Pyrazolylboratozinc Complexes of Nucleosides and Nucleoside Analogues

Abstract

Attachment of deprotonated nucleosides or of alkylated nucleobases, as their analogues, to zinc was achieved by condensation reactions between TpZn‐OH complexes and nucleobase derivatives. Pyrazolylboratozinc complexes with derivatives of uracil, thymine, guanine, xanthine and hypoxanthine were obtained and characterized by structure determination. In the uracil, thymine, guanine and hypoxanthine derivatives, zinc is bound to the nitrogen atom which bears the proton in the nucleoside. In the xanthine derivatives all three possible bonding modes are realized. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Insertion Reactions of Heterocumulenes into Zn−C Bonds: Synthesis and Structural Characterization of Multinuclear Zinc Amidate Complexes

“…Therefore, 2 represents the first structurally characterized zinc complex exhibiting an N,O-chelating amidate ligand. A comparable structural motif was previously observed in zinc pyridonate and 9-isobutylguanidinate complexes . The Zn atoms in 1 and 2 adopt tetrahedral coordination spheres, and the Zn−C bond lengths as observed in 1 (mean value 1.974 Å) and 2 (mean value 1.957 Å) are comparable and are in the typical range reported for Zn−Me groups.…”

A Sterically Hindered N,N,O Tripod Ligand and Its Zinc Complex Chemistry

“…The main indicator is the ν(CO) absorption in the IR at 1644 cm -1 which exactly corresponds to that of the pyrazolylborate complex Tp Cum,Me Zn-1-methyluracilate which we have structurally characterized. 51 o-Formylphenolate (the anion of salicylic aldehyde) and o-hydroxymethylphenolate were applied with the clear expectation that they might act as bidentate ligands. Their formyl and hydroxymethyl groups represent the oxidized and reduced forms of the substrates (aldehyde/alcohol) which are interconverted by the zinc-containing alcoholdehydrogenase enzymes.…”

Transition Metal Ion Complexes of N-alkylguanines

“…Badura and Vahrenkamp [67] have prepared pyrazolylboratozinc complexes of nucleobases to gain insight into the interaction of these complexes with nucleic acids, Scheme (18). Thus, compound (123) was treated with 9-isobutylguanine to afford the two isomers (124a) and (124b) of the corresponding guaninyl adduct.…”

“…Alberto et al [45] have prepared and characterized by X-ray crystallography the cis-bispurine complex cis-[Ru II (bpy) 2 (Hm 9 gua) 2 ](CF 3 SO 3 ) 2 (67 · (CF 3 SO 3 ) 2 ). Complex (67) was made by the thermal reaction of complex cis-[Ru II (bpy) 2 (OSO 2 CF 3 ) 2 ] (66) with 9-methylguanine, Scheme (11). Previously, only the monoadduct, containing a single 9-methylguanine residue, had been obtained [44,48].…”