A Synthetic Approach to β-Functionalized Naphtho[2,3]porphyrins

A concise synthetic method has been developed to access functionalized naphtho[2,3]porphyrins through combining two sequence reactions involving a Heck–electrocyclization–aromatization sequence and a Wittig–Knovenegal sequence. Using this method, mononaphtho[2,3]porphyrin ( NP-1 ), opp -dinaphtho[2,3]porphyrin ( NP-2 ), and push–pull naphtho[2,3]porphyrin ( NP-3 ) have been prepared. These naphtho[2,3]porphyrins displayed interesting optical and electrochemical properties. Excellent efficiencies of singlet oxygen generation were obtained for these naphtho[2,3]porphyrins.