Water-Soluble Ruthenium Complexes: Catalytic and Medicinal Applications

For several years, our research group has been interested in the synthesis and coordination properties of the neutral water-soluble aminophosphine 1,3,5-triaza-7-phosphadamantane (PTA) and its derivatives. In our laboratories, some PTA transition metal complexes were successfully employed as catalysts for water-phase hydrogenations and hydroformylations, and their use as anticancer agents in medicinal inorganic chemistry was also demonstrated. Some of the most interesting recent results will be briefly highlighted. More recently, a higher homologue of PTA, the more flexible cage aminophosphine 1,4,7-triaza-9-phosphatricyclo[5.3.2.1]tridecane (CAP), was reported in the literature. We obtained and characterized three novel ruthenium(II)-arene half-sandwich complexes bearing CAP as monodentate k-P ligand. Some of the new Ru(II)-CAP complexes (RACAP) showed activity in homogenous C=C and C=N bond catalytic reduction tests. On the other hand, when tested in vitro against selected cancer cell lines, they revealed higher cytotoxicity than the corresponding well-known PTA analogues (RAPTA), still exhibiting a reasonable degree of cancer cell selectivity.We thank all colleagues who collaborated with us on these research lines over the years. The Italian Ministry for Education and Research (MIUR) is kindly acknowledged for partial financial support through Project PRIN 2015 (grant number 20154X9ATP).