Efficient Synthesis of Dendrimers via A Chemoselective Approach

Significance

The dendrimer derivatives of the Fréchet-type and 2,2-bis(methylol)propionic acid (bis-MPA) dendrimers were synthesized via an accelerated growth approach, which is based on the combination of click chemistry with traditional esterification/etherification reactions. The required monomer units for one-step generation growth are AB₂-monomer (2) and CD₂-monomer (4). The synthetic strategy allows the divergent preparation of a fourth-generation dendrimer (2^nd generation dendrimer 5 is shown) in only four steps and in multi-gram quantities with an overall yield of 70% from the starting triphenol 1. The obtained dendritic block copolymer contains alternating layers of benzyl ether, triazole and benzyl ether groups. The orthogonality and efficiency of this strategy were demonstrated by monitoring each reaction with NMR and MALDI-TOF techniques.