Highly efficient hydrogenation of biomass-derived levulinic acid to γ-valerolactone catalyzed by iridium pincer complexes

Catalytic reactions of gamma-valerolactone: A platform to fuels and value-added chemicals

“…Ru-or Ir-based homogeneous complex such as RuCl 2 (PPh 3 ) 3 , Ru(acac) 3 /PBu 3 , Ru(acac) 3 /P(nOct) 3 and [Ir(COE) 2 Cl] 2 catalystshave beenfrequently reported with good conversion of LA and high selectivity of GVL [52,55,56]. Some pioneered works have been done by Jooet al using water soluble ruthenium catalysts for the hydrogenation of LA using a Ru-complex catalyst based on mono-sulfonated triphenylphosphine [57].…”

Conversion of biomass platform molecules into fuel additives and liquid hydrocarbon fuels

“…Nevertheless, the main problem of these catalytic systems for practical use is the low turnover numbers (TONs) which in some cases do not exceed of 1600. 53 Recently Li et al 57 reported that Iridium trihydride catalyst bearing pyridine-based pincer ligands showed very high activity for levulinic acid hydrogenation to GVL achieving yields between 96-99% and TOFs of 71000, although the presence of strong homogeneous bases such as KOH or NaOH is required in order to achieve high yields of GVL.…”

An improved catalytic system for the reduction of levulinic acid to γ-valerolactone

“…EtOH, iPrOH). 16 Recently, similarly active (TOF = 2160 h −1 ) iridium complexes with 2,2′-bipyridine derivatives have been reported for the reduction of LA under mild reaction conditions in water using [LA] = 1 mol dm −3 initial concentration; 17 n.b. : in spite of the high activity, the final product concentration was less than 1 M and the water-removal step resulted in low energy efficiency of the process.…”