Synthesis of Porphyrinquinone and Doubly-Fused Diporphyrin Quinone Through Oxidation of Diarylporphyrins Using a Hypervalent Iodine Compound

Treatment of a meso-diarylporphyrin with PhI(OAc)2 in the presence of BF3·OEt2 and propionic acid affords the corresponding porphyrinquinone in a high yield (91%). A novel quinone derived from meso-meso β-β doubly-fused diporphyrin was obtained as the sole byproduct (16% yield), which exhibited strong panchromatic absorption between 300 and 1000 nm. It had a low HOMO-LUMO gap owing to the expanded and low-symmetry π-planes.