Structural, spectroscopic and electrochemical characterizations of new 2,5-bis(phosphoranyl)-3,6-diaminoquinones

Abstract

Cu(II) catalyzed open air reactions of 2,5-bis(-P(O)R₂))-3,6-dichloro-hydroquinones (R = Ph or iPr) with selected primary amines or ammonia proceeded with oxidation of the hydroquinone ring and substitution of chlorines by the amino groups. The products of these reactions were 2,5-bis(-P(O)R₂))-3,6-di(-NHR’)-quinones (1a, R = Ph, R′ = Cy; 1b, R = iPr, R′ = Cy; 2a, R = Ph, R′ = –CH(CH₂OH)₂; 2b, R = iPr, R′ = –CH(CH₂OH)₂; 3a, R = Ph, R′ = –CH₂CH(OH)CH₂OH; 3b, R = iPr, R′ = CH₂CH(OH)CH₂OH; 4a (R = Ph, R′ = H; 4b, R = iPr, R′ = H). They were isolated as bright orange or yellow solids in moderate/good yields. The compounds were characterized by multinuclear (¹H,¹³C,³¹P) NMR, FT-IR, UV–Vis, high resolution mass-spectrometry, and cyclic voltammetry. Compounds 1b, 2a, 3a and 4a,b were also characterized by single crystal X-ray diffraction methods.