Minor Modifications to the Ligands Surrounding a Ruthenium Complex Lead to Major Differences in the Way in which they Catalyse the Hydrogenation of Arenes

Abstract

The hydrogenation of benzene and other arenes under aqueous-organic biphasic conditions is evaluated using the ruthenium complexes Ru(h . The active catalysts formed during the hydrogenations correspond to a trinuclear cluster, a colloid and a mononuclear complex, respectively.

Incorporating ruthenium into advanced drug delivery carriers – an innovative generation of chemotherapeutics

“…Ruthenium‐Arene‐PTA (RAPTA) compounds, characterized by Dyson and coworkers, contain the Ru II centre, two labile chlorido ligands available for aquation, a lipophilic arene ligand and the hydrophilic phosphine ligand 1,3,5‐triaza‐7‐phosphaadamantane (PTA). They are weakly cytotoxic to tumour cells in vitro , interacting with both DNA and proteins, display antimicrobial activity, and typically are not toxic to healthy cells, even after prolonged exposure .…”

Diffusion NMR Studies on the Self-Aggregation of Ru-Arene CAP Complexes: Evidence for the Formation of H-Bonded Dicationic Species in Acetonitrile

“…3−5 Among the many stabilizing ligands, monodentate ligands containing P,N cages have been shown to give the complexes peculiar and tunable properties in terms of stability, reactivity, and solubility. 6 A well-known class of ruthenium(II) arene derivatives with these requisites, better known as RAPTA-type complexes (Chart 1), 7 is obtained in the presence of the cagelike aminophosphine PTA (1,3,5-triaza-7-phosphaadaman- tane), 8,9 and some of the corresponding complexes described in the literature were found to be active water-soluble catalysts in hydrogenation reactions 10 and very efficient anticancer agents. 11−13 Recently, some of us reported the synthesis of ruthenium(II) p-cymene complexes bearing a higher homologue of PTA, namely 1,4,7-triaza-9-phosphatricyclo[5.3.2.1]tridecane ligand (CAP) (Chart 1), which showed interesting activities in homogeneous catalytic transfer hydrogenations 14 and in cytotoxicity studies against selected cancer cell lines.…”

“…Organometallic ruthenium complexes have attracted the attention of many research groups due to their great versatility and application in different fields such as catalysis, materials science, and biochemistry. , In particular, a widely used class of complexes is characterized by the presence of an η 6 metal-coordinated arene moiety and a piano-stool geometry, which endows the metal center with a wide range of applications. − Among the many stabilizing ligands, monodentate ligands containing P,N cages have been shown to give the complexes peculiar and tunable properties in terms of stability, reactivity, and solubility . A well-known class of ruthenium­(II) arene derivatives with these requisites, better known as RAPTA-type complexes (Chart ), is obtained in the presence of the cagelike aminophosphine PTA (1,3,5-triaza-7-phosphaadamantane), , and some of the corresponding complexes described in the literature were found to be active water-soluble catalysts in hydrogenation reactions and very efficient anticancer agents. − …”

Ruthenium(II)-Arene Complexes of the Water-Soluble Ligand CAP as Catalysts for Homogeneous Transfer Hydrogenations in Aqueous Phase

“…Another class of catalytically active compounds is represented by [RuCl2(η 6 -p-cymene)(PTA)] (RAPTA-C) and [RuCl(η 6 -p-cymene)(PTA)2](BF4), which were shown to be active catalysts for the full hydrogenation of various substituted arenes into the corresponding cyclohexanes under biphasic conditions [20]. Some Ru(II) complexes bearing 'upper rim' PTA derivatives-i.e., pending arms on the C atom adjacent to the P donor ( Figure 1)-were also tested in catalytic hydrogenation of acetophenone giving good conversions even at room temperature using protocols based on the presence of both H2 gas and t BuOK/ i PrOH [21].…”

“…These compounds were tested in vitro for their cytotoxic activity against selected cancer cell lines with good results [22]. [20]. Some Ru(II) complexes bearing 'upper rim' PTA derivatives-i.e., pending arms on the C atom adjacent to the P donor ( Figure 1)-were also tested in catalytic hydrogenation of acetophenone giving good conversions even at room temperature using protocols based on the presence of both H2 gas and t BuOK/ i PrOH [21].…”