An efficient and recyclable nanocatalyst for the green and rapid synthesis of biologically active polysubstituted pyrroles and 1,2,4,5-tetrasubstituted imidazole derivatives

Facile synthesis of FeCeOx nanoparticles encapsulated carbon nitride catalyst for highly efficient and recyclable synthesis of substituted imidazoles

Herein, we developed a novel composite called FeCeOx@g-C3N4 through a combination of sonication, sintering, and hydrothermal techniques to implement the principles of green chemistry by utilizing reusable nanocomposites in one-pot reactions. To gain a comprehensive understanding of the catalyst's structure, composition, and morphology, various characterization methods were employed. These included FT-IR analysis to examine chemical bonds, SEM and TEM imaging to visualize the catalyst's surface and internal structure, TGA to assess thermal stability, EDS for elemental composition analysis, and XRD to determine crystal structure. The FeCeOx@g-C3N4 nanocatalyst demonstrated remarkable efficacy in the one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazole. Noteworthy features of this catalyst included high percentage yield, mild reaction conditions, short reaction time, and an efficient and straightforward procedure. Furthermore, the FeCeOx@g-C3N4 composite exhibited excellent recyclability and reusability. It could be recycled and reused up to four times without a significant decline in catalytic activity.

Insight into the corrosion inhibition of Biebersteinia multifida root extract for carbon steel in acidic medium

In this project, the protective effect of Biebersteinia multifida root extract (BMRE) against corrosion of 1018 low carbon steel (1018LCS) in HCl solutions was appraised by assessing weight loss, electrochemical impedance spectroscopy (EIS), and polarization at 25 °C. The maximum inhibitory efficacy for the concentration of 1 g/l of the BMRE was 92.8% at 25 °C after 2 h and increased to 95.3% after 24 h of immersion. Polarization experiments have shown that the extract in acidic solutions can act as a mixed corrosion inhibitor. The corrosion inhibitory efficacy of BMRE decreased with increasing temperature, and at all temperature settings studied, the adsorption of BMRE molecules on 1018 LCS was consistent with the Langmuir adsorption isotherm. The Scanning Electron Microscopy (SEM) analysis confirmed the protection of 1018 LCS in the acidic solution containing BMRE extract. Quantum chemistry studies of four main constituents of the extract called vasicinone, umbelliferon, scopoletin, and ferulic acid were performed by density functional theory, DFT, in neutral and protonated states. Calculated quantum parameters were used to investigate the active sites and donor-receptor interactions of molecules.

Drug delivery based on chitosan, β-cyclodextrin and sodium carboxymethyl cellulose as well as nanocarriers for advanced leukemia treatment

Medicine/nanotechnology as a new and applicable technique according to drug delivery systems has gained great consideration for cancer treatment. Polysaccharides including, cellulose, β-cyclodextrin and sodium carboxymethyl cellulose and chitosan as natural bio-materials, are appropriate candidates for designing and formulations of these nanosystems because of the exceptional advantages such as bio-compatibility, bio-degradability, non-toxicity, and gelling characteristics. An intelligent drug delivery platform based on these hybrids nowadays is developed, which can be used for dual-responsive dual-drug delivery. Nanotechnology accompany with biological molecules has been carefully considered to decrease the drawbacks of conventional cancer treatments. Consequently, this review is intended to state and investigate on the latest development on the combination treatment of platforms based on the hybrids of anticancer drugs/nanoparticles/Polysaccharides in the fields of biomedical therapeutics and cancer therapy owing to the bio-compatibility, great surface area, good chemical and mechanical features, the challenges and future perspectives are reported as well.

Nanocatalysts: applications for the synthesis of N-containing five-membered heterocycles

Using transition metals as nanocatalysts has opened up a vast new area in heterocyclic chemistry in the modern day. Heterocyclic moieties are significant scaffolds that have both pharmacological and industrial applications. Various scientific groups have focused their attention on the expansion of simple reaction protocols by introducing better functional group compatibilities under mild reaction conditions through the use of easily available starting materials. This review provides an outline of the applications of metallic nanoparticles as proficient, recyclable, low-cost and green heterogeneous catalysts for the preparation of a wide range of key therapeutic five-membered nitrogen-containing heterocyclic compounds as well as some other significant functionalizations over the rings. This review mainly covers the literature published through the period from 2004 to 2021.

Polymer based advanced recipes for imidazoles: a review

Imidazoles and their scaffold are an extraordinarily essential class of nitrogen bearing azole heterocyclic compounds. They have different place in wide area of organic synthesis, which can be utilized in a variety of applications in diverse fields including agriculture, medicine, polymer and various industries. Numerous methods for synthesis of imidazole derivatives are reported in last few decades. Existing conventional methods are more or less significant and confined due to its time-consuming reactions, high cost of catalyst, extensive methodologies, low yield rate or no reusability respectively. Overcoming to inefficient conventional methods, finding of novel and effective methods of imidazole synthesis becomes a crucial step in expanding dynamics of material chemistry. The synthesis and design of imidazole derivatives employing polymer-supported techniques will be discussed in this review. In addition, the utilization of polymer-supported organic, inorganic, hybrid, bio, and nanocatalysts in the synthesis process will be discussed.

An efficient green protocol for the synthesis of 1,2,4,5-tetrasubstituted imidazoles in the presence of ZSM-11 zeolite as a reusable catalyst

In this study, we have synthesized a series of ZSM-11 zeolite catalysts using tetrapropyl ammonium hydroxide as a structure-directing agent through a highly efficient hydrothermal method. The series of catalysts were studied by different techniques such as FT-IR spectroscopy, XRD, FE-SEM, HR-TEM, EDS, pyridine-FT-IR spectroscopy, and BET analysis. We focused on varying reaction time intervals from 18 to 48 hours to investigate the effect on catalytic activities of the synthesized series of catalysts. The percentages of aluminum increased in the framework of zeolites with increasing crystallinity, surface area, external surface area, and acidity in the series of ZSM-11 zeolites by increasing the time from 18 to 48 h. Then, we studied the catalytic activity of a series of ZSM-11 zeolites and found that the ZSM-11 zeolite (48 h) possesses higher catalytic activity towards the synthesis of 1,2,4,5-tetrasubstituted imidazoles under solvent-free conditions. The present protocol scored well with excellent yield, short reaction time, clean reaction profiles, low catalyst loading, and no tedious workup. The catalyst (ZSM-11 zeolite 48 h) was recycled and reused in five runs without any considerable loss of activity and product yield.

TMSOTf-catalyzed synthesis of trisubstituted imidazoles using hexamethyldisilazane as a nitrogen source under neat and microwave irradiation conditions

In the process of drug discovery and development, an efficient and expedient synthetic method for imidazole-based small molecules from commercially available and cheap starting materials has great significance. Herein, we developed a TMSOTf-catalyzed synthesis of trisubstituted imidazoles through the reaction of 1,2-diketones and aldehydes using hexamethyldisilazane as a nitrogen source under microwave heating and solvent-free conditions. The chemical structures of representative trisubstituted imidazoles were confirmed using X-ray single-crystal diffraction analysis. This synthetic method has several advantages including the involvement of mild Lewis acid, being metal- and additive-free, wide substrate scope with good to excellent yields and short reaction time. Furthermore, we demonstrate the application of the methodology in the synthesis of biologically active imidazole-based drugs.

Trisubstituted imidazoles are synthesized efficiently from the readily available 1,2-diketones and aldehydes using hexamethyldisilazane as a new and stable nitrogen source under TMSOTf-catalysis system, microwave heating and solvent-free conditions.

Recent advances in the synthesis of imidazoles

The review highlights the recent advances (2018-present) in the regiocontrolled synthesis of substituted imidazoles. These heterocycles are key components to functional molecules that are used in a variety of everyday applications. An emphasis has been placed on the bonds constructed during the formation of the imidazole. The utility of these methodologies based around the functional group compatibility of the process and resultant substitution patterns around the ring are described, including discussion of scope and limitations, reaction mechanisms and future challenges.