Functionalizing the interior of dendrimers: Synthetic challenges and applications

Abstract

Chemists' fascination with dendrimers mainly originates from their unique architecture and its exploitation for the design of well‐defined functional macromolecules. Depending on the nature of the synthesis, functionalization is traditionally introduced at the core, the periphery, or both. However, the specific incorporation of functional groups at the interior layers, i.e., generations, represents a considerable synthetic hurdle that must be overcome for the full potential of dendrimers to be realized. This review covers recent advances in this emerging frontier of dendrimer science with a particular focus on covalent modifications. Monomer design, syntheses, and properties of various dendritic backbone types are discussed. Internal functionalization dramatically increases the degree of complexity that can be implemented into a dendrimer macromolecule and, therefore, promises to lead to smart materials for future applications in bio‐ and nanotechnologies. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1047–1058, 2003

Z. Guan, Control of polymer topology through late‐transition‐metal catalysis, J Polym Sci Part A: Polym Chem (2003), 41(22), 3680–3692

“…It is reasonable to expect that many physical properties of these dendritic polymers made by the chain-walking catalyst should be similar to those of a perfect dendrimer made of the same building blocks. Although perfect dendrimers have beautiful structural precision and uniformity and provide the best site isolation to the dendrimer cores, 3,[5][6][7][8] the multistep syntheses involved in their preparations sometimes limit their general applications. Our approach offers a simple one-pot process for making tunable polymers with topologies ranging from linear to hyperbranched to dendritic that starts with simple olefinic monomers.…”

“…37 The need to synthesize polymers with unusual properties has driven the effort to design polymers with new architectures. 38 One approach is to introduce branches into the polymer backbone to produce architectures such as dendritic structures [5][6][7][8] and their practical analogues, hyperbranched structures. 9 -15 Most hyperbranched polymers are made from the condensation polymerization of AB 2 -type monomers.…”

“…2,3 A significant amount of effort has been devoted to developing efficient methods for accurately controlling polymer topology and architecture with the aim of preparing polymeric materials with new properties. 4 Many concepts and synthetic approaches have been developed to prepare macromolecules with various architectures and topologies, including dendrimers [5][6][7][8] and hyperbranched polymers, 9 -15 supramolecular polymers, 16 -21 cylindrical and spherical polymers, [22][23][24] polymers having folded structures, [25][26][27] molecular wires, 28 -30 metal-core polymers, 31,32 and polymeric nanostructures. [33][34][35] Vinyl polymers are an important category of synthetic materials, with millions of tons produced every year for broad applications such as fibers, plastics, and elastomers.…”

Dendrimers based on [1,3,5]‐triazines

“…More general accounts of dendrimers, their nomenclature, and synthetic routes useful for their preparation can be found elsewhere. [1][2][3][4][5] WHY TRIAZINES?…”

Dendrimers Clicked Together Divergently

“…15,[36][37][38][39][40][41][42] Coincident with these developments is the increasing need for facile, costeffective methods that provide covalent connections between dendrimer generations, either convergently 43 or divergently, 44,45 and for variability in the composition and properties of the dendritic scaffold. Although many families of dendrimers have been produced, there remain opportunities for further developments, especially given the iterative growth scheme, which require efficient and versatile chemistries for the preparation of well-defined dendrimers.…”