Tandem Hydrogenation and Hydrolytic Ring-Opening of Benzofurans to Hydroxyalkyl-Substituted Cyclohexanols Catalyzed by Supported Ruthenium Nanoparticles

Abstract

A new synthetic route toward 1,2-hydroxyalkyl-substituted cyclohexanols via catalytic tandem hydrogenation–hydrolytic ring-opening of benzofurans in water is reported. Catalysts based on Ru nanoparticles immobilized on a hydrothermally-stable supported ionic liquid phase (Ru@SILPAC) enable the conversion of benzofuran derivatives into valuable polyols (40–68% isolated yields) using hydrogen and water as the only reactants. Mechanistic investigations identify 2,3-dihydrobenzofuran as a key intermediate, consistent with a sequential pathway involving partial hydrogenation followed by hydrolytic ring opening. The Ru@SILPAC catalyst is recyclable and exhibits high stability under hydrothermal conditions. This work introduces a new transformation of benzofurans and provides a catalytic route to oxygenated carbocyclic scaffolds in line with green chemistry principles.