Preparation of New Bis(8‐aminoquinoline) Ligands and Comparison with Bis(8‐hydroxyquinoline) Ligands on Their Ability to Chelate Cu^II and Zn^II

Abstract

New bis(8-aminoquinoline) ligands linked on the C2 carbon atom of both quinolines have been prepared. When the linker includes a one-atom amino group, the corresponding compound is an excellent chelator of Cu II ions and forms a mononuclear species with high metal ion selectivity relative to Zn II chelation. This selectivity for Cu II ions was not observed for a bis(8-hydroxyquinoline) analogue. The chelating properties of these ligands are compared to those of the bis(8-aminoquinoline) ligands with different linkers between

Catechol‐Based Ligands as Potential Metal Chelators Inhibiting Redox Activity in Alzheimer's Disease

“…Complexation of copper(II) by ligands 1 – 3 was achieved by addition of aliquots of CuCl 2 up to 20 equiv. with respect to the ligand, and was monitored by UV/Vis spectroscopy, as previously reported . The same behavior was observed for ligands 1 – 3 .…”

“…These catechol-based ligands exhibit high specific affinities for Cu II and Fe III , and a lower affinity for Zn II , which indicates that they may interact with redox metal ions without disturbing the structural and dynamic role of zinc chelation in many proteins. These ligands inhibit the reduction of dioxygen induced by Cu II -A [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] , and this suggests that they may be able to efficiently reduce the oxidative stress induced by metalloaded amyloids in the AD brain.…”

Preparation of Tetradentate Copper Chelators as Potential Anti‐Alzheimer Agents

“…With as hort proximal chain (n = 1, TDMQ5 and 19), the pK a of the proximal nitrogenw as 8.5-8.7, while it wasi nt he range of The ability of TDMQl igands to chelate metal ions Cu II and Zn II was monitored by UV/Vis titrationo ft he aminoquinoline ring (230-400nm), as previously reported. [16,24,25] Spectralm odifications upon addition of aliquots of concentrated aqueous solutions of Cu 2 + or Zn 2 + salts were recorded and considered significant forthe metal complexation by the TDMQ ligand.…”

Synthesis and Characterization of Half‐Sandwich Ruthenium Complexes Containing Aromatic Sulfonamides Bearing Pyr­id­inyl Rings: Catalysts for Transfer Hydrogenation of Acetophenone Derivatives

“…[12][13][14][15][16] Also, catalysis and the molecular structural properties of sulfonamides have recently been studied in detail by our research team. [17a-17d] Ketone TH catalyzed by Ru II complexes containing Ndonor ligands has attracted increasing attention [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] since the success of Noyori's work using 1,2-diamine ligands. [33] Several diamine ligand modifications have been explored aimed at developing catalysts with increased activity.…”