A Sequential Cycloisomerization/Oxidative Aromatization of 2-Propargyl-cyclohexenones for Direct Access to Substituted Benzofurans

Abstract

A new approach for the synthesis of benzofurans starting from non-aromatic precursors is reported. The reaction involves sequential DBU-mediated cycloisomerization for furanylation followed by benzene ring construction via oxidative aromatization in the presence of Oxone®. Atom- and pot-economy, simple reaction conditions, the straightforward preparation of starting materials and access to diverse substituted benzofurans are the major advantages of this reaction.

A Comprehensive Review on Benzofuran Synthesis Featuring Innovative and Catalytic Strategies

“…The Reddy group 107 proposed a novel methodology by employing nonaromatic precursors to obtain benzofuran derivatives 105 . They employed DBU (1,8-diazabicyclo(5.4.0)undec-7-ene) promoted cyclization (5-exo-dig cyclization) of 2-propargyl cyclohexenone 104 followed by oxidation-induced formation of a benzene ring utilizing oxone as an oxidant.…”