Synthesis of multi(metallo)porphyrin dendrimers through nucleophilic aromatic substitution on meso-pyrimidinyl substituted porphyrins.

A convergent synthetic strategy toward novel all-porphyrin dendrimers, which can be regarded as synthetic model systems of the natural photosynthetic light-harvesting antennae, was successfully explored. The dendron propagation, based on nucleophilic aromatic substitution reactions on a meso-dichloropyrimidinyl substituted porphyrin AB2 monomer, was carried out up to the second-generation dendron, and the used approach was proven to be compatible with the stepwise introduction of different metals in the successive generations. Three different metals (Pt, Zn, and Ni) could be introduced in the second-generation heptaporphyrin dendron. By applying analogous meso-dichloropyrimidinyl substituted porphyrin cores, novel multiporphyrin dendrimers were obtained.