The convergent synthesis of second generation AB-type miktoarm block-dendrimers using efficient and high yielding click chemistry catalyzed by copper (Cu) wire is demonstrated. The advantages of carrying out click reactions with Cu include higher purity and greater click efficient reactions, performing click reactions in the absence of N-based ligands, removal of excess copper species from the reaction mixture, and the reuse of same copper wire in all subsequent click reactions. The convergent strategy provides a tool to prepare dendrimers with chemical diversity in each generation that cannot be achieved using a divergent strategy. Comproportionation also provides a constant source of Cu(I) species to give high yields from click reactions using Cu (wire). This is additionally aided through the strong stabilization of the Cu(I) species with the preformed triazol rings in starting polymer structures.
Urbani, C. N., Bell, C. A., Whittaker, M. R., & Monteiro, M. J. (2008). Convergent synthesis of second generation AB-type miktoarm dendrimers using "click" chemistry catalyzed by copper wire. Macromolecules, 41(4), 1057 - 1060. https://doi.org/10.1021/ma702707e