Catalysis for life sciences

Dr. Helfried Neumann

Research activities:

Deuteration

Deuterium-labeled compounds find vast applications across diverse fields such as drug discovery and bioanalytics as well as being routinely employed as starting materials in mechanistic studies for the determination of kinetic isotope effects (KIE) or the identification of reactive sites. We investigate the synthesis of these important compounds based on hydrogen isotope exchange (HIE) and other labeling techniques. In this context, the hydrogen-borrowing concept has been applied to the deuteration of aliphatic amines whereas transition metal-catalyzed C-H activation could afford selective labeling of aromatic compounds. We are currently interested in the development of homogeneous catalysts for deuteration reactions with abundant and practical isotope sources.

Perfluoralkylation of Arene Compounds

The synthesis of fluorine containing aromatic compounds is a special challenge when a hydrogen atom is substituted by a perfluoralkyl group. We developed a heterogeneous catalyst, which is doing this job in the presence of bases and perfluoro alkylhalides. Especially important is the modification of active agent by substitution of a CF3- or CF2 group. As CF2-source we developed a scalable difluoromethylation agent, which is allowed to react with different nucleophiles giving modified fluorine containing molecules.

Ligand- and Complex Syntheses

Phosphine ligands play still an outstanding role in the homogeneous catalysis. In cooperation with EVONIK we are working out a synthesis of highly efficient chelating ligands, which are finally used in alkoxycarbonylations of olefines. To get a better mechanistically understanding we are synthesizing corresponding palladium complexes and follow elementary steps by NMR spectroscopy.

Carbonylation Reactions

The palladium-catalyzed carbonylation of activated ArX compounds is a long standing area of research and it is fascinating how multi faced this chemistry can be. The famous CO-insertion step in a PdArX bond is here only one intermediate step of a cascade of many reaction steps, which finally ends up in the formation of highly substituted heterocycles. The carbonylation of the cheaper but mostly less reactive aryl chlorides is still a challenge, which needs certain reaction conditions and catalysts.