A versatile general approach to the synthesis of linearly annelated π-Extended porphyrins via 4,7-Dihydroisoindole derivatives

A convenient and straightforward approach to the synthesis of linearly annelated extended porphyrins of tetrabenzoand tetranaphthoporphyrin series was developed. 4,7-Dihydroisoindole and its benzoannelated derivative, being the closest stable precursors of unstable 2H-isoinsoles, are used in this method. Key features for this approach are its unprecedented synthetic versatility, tolerance for sensitive functional groups and the convenient introduction of meso-substituents. Aromatization of the annelated rings is conducted under mild conditions at the final stage of the synthesis. Tetraaryltetrabenzo-and tetranaphthoporphyrins are obtained using standard well-established procedures of porphyrin synthesis using common synthons.