Convergent Synthesis of Second Generation AB-Type Miktoarm Dendrimers Using “Click” Chemistry Catalyzed by Copper Wire

Dendrimers synthesized from small molecules form macromolecules of well-defined size and architecture.1 The high density of functional groups on the periphery of the dendrimers makes them useful as carriers for multiple copies of biologically active compounds for drug/vaccine delivery or probe molecules for detection applications.2 However, the typical synthetic procedure for obtaining dendrimers from small molecules limits their size to about 5−15 nm as each new generation is increasingly difficult to add and contributes only to a relatively small increase in dimensions. In addition, traditional dendrimers are difficult to purify and as a consequence costly. Thus, the focus in synthetic dendrimers has shifted from using small molecule to polymeric building blocks made by living radical polymerization.3 However, there is still a need in precise synthetic tools that would allow one to combine polymeric blocks with diverse functionality into one structure to create advanced products for biomedical and coatings applications.