New Class of Half-Sandwich Ruthenium(II) Arene Complexes Bearing the Water-Soluble CAP Ligand as an in Vitro Anticancer Agent

Abstract

Ruthenium(II) arene complexes of 1,4,7-triaza-9-phosphatricyclo[5.3.2.1]tridecane (CAP) were obtained. Cytotoxicity studies against cancer cell lines reveal higher activity than the corresponding PTA analogues and, in comparison to the effects on noncancerous cells, the complexes are endowed with a reasonable degree of cancer cell selectivity.

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

“…These compounds were tested in vitro for their cytotoxic activity against selected cancer cell lines with good results [22]. [22].…”

“…Complex 3 was also tested under the same conditions for the C=N bond hydrogenation of selected cyclic imines to produce the corresponding amines. Recently, we reported on the synthesis of a new class of half-sandwich ruthenium arene complexes bearing a higher homologue of PTA, namely 1,4,7-triaza-9-phosphatricyclo[5.3.2.1]tridecane, CAP [22]. As PTA, this compound is a white, air-stable solid under standard conditions, and it is moderately water soluble with S(H 2 O) 25 • C = 20 g L −1 , about one order of magnitude lower than for PTA.…”

“…The two cationic complexes κP-[RuCl(η 6 -p-cymene)(MeCN)(CAP)](PF 6 ) (2) and κP-[RuCl(η 6 -p-cymene)(CAP) 2 ](PF 6 ) (3, Figure 2) were synthesized by chloride abstraction from 1 with TlPF 6 either in the presence of MeCN or a second equivalent of CAP, respectively. 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]. Recently, we reported on the synthesis of a new class of half-sandwich ruthenium arene complexes bearing a higher homologue of PTA, namely 1,4,7-triaza-9-phosphatricyclo[5.3.2.1]tridecane, CAP [22]. As PTA, this compound is a white, air-stable solid under standard conditions, and it is moderately water soluble with S(H2O)25 °C = 20 g L −1 , about one order of magnitude lower than for PTA.…”

“…The two cationic complexes κP-[RuCl(η 6 -p-cymene)(MeCN)(CAP)](PF6) (2) and κP-[RuCl(η 6 -p-cymene)(CAP)2](PF6) (3, Figure 2) were synthesized by chloride abstraction from 1 with TlPF6 either in the presence of MeCN or a second equivalent of CAP, respectively. These compounds were tested in vitro for their cytotoxic activity against selected cancer cell lines with good results [22]. Based on the good catalytic properties shown by Ru(II) arene PTA complexes, we tested complexes 1−3 as catalysts for the reduction of α,β-unsaturated compounds by a mild TH protocol (HCOONa/H2O/MeOH), choosing BZA as model substrate.…”