Catalysis

Anion-π catalysis, that is the stabilization of anionic transitions states on π-acidic aromatic surfaces, was introduced explicitly by this group in 2013. Since then, we demonstrated asymmetric anion-π catalysis for enolate, enamine, iminium and transamination chemistry, and prepared the first anion-π enzyme. Because of their delocalized nature, anion-π interactions are particularly suited to stabilize long-distance charge displacements in cascade processes.

We currently focus on advanced anion-π catalysts and their integration into more complex systems. Naphthalenediimides (NDIs) will remain as privileged platforms for anion-π catalysis, but possible alternatives will not be ignored. Considering many attractive anionic transition states we all know of, we are keen on achieving anion-π catalysis for reactions of outstanding importance.

Catalysis with other "exotic" interactions is also very appealing. Early 2017, we reported the first example for non-covalent catalysis with chalcogen bonds. Dithienothiophenes (DTTs) have been introduced as privileged structure for powerful chalcogen bonds that is reminiscent of classics such as bipyridines for cation binding or bipyrroles for anion binding with hydrogen bonds. For catalysis, chalcogen bonds can be considered as complementary to the more delocalized anion-π interactions, with focused sigma holes to operate at high precision in hydrophobic media.

The introduction of anion-π interactions and chalcogen bonds offers the perspective to establish totally new grand principles in catalysis, a very special and very exciting situation that promises highest impact in the broadest sense and thus deserves much attention.

Methods: This project is ideal for those who are interested in synthetic methodology combined with substantial multistep synthesis. Integration into complex systems can, if desired, provide additional experience with proteins, lipid bilayer membranes and organic chemistry on conductive solid surfaces.

Collaborations: Computational simulation (with Jiri Mareda), protein engineering for artificial enzymes (with Tom Ward).

Some recent references: Angew. Chem. Int. Ed. 2017; ACS Cent. Sci. 2016; J. Am. Chem. Soc. 2016.