735271-75-7Relevant academic research and scientific papers
Synthesis of Oxorhenium(V) and Oxotechnetium(V) Complexes That Bind to Amyloid-β Plaques
Hayne, David J.,White, Jonathan M.,McLean, Catriona A.,Villemagne, Victor L.,Barnham, Kevin J.,Donnelly, Paul S.
, p. 7944 - 7953 (2016/08/24)
Alzheimer's disease is characterized by the presence of amyloid plaques in the brain. The primary constituents of the plaques are aggregated forms of the amyloid-β (Aβ) peptide. With the goal of preparing technetium-99m complexes that bind to Aβ plaques with the potential to be diagnostic imaging agents for Alzheimer's disease, new tetradentate ligands capable of forming neutral and lipophilic complexes with oxotechentium(V) and oxorhenium(V) were prepared. Nonradioactive isotopes of technetium are not available so rhenium was used as a surrogate for exploratory chemistry. Two planar tetradentate N3O ligands were prepared that form charge-neutral complexes with oxorhenium(v) as well as a ligand featuring a styrylpyridyl functional group designed to bind to Aβ plaques. All three ligands formed complexes with oxorhenium(V), and each complex was characterized by NMR spectroscopy, mass spectrometry, and X-ray crystallography. The oxorhenium(V) complex with a styrylpyridyl functional group binds to Aβ plaques present in post-mortem human brain tissue. The chemistry was extrapolated to technetium-99m at the tracer level for two of the ligands. The resulting oxotechnetium(V) complexes were sufficiently lipophilic and charge-neutral to suggest that they have the potential to cross the blood-brain barrier but exhibited modest stability with respect to exchange with histidine. The chemistry presented here identifies a strategy to integrate styrylpyridyl functional groups into tetradentate ligands capable of forming complexes with [M=O]3+ cores (M = Re or Tc).
A convenient synthesis of nickel(II) and cobalt(II) complexes of unsymmetrical salen-type ligands and their application as catalysts for the oxidation of 2,6-dimethylphenol and 1,5-dihydroxynaphthalene by molecular oxygen
Adam, Waldemar,Saha-Moeller, Chantu R.,Ganeshpure, Pralhad A.
, p. 56 - 62 (2007/10/03)
Salen-type ligands 1-4 have been synthesized in high yields, from which the nickel(II) complexes 9-11 and the cobalt(II) complexes 12 and 13 have been prepared and characterized. The complexes have been assessed for their ability to activate molecular oxygen in the catalytic oxidation of phenols, namely, 2,6-dimethylphenol and 1,5-dihydroxynaphthalene. The nickel complexes 9-11 are inactive in the oxidation of the phenols but the cobalt complexes 12 and 13 show high catalytic activity.
