2018 年 76 巻 7 号 p. 690-698
Extension of the π-system of porphyrins has attracted the interest of many chemists for applications such as light-emitting displays, organic thin-film electronics, and photosensitizers as a near-infrared dye. Herein we report our recent works on synthesis of aromatic ring-fused porphyrins and ring-expanded porphyrins with no meso-bridges. Porphyrins linked with aromatic ring through bicyclo[2.2.2]octadiene were prepared via the tetramerization and [3+1] porphyrin synthesis methods. The subsequent thermal conversion afforded ring-annelated porphyrins. Core-modified benzoporphyrins and π-extended BODIPYs were also obtained by the similar retro Diels-Alder strategy.
Ring-expanded porphyrins with no meso-bridges, cyclo[n]pyrroles(n=8 and 10), were selectively synthesized by using an oxidative coupling of the corresponding 2,2’-bipyrrole in the presence of appropriate template dianions. These octaphyrins and decaphyrin exhibited a markedly red-shifted strong L band at ca. 1,000-2,000 nm.