Tandem Synthesis of 2-Carboxybenzofurans via Sequential Cu-Catalyzed C-O Coupling and Mo(CO)6-Mediated Carbonylation Reactions

J Org Chem. 2020 Sep 4;85(17):11490-11500. doi: 10.1021/acs.joc.0c01620. Epub 2020 Aug 24.

Abstract

A modular tandem synthesis of 2-carboxybenzofurans from 2-gem-dibromovinylphenols has been established based on a sequence of Cu-catalyzed intramolecular C-O coupling and Mo(CO)6-mediated intermolecular carbonylation reactions. This protocol allowed one-step access to a broad variety of functionalized benzofuran-2-carboxylic acids, esters, and amides in good to excellent yields under Pd- and CO gas-free conditions.