The novel nucleobase-ferrocene hybrids: synthesis, structural characterization and electrochemistry

Abstract

U ovom radu opisana je sinteza novih hibrida nukleobaza i ferocena te njihova strukturna karaktrizacija i elektrokemijska ispitivanja. Reakcijom N-alkiliranja uracilnog ili citozinskog prstena sintetizirani su N-1 i/ili N-3 derivati s propargilnim ili butenilnim supstituentima na uracilnom (1, 4, 7, 8 i 19-21) ili citozinskom (15-17) prstenu koji su nadalje uz natrijev azid prevedeni u 4-azidobutenilne derivate 5, 9, 10 i 23. Paladijem kataliziranom Sonogashira-inom reakcijom unakrsnog povezivanja 5-jod-N-1-propargiluracila (1) s etinilferocenom pripravljen je hibrid 5-joduracila i ferocena (2) premošten etinilnom poveznicom u položaju 5 uracila. Hibridi nukleobaza i 4-ferocenil-1,2,3-triazola (3, 6, 11, 12, 14 i 24) pripravljeni su mikrovalovima potpomognutom „klik“ reakcijom 4-azidobutenskih derivata uracila i citozina s etinilferocenom uz Cu katalizator. „Klik“ reakcijom N-propargiliranih derivata nukleobaza (1 i 13) s azidoferocenom uveden je 1,2,3-triazolni prsten u položaj N-1 i N-3 pri čemu su pripravljeni 4-ferocenil–5-joduracil–1,2,3-triazolni hibrid (3) i N-4-benzoilcitozinski hibrid 4-ferocenil-1,2,3-triazola (14). Strukturna karakerizacija hibrida nukleobaza i ferocena provedena je 1H NMR spektroskopijom. Elektrokemijska ispitivanja novosintetiziranih spojeva provedena su cikličkom voltametrijom.This paper describes the synthesis of new nucleobase and ferrocene hybrids and their structural characterization and electrochemistry. N-1 and/or N-3 derivtives with propargyl or butenyl side chain on uracil (1, 4, 7, 8 and 19-21) or cytosine (15-17) ring were synthesized by N-alkylation reaction, which were with sodium azide converted to 4-azidobutenyl derivatives 5, 9, 10 and 23. The palladium catalyzed cross-coupling Sonogashira reaction of 5-iodo-N-1-propargyluracil (1) with ethinylferrocene gave hybrid of 5-iodouracil and ferrocene (2) bridged with the ethynyl linkage at position 5 of uracil. Hybrids of nucleobases and 4-ferrocenyl-1,2,3-triazoles (3, 6, 11, 12, 14 and 24) were prepared by "click" reaction assisted by microwave irradiation of 4-azidobutene derivatives of uracil and cytosine with ethynylferrocene in the presence of Cu catalyst. 1,2,3-triazole ring was introduced in N-1 and N-3 position by "click" reaction of the N-propargylated nucleobase derivatives (1 and 13) with azidoferrocene where 4-ferocenyl-5-ioduracil-1,3,3-triazole hybrid (3) and N-4-benzoylcytosine 4-ferocenyl-1,2,3-triazole hybrid (14) were prepared. Structural characterization of nucleobase and ferrocene hybrides was performed using 1H NMR spectroscopy. Electrochemical evaluation of novel compounds was performed by cyclic voltammetry