Modulating the catalytic activity by the mechanical bond: organocatalysis with polyamide [2]rotaxanes bearing a secondary amino function at the thread†
Abstract
The modulation of the catalytic activity of degenerate succinamide-based [2]rotaxanes by changes at their macrocyclic component is disclosed herein. These systems, bearing an acyclic secondary amine function at the thread as the active site and incorporating different polyamide macrocycles, were evaluated as organocatalysts in iminium- and enamine-type processes. The results of kinetic studies clearly show a drastic variation of their catalytic efficiency, which apparently correlated with the electronics and dynamics of the entwined macrocycle.