Convergent Synthesis and Characterization of Dumbbell Type Dendritic Materials by Click Chemistry

General, fast, and efficient stitching methods for the synthesis of dendrimers with linear PEG units at a core, as dendritic-linear-dendritic materials, were developed. The synthetic strategy involved the click reaction between an alkyne and an azide. The linear core building blocks, three dialkyne-PEG units, were chosen to serve as the alkyne functionalities for dendrimer growth via click reactions with the azide-dendrons. These three building blocks were employed together with the azide-functionalized Frechet-type dendrons in a convergent strategy to synthesize the Frechet-type dendrimers with different linear core units. Their structure of dendrimers was confirmed by ¹H and ¹³C NMR spectroscopy, IR spectroscopy, mass spectrometry, and GPC analysis