Ferrocene derivatives with mono‐ (8a–c) and bis‐1,2,3‐triazolyl (9 and 10a–13c) chelating groups were synthesized by regioselective copper(I)‐catalysed 1,3‐dipolar cycloaddition of terminal alkynes with ferrocene azides. Metal complexes of the ligands were prepared with Cu(II) and Zn(II) salts. Crystal structures of ligands 9 and 11a were determined, as well as the structures of complexes [Cu(8a)2](CF3SO3)2 (8aCu) and [Cu(8c)2(CH3OH)2](BF4)2 (8cCu). In addition to NMR and UV–Vis spectroscopy, the metal complexes were characterized by cyclic voltammetry. The cytotoxic effect of ferrocene conjugates and their Zn(II) and Cu(II) complexes was explored, and cell cycle analysis was performed. The complex [Cu(8c)2](CF3SO3)2 showed the most prominent and selective cytotoxicity on cervical carcinoma (HeLa), ovarian cancer (MES‐OV), non‐small cell lung cancer (A549) and breast carcinoma (MDA‐MB‐231) cells. This complex increased cell population in the S and G2/M phase of the cell cycle, which was accompanied by an increase of the cells present in the sub‐G0/G1 fraction.

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Bioorganometallic complexes have attracted considerable interest and have shown promise for potential application in the treatment and diagnosis of cancer, as well as bioimaging agents, some acting as theranostic agents....

Aim: The authors' aim was to improve the application of copper-catalyzed azide-alkyne cycloaddition in the synthesis of hybrids containing biologically significant nucleobases and L-ascorbic acid scaffolds by introducing an environmentally friendly and waste-free ball mill. Results: Two series of hybrids with a purine, pyrrolo[2,3- d]pyrimidine or 5-substituted pyrimidine attached to 2,3-dibenzyl-L-ascorbic acid via a hydroxyethyl- (15a–23a) or ethylidene-1,2,3-triazolyl (15b–23b) bridge were prepared by ball milling and conventional synthesis. The unsaturated 6-chloroadenine L-ascorbic acid derivative 16b can be highlighted as a lead compound and showed strong antiproliferative activity against HepG2 (hepatocellular carcinoma) and SW620 (colorectal adenocarcinoma) cells. Conclusion: Mechanochemical synthesis was superior in terms of sustainability, reaction rate and yield, highlighting the advantageous applications of ball milling over classical reactions.

The synthesis of novel 1,1′‐disubstituted ferrocene conjugates appended with N‐1 and O‐4 alkylated quinolone and quinoline was reported. The target compounds were synthesized employing a liquid‐assisted grinding (LAG) mechanochemical method in copper‐catalyzed azide‐alkyne cycloaddition (CuAAC) to obtain ferrocene−quinoline/quinolone hybrids (5a–5d, 6a–6d, 7a, 7b, 8a, and 8b) in higher yields and shorter reaction time compared to a conventional method, thus proving superiority of mechanochemistry versus conventional synthesis. Bis‐quinoline and bis‐quinolone ferrocene derivatives were evaluated for their antiproliferative effects on five selected tumor and two non‐tumor cell lines. Bis‐6‐methylquinolone–ferrocene conjugate 8b showed the best antiproliferative effect on T‐cell lymphoma (HuT78) cells (IC50 = 14.8 μM) and no cytotoxicity on both non‐tumor MDCK1 and BJ cells. Results obtained after mitochondrial membrane potential (∆Ψm) measurement using flow cytometry showed that compound 8b caused accumulation of HuT78 cells in subG0/G1 phase, disturbance of mitochondrial membrane potential, and apoptosis. The structure of the quinolone and ferrocene hybrid 8b can be further optimized to obtain candidates with better inhibitory effects on HuT78 cells.