Novel Route to Functionalized Tetraaryltetra[2,3]naphthaloporphyrins via Oxidative Aromatization

A novel general route to substituted meso-tetraaryltetra[2,3]naphthaloporphyrins (Ar4TNP) and meso-tetraaryloctamethoxytetra[2,3]naphthaloporphyrins (Ar4(MeO)8TNP) via oxidative aromatization of nonaromatically fused porphyrin precursors is described. Ar4(MeO)8TNPs exhibit more red-shifted absorption bands than Ar4TNPs and differ dramatically in solubility. The first X-ray crystallographic structure of tetranaphthaloporphyrin, i.e., PdAr4TNP (Ar = 4-MeO2CC6H4), revealed that the degree of nonplanar distortion of this macrocycle is only slightly higher than that of the homologous tetrabenzoporphyrins (Ar4TBP).