Synthesis of Dibenzofurans Derivatives via Benzannulation of 2‐Nitrobenzofurans and Alkylidene Malononitriles
Dongdong Cao, Dingben Chen, Gang Chen, Hanjie Mo, Zhijun Xia, Kai‐bin Li, Jianguo Yang
Abstract
Abstract Although 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.
Topics & Concepts
ChemistryCombinatorial chemistryReaction conditionsOrganic chemistryCatalysisCatalytic C–H Functionalization MethodsMulticomponent Synthesis of HeterocyclesSynthesis of heterocyclic compounds