Novel Tertiary Amine‐Functionalized Selenium Heterocycles: Synthesis, Antibacterial, and Antioxidant Investigations

ABSTRACT A novel three‐series of selenium‐containing heterocycles ( SeCHet ) incorporating tertiary amine functionalities, namely N ‐alkyl selenopyridines ( 5a–e and 6a–c ) and N ‐alkyl selenopheno[2,3‐ b ]pyridines 7a–d , were successfully synthesized through the reaction of selenium‐chloroacetamide scaffold derivatives 3a and 3b with various secondary amines. These compounds were designed based on the well‐established biological importance of both selenium‐based heterocyclic compounds and amine‐containing molecules in biological activities, particularly their antioxidant and antibacterial properties against selected Gram‐positive and Gram‐negative bacterial strains. Several compounds exhibited promising biological activity, with derivatives containing the diethylamino and piperidine moieties showing enhanced antibacterial effects, particularly against Bacillus cereus , with an inhibition percentage more than the standard drug (ciprofloxacin). In addition, notable antioxidant activity was observed for selected compounds; the activity of compound 5b was comparable to vitamin C, with an inhibition percentage similar to vitamin C, 74%. Derivatives 6a and 7a showed the highest antioxidant performance, with inhibition rates of 72% and 67%, respectively, indicating the potential of these structures as biologically active agents. Overall, the obtained results highlight the significance of incorporating tertiary amine and selenopyridine functionalities in the development of new compounds with potential pharmaceutical applications.