Prof. Bernhard Breit: "Molecular Catalysts Through Self-Assembly for Organic and Soft Matter Synthesis"

An ideal chemical transformation should be efficient, selective and intrinsically waste-free. Reactions meeting these requirements are synthetic reactions initiated and steered by a suitable catalyst. A catalyst can be either heterogeneous (the surface of a solid has catalytic properties – compare the catalytic converter in the exhaust pipe of your car) or homogeneous (small organic or metal organic molecules which dissolve in the reaction phase). These molecular catalysts require tailor-made ligands, which bind to the catalytically active metal center, craft the microenvironment of the catalyst, and thus, allow for selectivity control. Problematic however, is the right choice of this ligand, which is still a process driven by intuition, hard labour and serendipity. Thus, combinatorial approaches to accelerate the ligand/catalyst discovery process have emerged. However, this approach suffers from the limited access towards structurally diverse and meaningful ligand libraries, which is caused by the difficulty of ligand synthesis. As a solution to this problem, we devised a fundamentally new way towards molecular defined catalysts based on the principle of self-assembly. Thus, inspired by DNA base pairing, we developed A–T base pair analogous heterocyclic platforms, which allow for catalyst self-assembly through complementary hydrogen-bonding. From such ligand libraries, excellent catalysts for a number of important synthetic reactions have emerged.[1-4]