Interfacial catalysis of aldol reactions by prolinamide surfactants in reverse micelles

L-Proline and their derivatives are among the most important class of organic catalysts. Three prolinamide surfactants were designed and synthesized. Although the surfactants carried identical catalytic groups, their headgroups contained different functionalities that affected their ability to self-assemble under reverse micelle conditions and hydrogen-bond with the reactants. The surfactant with a zwitterionic headgroup capable of strong aggregation was found to have the highest activity. The self-association of the surfactants played critical roles in the enhanced activity. The location of the catalytic groups at the surfactant/polar solvent interface also endowed unusual selectivity in the catalyzed aldol reactions.