Entwicklung chiraler Cp*-artiger Liganden und Anwendung in asymmetrischen C–H-Aktivierungsreaktionen
Zusammenfassung der Projektergebnisse
The project deals with the design of novel chiral ligands and their application in asymmetric transition metal catalysis. In contrast to the original proposal, we have changed the ligand scaffold to bisimine-type ligands. We have established an asymmetric synthesis of cyclooctadienes, which are of great interest as scaffolds in natural products or as ligands in transition metal catalysis. Until now, methods to efficiently access this motif in an enantioselective manner were lacking in literature. The transformation is catalyzed by iron, one of the most earth-abundant, cheap and non-toxic metals available. For ligand optimization, a library of more than 40 bisimine-type ligands and their corresponding iron complexes has been established, enabling easy screening for future application in different transformations. The reaction proceeds in excellent yields and selectivities for a variety of different substrates. Investigations of the scope are currently still ongoing in the group of Professor Cramer, as well as potential derivatizations of the chiral cyclooctadiene products and their application as ligands in transition metal catalysis.
