Regiospecific naphthyl nitration of 5,10,15,20-tetranaphthylporphyrin

摘要

The nitration reaction of 5,10,15,20-tetranaphthylporphyrin (TNP) was investigated in detail and the mono-, di-, and tri-nitro-TNPs were synthesized in high yield using 65% HNO_3. The ~1H-NMR study shows that the preferred site of nitration of the naphthyl substituted porphyrin is the carbon atom of the meso-substituents para to its bond to the porphyrin ring. The reaction leads to exquisite regioselectivity in favor of the mono, di, and tri-nitro-TNP. Quantum-chemical ab initio calculations at different levels of theory were performed in order to explain the experimentally observed reactivity.