Access to Electron‐Rich Dibenzofurans through NBu4OAc‐Mediated Palladium Catalysis

Abstract

AbstractDibenzofuran and its derivatives are ubiquitous and important medicinal and natural products. Many contain electron‐rich aryl rings. Forming the key intramolecular Ar−Ar bond using traditional cross‐coupling is difficult. The C−H functionalisation (C−H activation) approach is, in principle, far more useful. However, we previously found that the well‐established conditions, which promote C−H functionalisation through Concerted Metalation‐Deprotonation (CMD), proved unsatisfactory. Herein, we report a Pd‐catalysed C−H functionalisation protocol that works with electron‐rich arenes. We use tetrabutylammonium acetate (NBu4OAc), which we suspect can act as base, ligand and solvent, rendering this protocol a simple and efficient route to electron‐rich dibenzofurans.