Facile Synthesis of a Tadpole-Shaped Dendrimer Based on N-Alkylated Oligo(p-benzamide)

A novel, rapid, inexpensive, and highly accelerated approach for the synthesis of a tadpole-shaped dendrimer possessing monodisperse N-alkylated oligo(p-benzamide) as a rod block with a precise length and an amine-terminated dendritic block based on 3,5-diaminobenzoic acid has been developed. The N-alkylated oligo(p-benzamide)s were prepared by an rapid stepwise method using thionyl chloride as an activating agent and trifluoroacetamide as the protecting group for the end amine, in which the number of amide units dramatically propagated only through every deprotection and condensation. From this rod block, each generation of dendron rod molecules was formed divergently using 3,5-bis(trifluoroacetamido)benzoyl chloride as an AB₂ building block.