Fri, Nov. 16, 2018, 4:30pm
Edward C. Taylor Auditorium, Frick B02
Host: Robert Knowles
Learning from Nature: Designing Self-Amplifying Enantioselective Catalysts
Self-amplifying enantioselective reactions are important in the context of the Origin of Life to explain the formation of homochirality in Nature. The understanding of such complex mechanisms leading to amplification of chirality is the key to a directed design of such reactions and catalysts. The most prominent example of an autocatalytic process is the Soai reaction. In this presentation mechanistic investigations and a novel mechanism of the Soai reaction will be presented with a focus to transfer the knowledge to other reactions and processes.
In particular stereolabile interconverting catalysts open up the possibility of directing enantioselectivity in asymmetric synthesis by formation of diastereomeric complexes with chiral auxiliaries.[2,3] The successful realization of such a system by decoration of the ligand backbone with chiral recognition sites attached to a structurally flexible phoshoramidite type catalyst, that can sense the chirality and induce enantioselectivity, is presented. Structural flexibility and sensing of the chirality of product molecules result in a rapid increase of enantioselectivity of the dynamic catalysts (Δee of up to 76%) and a shift out of equilibrium.
 K. Soai, T. Shibata, H. Morioka, K. Choji, Nature 1995, 378, 767-768.  F. Maier, O. Trapp, Angew. Chem. Int. Ed. 2012, 51, 2985-2988.  G. Storch, O. Trapp, Angew. Chem. Int. Ed. 2015, 54, 3580-3586.  G. Storch, O. Trapp, Nature Chemistry 2017, 9, 179-187.