Responsive organocatalysis in soft materials

Abstract

Cells react to the environment by changing the activity of enzymes. Catalysts, such as enzymes, speed up reaction rates by lowering the activation energy of the reaction. Changing reaction rates by altering enzyme activity is used to temporarily increase the production of, for instance, a hormone or to change the mechanical properties of a cell. Control over enzyme activity is achieved in two different ways: by covalent modifications (e.g. phosphorylation) and by non-covalent interactions (allosteric enzymes). In this thesis we describe how we designed signal-responsive catalysts and used them to introduce signal response in artificial materials. Inspired by nature we developed a covalent and a noncovalent method to design catalysts that can react to signals from their environment. To design covalently protected catalysts we used self-immolative chemistry. A self-immolative molecule contains a signal-labile functional group. When this group reacts with the signal, the molecule fragments and releases a molecule of interest, in our case a catalyst.