a b s t r a c t The neutral phosphorus nucleophiles such as R 2 P(@Y)M [1a–f, Y@O or lone pair; R = Ph, tBu, OCH 2 C(CH 3) 2 CH 2 O, Pr i O, EtO or MeO; M = H or SiMe 3 ] allowed the radical addition to 2-methyl-5,8-dioxo-5,8-dihydro-quinoline-7-amine (2a) and N-(2-methyl-5,8-dioxo-5,8-dihydroquinolin-7-yl)acetamide (2b) giving exclusively O-phosphorylated products, i.e.: 7-acetylamino-5-hydroxy-2-methylquinolin-8-yl diph-enylphosphinate (3a), 7-acetylamino-5-hydroxy-2-methylquinolin-8-yl-tbutylphenylphosphinate (3b), 7-acetylamino-5-hydroxy-2-methylquinolin-8-yl diisopropyl phosphate (3c), 7-acetylamino-5-hydroxy-2-methylquinolin-8-yl diethyl phosphate (3d), N-{8-[(5,5-dimethyl-2-oxido-1,3,2-dioxaphosphinan-2-yl)oxy]-5-hydroxy-2-methylquinolin-7-yl}acetamide (3e), 7-amino-5-hydroxy-2-methylquinolin-8-yl dimethyl phosphate (3f) and 7-amino-5-hydroxy-2-methylquinolin-8-yl-tbutylphenylphosphinate (3g), respectively, with high yield. All products were quantitatively prepared and characterized by microanaly-sis, and multinuclear NMR spectroscopy. Seven of them, i.e.: 2a, 2b, 3a, 3b, 3d, 3e and 3g have been char-acterized by single crystal X-ray diffraction method. The geometries of the studied compounds were optimized in singlet states using the density functional theory (DFT) method with B3LYP functional. The redox properties of 2a and 2b have been studied using cyclic voltammetry. The reduction corresponds to the electrochemical behaviour of naturally occurring quinones.