Rare-Earth Metal-Promoted C-H Bond Activation

The production of valuable chemicals via selective functionalization of saturated and unsaturated hydrocarbons is a major challenge in the field of contemporary organometallic chemistry. A particularly attractive substrate is methane which has previously been successfully C-H bond activated by electrophilic late transition organometallics under harsh conditions. Highly electron-deficient donor solvent-free metallocene complexes of the rare-earth elements were also shown to activate methane via non-oxida tive mechanisms (e.g., sigma bond methathesis). Such activation scenarios were successfully exploited for catalytic (stereoselective) hydrosilylation reactions. The goal of this project is to sound out the C-H bond activation capability of various rare- earth metal tetramethylaluminate complexes which have been recently synthesized in our group. Main emphasis will be put on studying monocyclopentadienyl and postmetallocene derivatives with respect to in situ generation of reactive Ln-alkyl bonds and lab eling experiments. Consideration is given to aliphatic, olefinic, and aromatic substrates including donor-functionalized molecules such as pyridine.