Catalysis of Early Transition Metals

Dr. Fabian Reiß

The group investigates fundamental aspects of early transition metal catalysed processes on the basis of synthetic organometallic chemistry and coordination chemistry. We focus on coordination and activation of small unsaturated molecules (e.g. olefins, alkynes, isocyanides, nitriles, and CO2) at group 4 metal complexes that allow for the stoichiometric and catalytic generation and stabilisation of partly unusual organometallic and organic structures.1

We are investigating the chemistry of unusual group 4 metallacycles in order to explore the scope of coordination chemistry of this class of compounds. In general, incorporation of unsaturated units into cyclic structures increases ring strain, which typically decreases the stability and the accessibility of such compounds. However, formal substitution of e.g. methylene units for suitable metal fragments allows for the synthesis of a series of exotic complexes. After evaluating different approaches and optimization of the synthesis of a suitable organolithium synthon, we have succeeded in the isolation of a titanacyclobuta-2,3-diene, which formally represents an organometallic analogue of cyclobuta-1,2-diene.2 Variation of the metallocene precursor and use of Cp2ZrCl2 results in the formation of an unusual eight-membered metallacycle. Structural and electronic properties of these and related complexes are investigated using a combined experimental and theoretical approach based on up-to-date analytical and computational tools.