Ruthenium-catalyzed solvent-free conversion of furfural to furfuryl alcohol

Bidentate phosphine-modified Ru-based homogeneous catalyst systems were developed for solvent-free conversion of furfural to furfuryl alcohol as a versatile biomass-based C-5-platform molecule. The effect of the ligand structure and ligand concentration, the operating pressure and the reaction temperature on the catalyst's activity were studied in details. Under optimized conditions complete conversion of furfural to furfuryl alcohol was achieved in the absence of any added solvent and without any by-product formation. The maximum turnover frequency (6273 h(-1)) and 100% atom economy were obtained by using homogeneous Ru/Ph2P(CH2)(4)PPh2 catalyst, which was recyclable for twelve consecutive runs without affecting the catalytic performance of the catalyst.