The dendrimer effect in homogeneous catalysis

The immobilization of catalytic groups onto a dendritic support either at the core or at the periphery gives rise to unique properties that affect rates of reaction, substrate activation or selectivity, etc. When advantageous, these properties can be classified as a positive dendrimer effect. Positive dendrimer effects can arise from site isolation, transition state stabilization and/or dielectric effects in the case of core-modified dendrimers, while peripherally modified dendrimers usually benefit from steric crowding or cooperativity for catalytic residues confined to the surface of the polymer. In this review, the appearance of positive dendrimer effects from the literature will be highlighted as well as prospects for future work in the field. 1. Introduction 2. Commonly Used Dendrimer Platforms for Macromolecular Catalysts 3. Core-Functionalized Dendrimers in Catalysis 4. Peripherally Modified Dendrimers in Catalysis 5. Conclusion and Outlook