Competition versus Cooperation in Catalytic Hydrogelators for anti-Selective Mannich Reaction

5 years ago

Competition versus Cooperation in Catalytic Hydrogelators for anti-Selective Mannich Reaction

Nishant Singh, Beatriu Escuder

Chemical systems find similarities in different sociological and biological processes, in which the entities compete or cooperate for a favorable outcome. The structural and functional adaptations leading to emergent properties, especially in catalysis, are based on factors such as abundance of substrates, stability of the transition state, and structural/functional attributes of catalysts. Proline and acid groups appended to catalytic fibers of two self-sorting hydrogelators compete for the Mannich reaction between aniline, benzaldehyde, and cyclohexanone to give low overall selectivity (anti/syn 77:23). In a sol–gel system of the same molecules, on the other hand, the soluble acid appended molecules tend to cooperate with the fibers of proline-appended catalyst to give improved selectivity (anti/syn 95:5). The available options for the catalytic molecules are to carry out the reaction independently or in cooperation. However, these options are chosen based on the efficiency, selectivity, and mobility of catalysts as a result of their abilities to self-assemble. Team players: A bottom-up approach can be used to construct functional architectures through noncovalent interactions between self-assembling molecules. Such self-sorted, co-assembled, and sol–gel systems constructed from the same building blocks can have different emergent properties that depend on the relative positioning of the molecules and the final self-assembled structures.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201701724