Chalcogenium-AZT Derivatives: A Plausible Strategy To Tackle The RT-Inhibitors-Related Oxidative Stress While Maintaining Their Anti- HIV Properties.

BACKGROUND: This study presents the synthesis and multi-target behavior of the new 5'-hydroxy-3-(chalcogenyl-triazoyl)-thymidine and the biological evaluation of these compounds as antioxidant and anti-HIV agents. OBJECTIVE: Antiretroviral therapy induces oxidative stress. Based on this, this manuscript's main objective is to prepare compounds that combine anti-HIV and antioxidant activities. METHODS: The compounds were prepared from commercially available AZT through a copper-catalyzed Huisgen 1,3-dipolar cycloaddition exploiting the AZT azide group and chalcogenyl alkynes. RESULTS: The chalcogenium-AZT derivatives were obtained in good yields via click chemistry. The compounds evaluated showed antioxidant and anti-HIV activity. Additionally, in vivo toxicity of this class of compounds was also evaluated. The representative nucleoside did not change the survival, behavior, biochemical hepatic, or renal markers compared to the control mice. CONCLUSION: Data suggest the feasibility of modifying the AZT nucleus with simple organohalogen fragments, exploring the reactivity of the azide group via 1,3-dipolar Huisgen cycloaddition reaction. The design of these new compounds showed the initially desired biological activities.

Decarboxylative ring-opening of 2-oxazolidinones: a facile and modular synthesis of ß-chalcogen amines.

We report herein the synthesis of primary and secondary ß-chalcogen amines through the regioselective ring-opening reaction of non-activated 2-oxazolidinones promoted by in situ generated chalcogenolate anions. The developed one-step protocol enabled the preparation of ß-selenoamines, ß-telluroamines and ß-thioamines with appreciable structural diversity and in yields of up to 95%.

Synthesis of 4-Arylselanyl-1H-1,2,3-triazoles from Selenium-Containing Carbinols.

In this work, we present a simple way to achieve 4-arylselanyl-1H-1,2,3-triazoles from selenium-containing carbinols in a one-pot strategy. The selenium-containing carbinols were used as starting materials to produce a range of selanyl-triazoles in moderate to good yields, including a quinoline and Zidovudine derivatives. One-pot protocols are crucial to the current concerns about waste production and solvent consumption, avoiding the isolation and purification steps of the reactive terminal selanylalkynes. We could also isolate an interesting and unprecedented by-product with one alkynylselenium moiety connected to the triazole.

Fluorescent Benzoselenadiazoles: Synthesis, Characterization, and Quantification of Intracellular Lipid Droplets and Multicellular Model Staining.

In this work, we described the synthesis of 10 new fluorescent 2,1,3-benzoselenadiazole small-molecule derivatives and their chemical- and photocharacterizations. The new derivatives could, for the first time, be successfully applied as selective live cell imaging probes (at nanomolar concentrations) and stained lipid-based structures preferentially. Density functional theory (DFT) calculations were used to help in understanding the photophysical data and the intramolecular charge-transfer (ICT) processes of the synthesized dyes. Some derivatives showed impressive cellular responses, allowing them to be tested as probes in a complex multicellular model (i.e., Caenorhabditis elegans). When compared with the commercially available dye, the new fluorescent compounds showed far better results both at the cellular level and inside the live worm. Inside the multicellular complex model, the tested probes also showed selectivity, a feature not observed when the commercial dye was used to carry out the bioimaging experiments.

Transition metal catalysed direct selanylation of arenes and heteroarenes.

Transition metal catalysed C-H functionalization has reached an exciting level of sophistication, and, today, it represents a paradigm shift from the standard logic of synthetic chemistry. The direct conversion of C-H bonds into C-heteroatoms remains, however, a critical challenge. Nowadays, there is a great demand in general synthetic chemistry in, for example, the materials science for the development of straightforward C-Se bond formation, in order to fulfil the practical requirements. In this sense, this review summarizes recent outstanding advances in the C-Se bond formation through transition metal-catalysed direct selanylation, providing new insights into their mechanistic aspects and disclosing effective synthetic routes with high atom economy. In addition, this review intends to show the growing opportunities to construct complex chemical scaffolds containing selenium atoms.