Synthesis of Dibenzofurans Derivatives via Benzannulation of 2‐Nitrobenzofurans and Alkylidene Malononitriles

Abstract

AbstractAlthough various methods for the preparation of dibenzofurans are available, an efficient, general synthesis of dibenzofurans from benzofurans remains an unsolved problem. Herein, we provide the first benzannulation of readily prepared 2‐nitrobenzofurans with alkylidene malononitriles. This methodology enables facile assembly of a wide variety of highly functionalized dibenzofurans in moderate to excellent yields under metal‐free conditions. Gram‐scale synthesis and further elaborations of the product were succesfully performed, demonstrating synthetic utility of this method.