Novel Ruthenium Complexes with Sterically Demanding Cyclopentadienyl Ligands: Syntheses, Reactivity and Catalytic Applications
Investigations of ruthenium halfsandwich complexes have mostly focused on Cp and Cp* based derivatives due to the availability of easily accessible starting materials. However, it is interesting to have complexes with substituted cyclopentadienyl ligands in order to study the influence of the π-ligand on the chemical behavior of the complexes, as well as to fine-tune their properties. During the course of this thesis, ruthenium complexes with novel, highly substituted cyclopentadienyl ligands ('Cp^') were prepared in one-pot syntheses from commercially available starting materials and under mild reaction conditions. The complexes are versatile starting materials leading to a variety of Cp^Ru complexes through facile ligand exchange reactions. The chemistry of Cp^Ru-complexes has been investigated and the general reactivity pattern was found to be similar to that of CpRu and Cp*Ru complexes. However, in several instances it was observed that the steric and electronic properties of the Cp^ ligand have a strong impact on the properties and chemical behavior of the complexes. As a consequence of the sterically demanding Cp^ ligand, coordinatively unsaturated complexes, that are otherwise inaccessible, have been stabilized. In addition, the presence of the Cp^ ligand resulted in unusual CO insertion reactions and in an unprecedented rearrangement of cyclooctadiene. Some Cp^Ru-complexes turned out to be very efficient catalysts for organic transformations such as the [2+2+2] alkyne cyclotrimerization and atom transfer radical cyclizations. Activation of molecular oxygen was also accomplished with Cp^Ru complexes. In vitro studies with Cp^Ru complexes have shown that they exhibit high cytotoxicity towards human cancer cell lines.
Programme doctoral Chimie et Génie chimique
Faculté des sciences de base
Institut des sciences et ingénierie chimiques
Laboratoire de chimie supramoléculaire
Record created on 2010-07-15, modified on 2016-08-08