Efficient synthesis and free-radical scavenging capacity of new 2,4-substituted tetrahydroquinolines prepared via BiCl3-catalyzed three-component Povarov reaction, using N-vinylamides

• Published in: Molecular diversity 2011-11, Vol.15 (4), p.1007-1016
• Main Authors: Kouznetsov, Vladimir V., Gómez, Carlos M. Meléndez, Parada, Luz K. Luna, Bermudez, John H., Méndez, Leonor Y. Vargas, Acevedo, Amner Muñoz
• Format: Article
• Language: English
• Subjects: Amides - chemistry; Biochemistry; Biomedical and Life Sciences; Bismuth - chemistry; Catalysis; Chemistry Techniques, Synthetic - methods; Chlorides - chemistry; Free Radical Scavengers - chemical synthesis; Free Radical Scavengers - chemistry; Full-Length Paper; Life Sciences; Organic Chemistry; Pharmacy; Polymer Sciences; Quinolines - chemical synthesis; Quinolines - chemistry
• ISSN: 1381-1991; 1573-501X
• DOI: 10.1007/s11030-011-9330-5

Efficient synthesis of new structurally different 2-(het)aryl-4-amidyl-substituted tetrahydroquinolines 8–29 is reported. The synthesis based on BiCl 3 -catalyzed three-component Povarov reaction between anilines, (het)aryl aldehydes and enamides offers a fast, safe, and cheap way for efficient tetrahydroquinoline libraries construction. Using N -vinylamides ( N -vinylpyrrolidin-2-one and N -vinylacetamide) in this reaction, it was possible to obtain two series of different cis tetrahydroquinolines with antioxidant properties. Among 14 tested compounds, 7 tetrahydroquinolines revealed a prominent anti-radical capacity, equal or higher than that of the commercial antioxidants. Being the most active molecule, the N -[2-(α-furanyl)-6-methoxy-1,2,3,4-tetrahydroquinolin-4-yl] acetamide 21 was ca. 2.2-fold more potent than the well-known antioxidant, vitamin E (α-tocopherol).