PTA-based chemistry: a versatile platform for coordination chemistry and catalysis in water

Among the possible green solvents that can be used in chemistry to replace dangerous and toxic organic counterparts, water is highly desired due to its abundance and properties. In order to bring about catalytic reactions in water though, it is often necessary to modify the ancillary ligands of a known, efficient catalyst to obtain water solubility. In Florence, we have focused our attention on the synthesis, structural modification and use of the small cone-angle, cage aminophosphine 1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane (PTA). In this lecture, the main results on the coordination chemistry of PTA and its derivatives, and the use in water phase or biphasic water/organic solvent catalytic reactions, will be reviewed. More recently, we studied the properties of a higher homologue of PTA, the more flexible analogue 1,4,7-triaza-9-phosphatricyclo[5.3.2.1]tridecane (CAP), and obtained novel ruthenium(II)-arenecomplexes, that were applied for homogenous transfer hydrogenation of C=C and C=N bonds. Some of these results will also be here discussed.We thank all colleagues who collaborated with us on this research 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).