Selective Intermolecular C–H Bond Activation: A Straightforward Synthetic Approach to Heteroalkyl Yttrium Complexes Containing a Bis(pyrazolyl)methyl Ligand

Evaluation of heteroscorpionate ligands as scaffolds for the generation of Ruthenium(II) metallodrugs in breast cancer therapy

The modular synthesis of the heteroscorpionate core is explored as a tool for the rapid development of ruthenium-based therapeutic agents. Starting with a series of structurally diverse alcohol-NN ligands, a family of heteroscorpionate-based ruthenium derivatives was synthesized, characterized, and evaluated as an alternative to platinum therapy for breast cancer therapy. In vitro, the antitumoral activity of the novel derivatives was assessed in a series of breast cancer cell lines using UNICAM-1 and cisplatin as metallodrug control. Through this approach, a bimetallic heteroscorpionate-based metallodrug (RUSCO-2) was identified as the lead compound of the series with an IC50 value range as low as 3-5 μM. Notably, RUSCO-2 was found to be highly cytotoxic in TNBC cell lines, suggesting a mode of action independent of the receptor status of the cells. As a proof of concept and taking advantage of the luminescent properties of one of the complexes obtained, uptake was monitored in human breast cancer MCF7 cell lines by fluorescence lifetime imaging microscopy (FLIM) to reveal that the compound is evenly distributed in the cytoplasm and that the incorporation of the heteroscorpionate ligand protects it from aqueous processes, conversion in another entity, or the loss of the chloride group. Finally, ROS studies were conducted, lipophilicity was estimated, the chloride/water exchange was studied, and stability studies in simulated biological media were carried out to propose structure-activity relationships.

Rare-earth complexes supported by an ansa-bis(amidinate) ligand with a rigid o-phenylene linker: synthesis, structure, and catalytic activity for polymerization of cyclic esters

A bis(amidinate) ligand with a rigid o-phenylene linker C₆H₄-1,2-[NC(^tBu)NH(C₆H₅)]₂ (1) was successfully employed for the syntheses of rare-earth amides 2-5 in good yields. The structures of the amides were established by X-ray diffraction analysis and revealed that the ligand framework coordinated to the lanthanide atoms in different fashions depending on the central ion size. Larger lanthanide metal ions La³⁺ and Nd³⁺ prefer to form dinuclear complexes with one linked bis(amidinate) ligand as a bridge, while the smaller sized Y³⁺ and Er³⁺ favor the formation of mononuclear complexes. These complexes exhibited good catalytic activity for ring-opening polymerization of ε-caprolactone and l-lactide and the mononuclear complexes display higher activity.

A family of complexes with N-scorpionate-type and other N-donor ligands obtained in situ from pyrazole derivative and zerovalent cobalt. Physicochemical and cytotoxicity studies

In this paper we described one pot synthetic pathways which generated in situ three complexes which contain three different ligands: N,N,N-tris(3,5-dimethylpyrazolylmethyl)amine (L¹), urotropine (L²) and 3,5-dimethylpyrazole (L³).