conducted under different conditions. It highlights the role of catalysts and diverse conditions, optimizing synthetic efficiency. The review offers concise insights into emerging trends, making it a valuable resource for researchers and practitioners seeking greener and more efficient imidazole synthesis.

Imidazoles have a unique position in heterocyclic chemistry as these constitute the basic framework of several bio-molecules. Thus, increasing research is being carried out on the synthesis of imidazoles and their derivatives, mainly because of the application of imidazoles in pharmaceutical and medicinal research. Keeping sustainability in mind, researchers are developing synthetic pathways for the synthesis of imidazoles and their derivatives by employing techniques involving green tools, thus leading to sustainable pathways. In this review, we aim to compile such synthetic methodologies involving green tools for the synthesis of imidazoles. The review will cover the synthetic reactions that involve green tools such as microwave irradiation, ultrasound irradiation, and ball milling. We aim to highlight the scope and relevance of such green tools in today’s synthetic research. Through this review, we wish to contribute towards the synthesis of imidazoles that serve as a useful class of heterocyclic compounds involved in the development of pharmaceutically active molecules. We sincerely hope that this review will serve as a relevant guide for future sustainable research in the synthesis of imidazoles and their derivatives.

Triazoles act as important pharmacophores in showing biological activity such as antibacterial, antifungal, antitumour/anticancer, anti-inflammatory activities. Literature review suggests that triazoles have been maximally used in carrying research related activities in reference to biological evaluation as compared to other nitrogen containing five membered heterocycles like tetrazoles, pentazoles, pyrazoles, and imidazoles. The first compound of this class was discovered by Janseen Group in 1960s. The microbes act counteractively towards antibiotics which in turn challenge the efficacy of the drugs and thus create room for the progression of more potent avant-garde drugs. Thus, the synthesis of hybrid molecules has been accelerated from last two decades as the hybrids possess more potency, vigour, and adequacy than its constituting pharmacophores. So, this review represents a condensed report of the research carried out in relation to synthetical procedures and assessment of the antibacterial and antifungal activity of triazoles.