Catalysis Inside Dendrimers

Abstract

Modern methods that involve intradendritic catalysis are introduced in this feature article. Supramolecular principles, therefore, derive from the concept of the unimolecular dendritic micelle introduced by Newkome. When the micellar effect is combined with intradendritic ligand acceleration, copper(I) catalysts or palladium nanoparticles (PdNPs) are required at the ppm level for efficient reactions. Applications range from organic catalysis to catalysis by metal complexes of intradendritic ligands and dendrimer-stabilized nanoparticles (NPs) that are located at the dendrimer core or between the dendrimer tethers. Bimetallic nanoparticle-cored dendrimers including superparamagnetic iron oxide nanoparticles (SPIONs) are especially promising due to very facile magnetic separation.

Catalytically Active Palladium Nanoparticle‐Cored Ferrocenyl‐Terminated Dendrimers

“…The presence of redox-active metallocenic groups [60,61] at the dendrimer periphery should in the future also allow modulation of the intradendritic catalytic activity [62] by variation of the charge and bulk of the organometallic termini.…”

Dendrimer crown-ether tethered multi-wall carbon nanotubes support methyltrioxorhenium in the selective oxidation of olefins to epoxides

“…9 These supramolecular aggregates are characterized by recognition sites on both the dendrimer core and the end-termination of the system. 10,11 The divergent methodology for the preparation of PAMAM dendrimers encompasses the graing of 1,3-diamino propane intermediates with methyl acrylate and ethylenediamine, followed by linkage of the crown ether moiety. The chemical complexity of PAMAM dendrimers (number of dendrimer sidechains and type of ramication) depends on the successive methyl acrylate/ethylenediamine treatments, and controls the distribution of the recognition sites, the leaching of the active species, [12][13][14] and the dispersibility of MWCNTs in organic solvents.…”

Synthesis and Catalytic Applications of Multi‐Walled Carbon Nanotube–Polyamidoamine Dendrimer Hybrids

“…On the contrary, dendrimeric architectures like polyamidoamines (PAMAM) dendrimers display high solubility, reactive peripheral amino groups, and, unlike most polymers, are accurately defined . These structures offer, for instance, precise spots for catalytic sites, that is, in the dendrimer core or at its terminations . Those locations are able to host either metallic nanoparticles (NPs) or organometallic complexes for homogeneous‐like catalytic applications .…”

“…These structures offer, for instance, precise spots for catalytic sites, that is, in the dendrimer core or at its terminations . Those locations are able to host either metallic nanoparticles (NPs) or organometallic complexes for homogeneous‐like catalytic applications . Dendrimers can also fulfill the role of encapsulating vectors in the field of nanomedicine and are intensively studied in drug delivery systems …”