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

A novel general route to substituted <i>meso</i>-tetraaryltetra[2,3]naphthaloporphyrins (Ar<sub>4</sub>TNP) and <i>meso</i>-tetraaryloctamethoxytetra[2,3]naphthaloporphyrins (Ar<sub>4</sub>(MeO)<sub>8</sub>TNP) via oxidative aromatization of nonaromatically fused porphyrin precursors is described. Ar<sub>4</sub>(MeO)<sub>8</sub>TNPs exhibit more red-shifted absorption bands than Ar<sub>4</sub>TNPs and differ dramatically in solubility. The first X-ray crystallographic structure of tetranaphthaloporphyrin, i.e., PdAr<sub>4</sub>TNP (Ar = 4-MeO<sub>2</sub>CC<sub>6</sub>H<sub>4</sub>), revealed that the degree of nonplanar distortion of this macrocycle is only slightly higher than that of the homologous tetrabenzoporphyrins (Ar<sub>4</sub>TBP).