Photoactivated chemotherapy (PACT) is a novel cancer treatment method that has drawn increasing attention due to its high selectivity and low side effects by spatio-temporal control of irradiation. Compared with photodynamic therapy (PDT), oxygen-independent PACT is more suitable for treating hypoxic tumors. By finely tuning ligand structures and coordination configurations, many Ru(II) complexes can undergo photoinduced ligand dissociation, and the resulting Ru(II) aqua species and/or free ligands may have anticancer activity, showing their potential as PACT agents. In this mini-review, we summarized the progress in Ru(II)-based PACT agents, as well as challenges that researchers in this field still face.

Herein, a series of Ru(arene) complexes, [(η⁶-p-cymene)Ru(bpy)(X)]²⁺ complexes (bpy = 2,2′-bipyridine, X = pyridine, diazine, pyrimidine, and pyrazine) was synthesized, and its photochemical and photobiological properties were carefully compared. It has been found that the basicity of the monodentate ligand has a significant impact on the ligand photodissociation and photobinding DNA abilities of the complexes. A decrease in the basicity of the monodentate ligand leads to a decrease in the electron donating ability of the monodentate ligand; this enhances the photoinduced DNA covalent binding capabilities of 1–4. The CCK8 assay suggests that 4 exhibits the most potent phototoxicity against human lung carcinoma A549 cells among the examined complexes. By changing the basicity of the monodentate ligand, the photobinding abilities increases from the complexes 1 to 4; this provides a good strategy for the development of more efficient metallodrugs with photoactivity.

A new organocatalytic asymmetric domino Michael/O-alkylation reaction of maleimides with γ-halogenated-β-ketoesters catalyzed by simple, cheap, and commercially available quinine is described. The substrates are also commercially available. A variety of new chiral succinimide substituted 3(2H)-furanones were obtained in high yields (up to 94%) and good enantioselectivities (up to 94% ee). The absolute configuration of the new compound 4f was determined by single-crystal X-ray analysis and the proposed reaction pathway is also shown.