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.