The Reaction of μ‐η²:η²‐Peroxo‐ and Bis(μ‐oxo)dicopper Complexes with Flavonol

Abstract

The [Cu2(μ‐O)2]2+ and [Cu2(μ‐η2:η2‐O)2]2+ motifs with coordinated N,N,N‐tribenzyl‐1,4,7‐triazacyclononane and N,N,N‐triisopropyl‐1,4,7‐triazacyclononane auxiliary ligands in their reaction with flavonol do not lead to ring scission products of the heterocycle, but the formation of the corresponding (flavonolato)copper(II) complexes [Cu(fla)(Bz‐TAC)]ClO4 and [Cu(fla)(iPr‐TAC)]ClO4. The subsequent oxygenolysis of the coordinated flavonolate ligand leads to O‐benzoylsalicylate at elevated temperature, resulting in the enzyme mimicking products [Cu(O‐bs)(Bz‐TAC)]ClO4, [Cu(O‐bs)(iPr‐TAC)]ClO4) as well as carbon monoxide. The X‐ray structures of [Cu(fla)(Bz‐TAC)]ClO4, [Cu(O‐bs)(Bz‐TAC)]ClO4, and [Cu(O‐bs)(iPr‐TAC)]ClO4) are presented. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

New Chemistry with Anionic NNN Pincer Ligands

“…Copper catecholato and carboxylato complexes of the BPI ligands have been studied as mimics for enzyme active sites [119][120][121]. Catalytic reaction of copper-BPI complex [122] (Fig.…”

(O-Benzoylsalicylato)copper(II) complexes as synthetic enzyme-product models for flavonol 2,4-dioxygenase

“…Two histidines, glutamate, and the O3 atom of the substrate form the equatorial base, and the third histidine is the apical ligand. In the course of model studies of FDO numerous copper complexes of flavonol and O-benzoylsalicylic acid have been prepared and characterized [10][11][12][13][14]. ð1Þ 1387-7003/$ -see front matter Ó…”

“…Two histidines, glutamate, and the O3 atom of the substrate form the equatorial base, and the third histidine is the apical ligand. In the course of model studies of FDO numerous copper complexes of flavonol and O-benzoylsalicylic acid have been prepared and characterized [10][11][12][13][14]. In this communication, we present the synthesis and structural characterization of new (O-benzoylsalicylato)copper(II) complexes with a tetradentate ligand N,Nbis(2-pyridylmethyl)amino-2-ethanoic acid (BPEAH), and tridentate ligands N-benzyl-N,N-bis(2-pyridylmethyl)amine (BnBPA) and N-benzyl-N,N-bis(6-methyl-2-pyridylmethyl)-amine (Bn-6Me 2 BPA) which can serve a good mimics for the enzyme-depside complexes (Fig.…”

Synthesis, structure and catalase mimics of novel homoleptic manganese(II) complexes of 1,3-bis(2′-pyridylimino)isoindoline, Mn(4R-ind)2 (R=H, Me)

“…So considerable efforts were made in order to obtain non-toxic, low molecular weight biomimetic molecules, which are able to catalyze the dismutation of superoxide anion and/or destroy the forming hydrogen peroxide. A variety of low molecular weight complexes of transition metals (Cu, Mn) were prepared and studied as structural and/or functional models for catalases [7][8][9][10][11][12][13].1,3-Bis(2 0 -pyridilimino)isoindolines have been shown to function as neutral, nondeprotonated and also as uninegative chelating ligands capable of complexing a large variety of transition metal ions [14][15][16][17][18][19]. The ligands are capable of occupying three coplanar sites around a metal ion forming either 1:1 or 2:1 (ligand:metal) complexes depending on the coordination number and geometry of the metal ion.…”