Vanessa Nascimento

Quinoline-based chromophores are of great interest in medicinal chemistry due to their ability to bind DNA, modulate key biochemical pathways, and serve as fluorescent probes for molecular recognition and therapeutic applications. The incorporation of chalcogen atoms further broadens the functional scope of these systems; S and Se can modulate electronic distribution, polarizability, and photophysical behavior through chalcogen bonding and heavy-atom effects. Building on these properties, we rationally designed and synthesized 11 quinoline- and organochalcogen-based derivatives, achieving yields of 10–75% through a simple and efficient method involving the introduction of various electron-donating and electron-withdrawing substituents, as well as different chalcogen atoms (Se and S), including one Se derivative in a higher oxidation state. These compounds were subjected to systematic photophysical, electrochemical, reactive oxygen species generation, and DNA-binding studies. The fluorescence analyses revealed intense UV absorption and low to moderate fluorescence quantum yields, both of which were by the nature of the chalcogen atom. Selenium derivatives displayed reduced emission and were more susceptible to oxidation, whereas selenoxide exhibited a larger electrochemical band gap. The data indicated a preference for minor groove DNA binding, with the π-extended derivative showing the highest affinity. This integrated approach highlights the potential of quinoline-organochalcogen hybrids as multifunctional platforms for advanced applications in photophysics, electrochemistry, and DNA-targeted therapeutics.

The benzopyran scaffold is a versatile family of heterocycles found in a wide range of bioactive natural products and functional molecules. In response to increasing environmental and regulatory demands, developing synthetic strategies focused on sustainability and low‐impact conditions has become a central focus in modern heterocyclic chemistry. Therefore, this review provides a comprehensive and critical analysis of low‐impact methods reported over the past 8 years for constructing benzopyran‐derived structures, including coumarins, flavones, chromones, chromenes, and chromanes. We systematically integrated both enabling technologies (e.g., microwave irradiation, visible‐light photocatalysis, continuous‐flow systems, and ultrasound activation) and chemical strategies involving biocatalysis, multicomponent reactions, recyclable heterogeneous catalysis, and alternative solvents, including deep eutectic solvents and ionic liquids. Advances in selectivity, efficiency, and catalyst reusability are highlighted, as are certain limitations. By contextualizing these methods within the various benzopyran scaffolds, this review provides an important foundation for the rational integration of sustainable tools in benzopyran synthesis and highlights perspectives for future research, thereby enhancing their industrial and pharmaceutical relevance.

Visible-light-mediated multicomponent reactions offer a simple and efficient approach for constructing functionalized heterocycles. Herein, we report a photocatalyst-free, iodine-mediated multicomponent protocol for the synthesis of 5-amino-4-chalcogenyl-1H-pyrazoles from 3-oxo-3-phenylpropanenitriles, arylhydrazines, and diorganyl dichalcogenides under blue-LED irradiation. The transformation proceeds without transition metals, external oxidants, or additives. Notably, the same optimized reaction conditions enable access to both selenium- and sulfur-containing derivatives without reoptimization, demonstrating the robustness and generality of the methodology. The protocol exhibits a broad substrate scope, enabling the preparation of more than 30 structurally diverse examples and tolerating electron-donating and -withdrawing substituents on both the dichalcogenide and hydrazine partners. Selenium derivatives were obtained in excellent yields, while disulfide analogues were also formed in high yields (up to 98). The synthetic utility was further demonstrated through gram-scale reactions, crossover experiments, and downstream derivatization via the Clauson-Kaas reaction. Control and radical-trapping experiments support a visible light-induced radical pathway, where photoirradiation is responsible for radical generation, enabling the formation of chalcogen-centered species. Overall, this study provides a straightforward strategy for the synthesis of chalcogen-functionalized pyrazoles under mild, metal-free conditions.

Reactive oxygen species (ROS) play essential roles in cellular signaling; however, their dysregulation leads to oxidative stress associated with several chronic diseases. Organoselenium compounds, particularly selenocyanates, exhibit glutathione peroxidase (GPx)-mimetic activity, while the 1,2,4-triazole scaffold is a privileged pharmacophore in medicinal chemistry. In this work, a series of 15 new selenium- and sulfur-cyanides containing 1,2,4-triazole hybrids was designed, synthesized, and evaluated as potential GPx-mimetic antioxidants. The compounds were prepared via a three-step synthetic route and characterized by NMR spectroscopy and high-resolution mass spectrometry. GPx-like activity was assessed using a UV-based assay and supported by density functional theory (DFT) calculations and in silico ADME/Tox analyses. The synthetic approach afforded the target compounds in moderate to excellent yields (37–91%), with several selenium-containing derivatives displaying GPx-like activities up to 3.2-fold higher than the standard. Computational studies revealed correlations between enhanced activity, favorable electronic properties, and drug-like profiles, highlighting chalcogen–triazole hybrids as promising enzyme-mimetic antioxidants.