Anti-cancer palladium complexes: a focus on PdX2L2, palladacycles and related complexes

Biologically active [Pd2L4](4+) quadruply-stranded helicates: stability and cytotoxicity

There is emerging interest in the anti-proliferative effects of metallosupramolecular systems due to the different size and shape of these metallo-architectures compared to traditional small molecule drugs. Palladium(II)-containing systems are the most abundant class of metallosupramolecular complexes, yet their biological activity has hardly been examined. Here a small series of [Pd2(L)4](BF4)4 quadruply-stranded, dipalladium(II) architectures were screened for their cytotoxic effects against three cancer cell lines and one non-malignant line. The helicates exhibited a range of cytotoxic properties, with the most cytotoxic complex [Pd2(hextrz)4](BF4)4 possessing low micromolar IC50 values against all of the cell lines tested, while the other helicates displayed moderate or no cytotoxicity. Against the MDA-MB-231 cell line, which is resistant to platinum-based drugs, [Pd2(hextrz)4](BF4)4 was 7-fold more active than cisplatin. Preliminary mechanistic studies indicate that the [Pd2(hextrz)4](BF4)4 helicate does not induce cell death in the same way as clinically used metal complexes such as cisplatin. Rather than interacting with DNA, the helicate appears to disrupt the cell membrane. These studies represent the first biological characterisation of quadruply-stranded helicate architectures, and provide insight into the design requirements for the development of biologically active and stable palladium(II)-containing metallosupramolecular architectures.

Synthesis and anticancer activities of a novel class of mono- and di-metallic Pt(ii)(salicylaldiminato)(DMSO or Picolino)Cl complexes

Mono- and di-metallic Pt(ii)(salicylaldiminato)(DMSO or Picolino)Cl complexes as potential cytotoxic agents against tested human breast (MCF-7), liver (HepG2), lung (A549), colon (HCT116) and cervical (Hela) cancer cell lines.

Palladium(0)-mediated C–H bond activation of N-(naphthyl)salicylaldimine and related ligands: utilization of the resulting organopalladium complexes in catalytic C–C and C–N coupling reactions

Aldimine ligands undergo palladium(0) mediated C–H bond activation to afford cyclopalladated complexes, which efficiently catalyze C–C and C–N coupling.

Selective palladium-catalysed arylation of 2,6-dibromopyridine using N-heterocyclic carbene ligands

A selective palladium-catalysed arylation of 2,6-dibromopyridine has been developed by employing N-heterocyclic carbene ligands. Selective mono-arylation was performed in water/acetonitrile solvent at ambient temperature and low catalyst loading.

Sugar-boronate ester scaffold tethered pyridyl-imine palladium(ii) complexes: synthesis and their in vitro anticancer evaluation

The anticancer activity of sugar-boronate ester containing palladium(ii) complexes is reported.

σ-Alkenyl endo-palladacycle formation via regiospecific functionalisation of an unreactive NHC-tethered C(sp2)–H bond

A highly unusual cyclometallation reaction in which an aliphatic vinylic C(sp²)–H bond is activated to form a σ-vinyl palladacyclic–NHC complex is reported.

Potential apoptosis inducing agents based on a new benzimidazole schiff base ligand and its dicopper(ii) complex

Synthesis, characterization and DNA/protein binding studies of new benzimidazole based dicopper(ii) complex inducing apoptosis in MCF-7 cells have been presented.