title: Ferrocene-modified purines as potential electrochemical markers: synthesis, crystal structures, electrochemistry and cytostatic activity of (ferrocenylethynyl)- and (ferrocenylethyl)purines.
abstract: Palladium-catalyzed Sonogashira cross-coupling reactions of halopurines 9-benzyl-6-chloropurine (2 a), 9-benzyl-8-bromoadenine (2 b), and 9-benzyl-2-chloroadenine (2 c) with ethynylferrocene (1) gave the corresponding (ferrocenylethynyl)purines 3 a-c in moderate to good yields. Catalytic hydrogenation of these alkynes over Pd/C afforded the respective saturated [2-(ferrocenyl)ethyl]purines 4 a-c. The crystal structures 3 a, 3 b, 4 a and 4 b as determined by X-ray diffraction show interesting solid-state interactions, markedly different for purines 3 a and 4 a on one hand and adenines 3 b and 4 b that possess a free amino group on the other. Electrochemistry of electrochemically labelled purines 3 and 4 has been studied by voltammetry and cyclic voltammetry on platinum disc electrode and the experimental oxidation potentials were confirmed and explained by ionization potentials from theoretical DFT calculations. Several compounds of this series exhibited a considerable cytostatic effect.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6, Czech Republic. hocek@uochb.cas.cz
authors.forename: Michal
authors.initials: M
authors.lastname: Hocek
authors.forename: Petr
authors.initials: P
authors.lastname: Stepnicka
authors.forename: Jirí
authors.initials: J
authors.lastname: Ludvík
authors.forename: Ivana
authors.initials: I
authors.lastname: Císarová
authors.forename: Ivan
authors.initials: I
authors.lastname: Votruba
authors.forename: David
authors.initials: D
authors.lastname: Reha
authors.forename: Pavel
authors.initials: P
authors.lastname: Hobza
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D018360:Crystallography, X-Ray; D004354:Drug Screening Assays, Antitumor; D004563:Electrochemistry; D005296:Ferrous Compounds / Q000737:chemistry*; D018922:HL-60 Cells; D006367:HeLa Cells; D006801:Humans; D000075163:Metallocenes; D051379:Mice; D008958:Models, Molecular; D008968:Molecular Conformation; D010165:Palladium / Q000737:chemistry; D011687:Purines / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D005296:Ferrous Compounds; D000075163:Metallocenes; D011687:Purines; D010165:Palladium; C004998:ferrocene