Transfer Hydrogenation Of Alkyl Levulinates To GVL Catalyzed By Iron Complexes

Lignocellulosic biomass is one of the most abundant renewable carbon resource of nature, which has huge potential in the preparation of fuels and chemicals and thus makes it an ideal substitute of fossil fuel resources. At present, researchers have developed many efficient conversion routes no matter with the original biomass feedstocks or corresponding derivatives, which set a sound foundation for larger and more dimensional development of biomass industry in the future. A series of biomass platform molecules could be prepared from lignocellulosic biomass through chemical or biological methods, such as furfural,5-hydroxymethylfurfural (5-HMF), formic acid, levulinic acid (LA), valeric acid, valerate and so on, which are important intermediate compounds in the chemical conversions of biomass and some of which themselves can serve as fuels or high value-added chemicals.γ-Valerolactone (GVL) is just such a compound, which can be fuel, food addictive, solvent and intermediate of organic synthesis. It occupies a decisive position in the area of biomass conversion and utilization so that it has attracted a wide attention of researchers. Up to now there are dozens of catalytic systems that can realize the transformation of lignocellulosic derivates to y-valerolactone and the conversion of levulinic acid or alkyl levulinates to y-valerolatone has been studied mostly, including homogeneous and heterogeneous catalytic systems. Compared to heterogeneous catalytic systems, homogeneous systems require lower amount of catalysts, reach higher catalytic efficiency and are easier to control. Whereas most homogeneous systems require noble metals such as ruthenium and iridium. Holding the concept of green chemistry and sustainable development, we tried to use non-noble metals to realize the synthesis of y-valerolactone. We reported the conversion of alkyl levulinates to y-valerolactone catalyzed by iron complex.In the first chapter of this paper, we introduce the concept of biomass and important catalytic reactions for biomass conversion. The properties, application and preparation of y-valerolactone are discussed emphatically. The preparation routes of GVL are summarized from the view of substrates and hydrogen sources emphatically.In the second chapter, we introduce iron catalyzed hydrogenation and transfer hydrogenation of carbonyl compounds briefly. We introduce iron complex catalyzed ethyl levulinate to y-valerolactone, including research background, reagents, experiment equipments, experiment methods, analytical methods, screening of reaction condition, experiment results and discussion.In conclusion, we reported a reaction system that can realize the conversion of ethyl levulinate to y-valerolactone over iron complex homogeneous catalyst, with isopropanol as hydrogen source. Also, we discussed and summarized the research background, process and meaning in detail.