Mini-Reviews in Organic Chemistry - Volume 20, Issue 2, 2023

The pyridazinone derivatives have diverse biological potential and are easily synthesized. Due to this, researchers and chemists have paid attention to the design and development of novel and effective bioactive compounds. The substituted pyridazines have shown a wide range of pharmacological activities, such as analgesic, anti-inflammatory, antibacterial, antifungal, anticonvulsant, antidepressant, antianxiety, antitubercular, anti-malarial, anticancer, anti-HIV, platelet inhibitory, hypotensive, cardiotonic, etc. In the current circumstances, it can be concluded that pyridazinone derivatives have great prospects, which remain to be revealed.

Nowadys, indoor air pollution is harming human health and has become a global problem. Therefore, research on indoor air pollution is necessary. This paper systematically reviews the research progress of indoor air pollution in recent years, mainly including indoor pollutant types and sources, indoor pollutant detection methods and equipment, pollutant release simulation models and quality standards, indoor air treatment technologies, and points out the problems that exist in current researches. Furthermore, it proposes the direction of future research work.

Our environment is in a continuous state of change, which, in turn, demands sustainable, eco-friendly, and safer chemistry techniques. This, in turn, has led to the green chemistry principles coming into the picture in recent years. Over the years, microwave heating has evolved as a green protocol in organic synthesis. The advantages of the safe and environment-friendly MW heating approach include a simple experimental setup, products of high purity with high yields, solvent-free reactions, short reaction times, elimination of the side products, and a decrease in the rate of by-product formation. Heterocycles, especially nitrogen heterocycles, are important not only because they are present in natural products, but because they have widespread applications in pharmaceutical industries as well. These N-heterocycles are part of many biologically active molecules. In the present review, the focus has been laid on the developments in MW-mediated synthesis of biologically important N-heterocycles in the last 2 years (2020-21).

Deep eutectic solvents (DESs) are frequently defined as binary or ternary mixtures of compounds that are able to associate mainly via hydrogen bonds. As the interest in green sustainable solvent’s spread over the entire scientific community, DESs find applications as alternative solvents and/or catalysts for organic transformations. Advantages such as easy reproducible preparation, low cost, environmentally benign nature, wide liquid range, excellent thermal stability, negligible vapour pressure, recyclability, and tunable properties render DESs as a sustainable candidate of catalyst/solvent for futuristic transformations involving multicomponent strategy. In view of the escalating demand for green synthetic approaches, this paper retrospects the advances made in the application of DES in multicomponent reactions since 2018.

Like the well-known sulfa drugs, Sulfonamides are ascribed to a myriad of biological activities, including antioxidant activity. In fact, several tertiary sulfonamides, particularly N, Ndisubstituted analogues, are recognized as antioxidants that can prevent or minimize oxidative damage associated with several oxidative-stress-related diseases. The structural diversity of this class of compounds paved the way for drug discovery programs aimed at finding therapeutic agents. Attributes such as low-cost synthetic procedures, easy accessibility of reagents, and a broad spectrum of biological activities made sulfonamides and derivatives excellent candidates for synthesizing chemical libraries with structural diversity. Sulfonamide-based drugs are most of the sulfur-containing drugs approved by the United States Food and Drug Administration (FDA). Although sulfonamide derivatives have been extensively exploited as antibacterial agents, their therapeutic potential as antioxidants is relatively underexplored despite the prevalence of oxidative stress-mediated diseases and the urgent need for new and more effective antioxidant drugs. Some sulfonamide derivatives were shown to activate the nuclear factor erythroid 2-related factor 2 (Nrf2), the main regulator of the endogenous antioxidant response, a critical process used by cells in response to oxidative stress. The antioxidant role of sulfonamides and derivatives as Nrf2 activators is also reviewed. The antioxidant mechanism of action of sulfonamides has not been fully clarified, but as they have antioxidant properties, it is a subject worthy of in-depth study. The present review is focused on sulfonamides and derivatives as potential antioxidants along the period 2013-2021 and intends to stimulate research in the area.