Current Organic Chemistry - Volume 28, Issue 7, 2024

Among the several peroxides available, meta-chloroperbenzoic acid (mCPBA) plays an efficient role of oxidizing reagent and is used for many oxidative transformations, such as oxidation of various functional groups, carbon-carbon, carbon-hetero bond formation, heterocyclic ring formation, heteroarylation, oxidative cross-coupling, lactonization, oxidative dearomatization, α-oxytosylation or α-acetoxylation, oxidative C-C bond activation and in other miscellaneous reactions. The purpose of this review is to critically discuss the significant contributions of mCPBA along with hypervalent iodine/iodine reagents in organic synthesis from mid-2015 to date.

3D bioprinting is a novel technology that has gained significant attention recently due to its potential applications in developing simultaneously controlled drug delivery systems (DDSs) for administering several active substances, such as growth factors, proteins, and drug molecules. This technology provides high reproducibility and precise control over the fabricated constructs in an automated way. Chitosan is a natural-derived polysaccharide from chitin, found in the exoskeletons of crustaceans such as shrimp and crabs. Chitosan-based implants can be prepared using 3D bioprinting technology by depositing successive layers of chitosan-based bioink containing living cells and other biomaterials. The resulting implants can be designed to release drugs at a controlled rate over an extended period. The use of chitosan-based implants for drug delivery has several advantages over conventional drug delivery systems. Chitosan is biodegradable and biocompatible, so it can be safely used in vivo without causing any adverse effects. It is also non-immunogenic, meaning it does not elicit an immune response when implanted in vivo. Chitosan-based implants are also cost-effective and can be prepared using simple techniques. 3D bioprinting is an emerging technology that has revolutionized the field of tissue engineering by enabling the fabrication of complex 3D structures with high precision and accuracy. It involves using computer-aided design (CAD) software to create a digital model of the desired structure, which is then translated into a physical object using a 3D printer. The printer deposits successive layers of bioink, which contains living cells and other biomaterials, to create a 3D structure that mimics the native tissue. One of the most promising applications of 3D bioprinting is developing drug delivery systems (DDSs) to administer several active substances, such as growth factors, proteins, and drug molecules. DDSs are designed to release drugs at a controlled rate over an extended period, which can improve therapeutic efficacy and reduce side effects. Chitosan-based implants have emerged as a promising candidate for DDSs due to their attractive properties, such as biodegradability, biocompatibility, low cost, and non-immunogenicity. 3D bioprinting technology has emerged as a powerful tool for developing simultaneously controlled DDSs for administering several active substances. The rationale behind integrating 3D printing technology with chitosan-based scaffolds for drug delivery lies in the ability to produce customized, biocompatible, and precisely designed systems that enable targeted and controlled drug release. This novel methodology shows potential for advancing individualized healthcare, regenerative treatments, and the creation of cutting-edge drug delivery systems. This review highlights the potential applications of 3D bioprinting technology for preparing chitosan-based implants for drug delivery.

During the last two decades, non-conventional solvents, especially various ionic liquids, have been utilized as efficient reaction media as they can play a dual role as solvents and promoters. The use of ionic liquids as a medium increases the efficiency of the reactions due to their inherent features like high thermal stability, ability to act as a catalyst, non-volatility, high polarity, reusability, ability to dissolve a large number of organic and inorganic compounds, etc. Under this direction, various structurally diverse ionic liquids have been employed as efficient reaction media for various organic transformations. On the other hand, among many other important synthetic scaffolds, during the last two decades, the synthesis of pyrans, pyran-annulated heterocyclic scaffolds, and spiropyrans have gained huge attention as they possess a wide range of significant biological efficacies, which include antibacterial, anticancer, antimycobacterial, antioxidant, xanthine oxidase inhibitory, etc. activities. Almost every day, many new methods are being added to the literature related to synthesizing pyrans, pyran- annulated heterocyclic scaffolds, and spiropyrans. Among many other alternatives, various ionic liquids have also played an efficient role as promoters for synthesizing structurally diverse pyrans, pyran-annulated heterocyclic scaffolds, and spiropyrans. In this review, we have summarized a large number of literature reported during the last two decades related to the ionic liquid-promoted synthesis of pyrans, pyran-annulated heterocyclic scaffolds, and spiropyran derivatives.

The quinoline derivatives arouse interest due to their broad spectrum of activity. The phosphorus compounds under investigation, quinolinylphosphonic and -phosphinic acids and aminophenylphosphonic and -phosphinic acids, possess potent bioactive properties, mimicking amino acids, phosphate esters, anhydrides, or carboxylate groups in enzymes. Despite its potential value, there is no reported example of quinolinylphosphonic or - phosphinic acids with phosphonic or phosphinic functional groups connected directly to the benzene ring in quinoline constitution. The selected quinoline derivatives have been synthesized by adopting the Skraup-Doebner-Von Miller reaction. To this end, the syntheses of aminophenylphosphonic and -phosphinic acids were conducted and afforded the target products with high yield. All structures have been proven by the combination of NMR, IR, MS, and HRMS techniques and were rationalized based on DFT calculation. The structures of triphenylphosphane oxide (TPO), diphenylphosphosphinic acid (1c), (tert-butyl)phenylphosphinic acid (1d) and bis(3-nitrophenyl)phosphinic acid (2c) were determined by single-crystal X-ray diffraction measurements. The Hirshfeld surface analyses for 1c, 1d and 2c were performed to analyze the intermolecular interactions in their crystal structures. According to our findings, the presence of numerous intermolecular PO•••H, NO•••H, and CH•••O contacts stabilizes the crystal structures. The NO•••H interactions manifest in the IR spectrum of 2c crystal as a narrow band with a maximum at 3088 cm^-1. The PO•••H intermolecular interactions are attributed to a weak experimental band at 1288 cm^-1.

Sulfonamide, imidazole, and triazole chemical nuclei possess good antimicrobial potential. This study aimed to amalgamate sulfonamide, imidazole, and triazole moieties in a single molecular framework with the intent of improving their antimicrobial activities. The objective of this study was the synthesis of conjugates containing sulfonamide and azole moieties along with in vitro and in silico evaluation as antimicrobial candidates. A series of sulfonamide-modified azoles (7a-r) was synthesized by multicomponent condensation of 1,2-dicarbonyl compounds, ammonium acetate and aryl-substituted aldehydes in glacial acetic acid. The structure of synthesized molecules was elucidated with the help of various spectroscopic techniques, such as FTIR, NMR, and HRMS. The target molecules were tested for in vitro antimicrobial potency against four bacterial strains and two fungal strains. Molecules 7c (MIC 0.0188 μmol/mL), 7f (MIC 0.0170 μmol/mL) and 7i (MIC 0.0181 μmol/mL) were most active against S. aureus and C. albicans. Against E. coli, molecules 7d (MIC 0.0179 μmol/mL), 7f (MIC 0.0170 μmol/mL) and 7i (MIC 0.0181 μmol/mL) were found to be highly active. Moreover, the binding conformations were investigated by in silico molecular docking, and QTAIM (Quantitative theory of atoms in the molecule) analysis was also performed. Molecular properties, such as the heat of formation, HOMO energy, LUMO energy and COSMO volume, were found to be in direct correlation with the antimicrobial potency of molecules 7c, 7f and 7i against S. aureus and C. albicans. All the synthesized molecules were more potent than clinically approved sulfonamides, namely sulfadiazine and sulfabenzamide.