Water‐Soluble Palladium(II) Sulfonated Thiosemicarbazone Complexes: Facile Synthesis and Preliminary Catalytic Studies in the Suzuki–Miyaura Cross‐Coupling Reaction in Water

Abstract

A series of mono-and binuclear sulfonated thiosemicarbazone Pd II complexes have been synthesised and characterised using nuclear magnetic resonance spectroscopy, infrared spectroscopy, electrospray ionisation mass spectrometry and elemental analysis. The complexes display excellent water-solubility at room temperature and in addition, 1 H and 31 P{ 1 H} NMR spectroscopic experiments reveal that the mo-

Copper(ii) thiosemicarbazone complexes induce marked ROS accumulation and promote nrf2-mediated antioxidant response in highly resistant breast cancer cells

“…27,28 Second row transition metal complexes Na[Pd(L H )(PPh 3 )] and Na[Pd(L H )PTA] (PTA = 1,3,5triaza-7-phosphaadamantane) were described as efficient catalyst precursors in the Suzuki-Miyaura cross-coupling reactions of phenylboronic acids with aryl halides in aqueous solution. 29 Herein we report on the synthesis of four water-soluble sodium 5-sulfonate-salicylalehyde TSCs with different substituents at the terminal nitrogen atom of the thiosemicarbazide moiety, namely, H, Me, Et, Ph, two of which to our knowledge have never been reported previously, as well as the synthesis of their corresponding copper(II) complexes (Chart 1). We discuss the structural features and electrochemical behaviour of the complexes, as well as their antiproliferative activity in human cancer cell lines (A2780, A2780cis, MCF-7 and MDA-MB-231) relative to their toxicity in healthy embryonic kidney cell line.…”

Thiosemicarbazone Complexes of Transition Metals as Catalysts for Cross-Coupling Reactions

“…For most of the aryl bromides, good conversions were achieved after 2-6 h, while the aryl chorides examined needed an elevated temperature (60 °C) and longer reaction times for comparable results. The complex itself was not soluble in water and was The use of aqueous media for carrying out catalytic reactions has many attractions and in 2017, Matsinha et al reported the synthesis of two water-soluble palladium complexes 20a and 20b containing sulfonated-thiosemicarbazone ligands ( Figure 3) [113]. In both complexes, the ligand is tridentate, and the vacant position is occupied by a tertiary phosphine (PPh3 in 20a and 1,3,5-triaza-7-phosphaadamantane in 20b).…”

“…Although in these studies, possible applications in asymmetric catalysis were not explored, the amenability of thiosemicarbazone ligands to functionalisation with chiral groups could provide a promising avenue for future work. The use of aqueous media for carrying out catalytic reactions has many attractions and in 2017, Matsinha et al reported the synthesis of two water-soluble palladium complexes 20a and 20b containing sulfonated-thiosemicarbazone ligands (Figure 3) [113]. In both complexes, the ligand is tridentate, and the vacant position is occupied by a tertiary phosphine (PPh3 in 20a and 1,3,5-triaza-7-phosphaadamantane in 20b).…”

“…However, the possibility that the catalyst was the precursor to a heterogeneous system which then degraded quickly was ruled out by the authors, since the mercury drop test for such cases failed to affect the catalytic activity to any significant extent. An aqueous media was also The use of aqueous media for carrying out catalytic reactions has many attractions and in 2017, Matsinha et al reported the synthesis of two water-soluble palladium complexes 20a and 20b containing sulfonated-thiosemicarbazone ligands (Figure 3) [113]. In both complexes, the ligand is tridentate, and the vacant position is occupied by a tertiary phosphine (PPh 3 in 20a and 1,3,5-triaza-7-phosphaadamantane in 20b).…”

[2 × 2] Molecular Grids of Ni(II) and Zn(II) with Redox-Active 1,4-Pyrazine-Bis(thiosemicarbazone) Ligands

“…Bi-or oligonuclear transition metal complexes of thiosemicarbazone ligands have been obtained frequently through S-bridging of the thiosemicarbazone ligands [3,4,8,[12][13][14][15][16][17][18][19][20]. Systematic formation of bi-or oligonuclear complexes through ligand design has successfully used functionalised mono-thiosemicarbazone ligands, such as the 2-(di(pyridyl-2-yl)thiosemicarbazone [13,21] or bis(thiosemicarbazone) ligands [4,5,9,[20][21][22][23][24][25][26][27]. For example, pyridine-2,6-bis(thiosemicarb azones) (Scheme 1C) have been synthesised to provide a potential S^N^N^N^S coordination for the metal [4,10,22,28,29] and were found to form binuclear complexes through S-bridging [22,29], but they largely fail to bridge two metal centres due to their preference for multi-dentate binding [4,10,22,28].…”