Hydrogenation of Biomass-Derived Levulinic Acid into γ‑Valerolactone Catalyzed by Palladium Complexes
datasetposted on 06.03.2015, 00:00 by Carmen Ortiz-Cervantes, Marcos Flores-Alamo, Juventino J. García
The selective catalytic hydrogenation and cyclization of levulinic acid (LA) into valuable γ-valerolactone (GVL) catalyzed by different palladium compounds was achieved in water under mild conditions with high yields. Either formic acid (FA) or molecular hydrogen (H2) was used as a hydrogen source. The precatalyst [(dtbpe)PdCl2] (dtbpe = 1,2-(bis-di-tert-butylphosphino)ethane) (1) was highly active in the processes of LA hydrogenation (TON of 2100 and TOF of 2100 h–1) and in the dehydrogenation of formic acid to produce H2 and carbon dioxide. The catalytically active complexes [(dtbpe)Pd(H)Cl)] (2) and [(dtbpe)2Pd2(μ-H)3]+ (3) and the catalytically inactive complex [(dtbpe)2Pd2(μ-H) (μ-CO)]+ (4) all formed in situ and were identified as species resulting from FA decomposition.