Cancer is a health issue worldwide. Gold-based drugs like Auranofin achieve high selectivity, and therefore, lower strain on healthy cells by targeting multiple enzymes and mechanisms overexpressed in cancerous cells. The anti-cancer properties and high activity of Auranofin are attributed to a simple phosphorous ligand featuring ethyl groups: -PEt3.[1] This crucial structural element can be applied to existing digold drugs, which utilise the more common phosphine-aryl ligands. An example is [ClAu(µ-2-C6F4-PPh2)(κ2-2-C6F4-PPh2)AuCl] 1, which contains dual active gold centres with oxidation state +I and +III, resulting in unique and better anti-cancer activity. This avoids developed resistances towards metal drugs and opens multiple mode of actions to inhibit cancer growth.[2] The complex above can be prepared by oxidising [Au2(µ-2-C6F4-PPh2)2] 2 with PhICl2 to [Au2Cl2(µ-2-C6F4-PPh2)2] 3. Heating of a solution of 3 in toluene results after disproportionation in 1.[3]
We theorise that the introduction of the Phosphorous-alkyl motif into digold complexes ([ClAu(µ-2-C6F4-PEt2)(κ2-2- C6F4-PEt2)AuCl] 4) will enhance their biological activity. Additionally, the synthesised complexes are wholly new and were fully characterised by single-crystal XRD, NMR spectroscopy and others.