The Melvin Calvin Lecture in Organic Chemistry: Bioinspired Asymmetric Catalysis with Peptides and Other Small Molecules

Seminar | February 7 | 11 a.m.-12 p.m. |  Pitzer Auditorium, 120 Latimer Hall

 Prof. Helma Wennemers, Laboratory of Organic Chemistry, ETH Zurich

 College of Chemistry

In nature, proteins fulfill manifold different functions and are crucial as, for example, enzymes or templates for the controlled formation of structural components such as bones. The Wennemers group is intrigued by the question whether also peptides with significantly lower molecular weights compared to proteins can fulfill functions for which nature evolved large macromolecules. Specifically we ask whether peptides can serve as effective asymmetric catalysts, templates for the controlled formation of metal nanoparticles, synthetic collagen based materials, or tumor targeting vectors.

The lecture will focus on the development of peptides as asymmetric catalysts. Tripeptides of the general type H-Pro-Pro-Xaa (Xaa = amino acid with a carboxylic acid) will be presented that are effective catalysts for aldol and conjugate addition reactions. The peptides allow for catalysis via an enamine mechanism with catalyst loadings of as little as 0.1–1 mol% and provide synthetically versatile products in high stereoselectivities. Several synthetically valuable compounds such as -amino acids are easily accessible using this methodology.

The scope of these peptide-catalyzed reactions will be presented and recent insight into the mechanism as well as the importance of conformational properties for effective catalysis will be discussed.

 Light refreshments served at The Coffee Lab at 10:50am., 510-643-0572