Entwicklung Neuer Übergangsmetall-Katalysierter Transformationen

The development of new flexible methods to obtain useful added-value products from simple and cheap materials is of high interest. The homogeneous transition metal catalysis delivers various processes and a brought range of new mechanisms to this field. We investigate transition metal catalyzed processes using complexes of redox-coupled ligands to obtain relevant especially nitrogen containing compounds. New ligand systems that are suitable for electronic coupling are developed and their corresponding transition metal complexes are generated. Especially ruthenium cyclopentadienone derivatives provide unique features towards catalytic transformations of bifunctional substrates like propargyl alcohols due to redox-coupling of the dienone ligand and its basic coordination site. Following this concept the rage of selective catalytic transformations of propargyl alcohols with ruthenium catalysts could be widely extended. The formation of neutral vinyliden- and allenyliden-species as central intermediates in catalytic cycles is of major interest since these species represent a framework of selectively addressable carbon atoms suitable for regioselective additions of functionalized nucleophiles followed by cyclization-processes. Such catalytic transformations allowing high flexibility regarding suitable educts and stereochemical aspects are applied to the synthesis of simple heterocycles as well as natural products and their analogues.