Alzheimer's Disease (AD), first reported in 1906, nowadays is the most common cause of dementia amongst older people. According to the leading hypothesis, described in 1992 in Science and called the amyloid cascade hypothesis, overproduction of β-amyloid peptides (Aβ) are related to AD development. These peptides have three important features related to AD pathology: first of all, they aggregate very fast. For this reason, an abnormal increase of Aβ accumulation leads to their aggregation in the brain, forming oligomers and then amyloid plaques, which ultimately provokes neuronal dysfunction and the death of neurons. Secondly, they bind copper(II) ions, which accelerates the aggregation process. Finally, the Cu(II)-Aβ complexes catalyse the production of Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS) contributing to oxidative stress. For the aforementioned reasons, there is great interest in the development of new therapeutic substances whose mechanism of action is based on two strategies: the removal of amyloid beta deposits from the brain or the extraction of Cu(II) ions. In 2021, the Aducanumab antibody directed against Aβ aggregates received its first approval in the USA for the treatment of AD. Unfortunately, this drug is not suitable for all patients. Therefore, specific copper chelators are investigated as a good alternative. Up to now, chelators such as clioquinol (CQ) and PBT2 have failed in clinical trials due to the formation of redox-active ternary complexes with Cu(II)-Aβ. Presently, a new promising prototype ligand series, named TDMQ (tetradendate monoquinolines), is being studied intensively. TDMQ ligands have an 8-aminoquinoline motif with a bidentate amine side chain attached to the quinoline moiety. This molecule structure provides the square planar tetradentate coordination sphere preferred for effective chelation and selectivity for copper(II) ions. TDMQ molecules efficiently extract Cu(II) from Cu(II)-Aβ complexes, creating new 1:1 metal:ligand complexes Cu(II)-TDMQ (Scheme 1). Of all TDMQ ligands, TDMQ20 exhibits the highest affinity constant with Cu(II) ions. The use of TDMQ20 exhibits many advantages: for example, it does not disturb the activity of metalloenzymes such as Cu-Zn-SOD, tyrosinase or metal-containing cofactors like vitamin B12. Also, the biomimetic oxidation of TDMQ20 leads to products fully soluble under aqueous experimental conditions which, therefore, probably do not accumulate in human body tissues. The results of preclinical studies carried out in mice also showed the highest effectiveness of TDMQ20 in reducing oxidative stress. For all these reasons, TDMQ20 could be considered as a good drug candidate for AD treatment.