Sequential One-Pot Synthesis of 3-Arylbenzofurans from N-Tosylhydrazones and Bromophenol Derivatives

J Org Chem. 2020 Nov 6;85(21):13664-13673. doi: 10.1021/acs.joc.0c01835. Epub 2020 Oct 22.

Abstract

A divergent and efficient one-pot sequence allowing direct access to 3-arylbenzofuran derivatives has been developed. The process, involving N-tosylhydrazones and bromophenols, proceeds via a palladium-catalyzed Barluenga-Valdés cross-coupling, followed by an aerobic, copper-catalyzed, radical cyclization to form Csp2-Csp2 and O-Csp2 bonds. 3-Arylated benzofurans bearing various substituents were obtained with good to excellent yields (up to 90%). Mechanistic investigation strongly supports a radical process for the cyclization step.

Publication types

  • Research Support, Non-U.S. Gov't