title: Solvent-free Povarov reaction for synthesizing ferrocenyl quinolines: antioxidant abilities deriving from ferrocene moiety.
abstract: Twenty-two 2-phenyl-4-ferrocenylquinolines are synthesized by Povarov three-component-reaction (3CR) among the substituted anilines, benzaldehydes, and ferrocenylacetylene with Ce(OTf)3 being catalyst in the absence of solvents. The antioxidative effects of the obtained quinolines are estimated by quenching 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS(+·)), 2,2'-diphenyl-1-picrylhydrazyl (DPPH), and galvinoxyl radicals, and by inhibiting Cu(2+)/glutathione (GSH)-, hydroxyl radical (·OH)-, and 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH)-induced oxidations of DNA. It is found that the ferrocenyl group instead of hydroxyl group generates the antioxidative effect for quinoline to quench radicals and to protect DNA against radical-induced oxidations. The antioxidative effect generated by ferrocenyl group can be further increased by the electron-donating moieties such as furan, -N(CH3)2, -OCH3, and ferrocenyl group, while the electron-withdrawing groups such as -NO2 and -Cl are not beneficial for quinolines to be antioxidants. The ferrocenyl group in quinoline exhibits higher antioxidant activity than hydroxyl group in Trolox.
authors.affiliation: Department of Organic Chemistry, College of Chemistry, Jilin University, Changchun 130021, China.
authors.forename: Gao-Lei
authors.initials: GL
authors.lastname: Xi
authors.affiliation: Department of Organic Chemistry, College of Chemistry, Jilin University, Changchun 130021, China. Electronic address: zaiqun-liu@jlu.edu.cn.
authors.forename: Zai-Qun
authors.initials: ZQ
authors.lastname: Liu
mesh_terms: D000578:Amidines / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000975:Antioxidants / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D004247:DNA / Q000737:chemistry / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005296:Ferrous Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D000075163:Metallocenes; D015394:Molecular Structure; D010084:Oxidation-Reduction / Q000187:drug effects; D015363:Quinolones / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D012997:Solvents; D013329:Structure-Activity Relationship
chemical_list: D000578:Amidines; D000975:Antioxidants; D005296:Ferrous Compounds; D000075163:Metallocenes; D015363:Quinolones; D012997:Solvents; C046728:2,2'-azobis(2-amidinopropane); D004247:DNA; C004998:ferrocene
keywords: Antioxidant; Ferrocene; Free radical; Oxidation of DNA; Quinolines