Ligand properties augmentation through modification with diamondoids

Abstract

Diamondoids, a type of polycyclic hydrocarbons resembling small diamond cages, are long established in research and industry. Their chemical stability, conformational rigidity, spatial bulkiness, and excellent electron-donor abilities make them versatile lattices for numerous applications through their further functionalization or the augmentation of existing molecules. In this dissertation we explore further the impact of diamondoid modification by investigating a novel series of adamantane-containing NHCs based on the original Arduengo carbene. We also demonstrate the first application of diamantane functionalization in generating a potent ligand for the platinum family of anticancer drugs. In the first publication, in collaboration with the research group of Prof. Dr. Grzegorz Mlostoń from University of Łódź we reported on a series of adamantylated oxyimidazolium salts that could be used to generate N-alkoxyheterocyclic carbenes analogous to the first stable carbene isolated by Arduengo. We isolated the carbene that showed the largest upfield 13C NMR shift compared to common NHCs. We further analyzed the properties of investigated carbenes through their gold(I) and selenium complexes. The second publication builds upon discovering a straightforward way to previously inaccessible 1,2-vicinal diamantane derivatives, particularly chiral 1,2-diaminodiamantane. It is used to generate bulky and lipophilic Pt(II) dichloride and oxalate complexes. R,R-enantiomeric dichloride complex, tested on human ovarian cancer cell lines A2780 and cisplatin-resistant A2780cis, showed superior activity to the potent anticancer drug cisplatin.