Towards the optimization of polymer-supported catalysts: Relationship between local reaction medium and catalyst efficiency

In order to optimize the design of polymer-bound dialkylaminopyridine catalysts, several such heterogeneous catalysts have been evaluated in the acylation of a hindered tertiary alcohol. In particular, the microenvironment and local polarity near the catalytic sites and its influence on catalyst performance has been studied. Comparisons with literature data provide an explanation for some of the differences in reactivities observed by others and confirm that it is important to design the catalysts such that their reactive sites are surrounded by non-polar moieties. Novel approaches such as the grafting of reactive groups onto polyethylene or polytetrafluoroethylene have been tested.