Selective Production of Diethyl Maleate via Oxidative Cleavage of Lignin Aromatic Unit

Abstract

A highly efficient process for producing bulk chemical diethyl maleate is achieved with polyoxometalate ionic liquids from a cleavage lignin aromatic unit with high yield and selectivity, which is ascribed to the intensive synergistic effect between the acidic depolymerization, oxidative aromatic ring cleavage, and in situ esterification. This work offers new insight into the versatile petroleum-based chemical production from renewable resources.

Product‐oriented Direct Cleavage of Chemical Linkages in Lignin

“…The reaction mechanism involved lignin depolymerization, aromatic ring cleavage, and subsequent formation of final products. Li and co‐workers devised a highly effective catalytic system to synthesis diethyl maleate with high yield and selectivity of 72.7 % from lignin over the polyoxometalate ionic liquid of [BSmim]CuPW 12 O 40 . The process is combined with acid‐catalyzed lignin depolymerization into C9 phenylpropane and sequential selective oxidation of lignin aromatic units (Scheme ).…”

“…Aromatic units are extremely stable and hardly interrupted because of the conjugated C=C bonds . Oxidative cleavage of lignin is a suitable strategy to disrupt aromatic units and produce a series of aliphatic acids .…”

Selective conversion of biomass catalyzed by ionic liquids

“…因此, 木质素是 一种天然的表面活性剂 [33,48] . 鉴于此, 本课题组构建 了系列基于木质素自表面活性的乳液反应体系, 如 以丁磺酸基咪唑离子液体为催化剂, 实现了木质素 分子中的特征化学键的选择性断裂(图 4 所示) [49] Figure 5 Conversion of lignin to aromatic chemicals and their derivatives catalyzed by ionic liquid [49][50][51] 出于对定向催化木质素转化制备芳香族化学品 以及离子液体催化剂回收困难的考虑, 课题组还开 发了系列高效且可重复使用的离子液体催化剂, 用 于选择性催化木质素定向转化(图 5 所示) [50,51] [50] . 木质素结构单元定量分析结果表明, 蔗渣木质素 中 86 wt%的 H 结构单元可被定向转化 [50] , 进而采用…”

One-pot conversion of dihydroxyacetone into ethyl lactate by Zr-based catalysts

“…Lignocellulosic biomass, the largest sustainable carbon resource, is recognized as the most promising alternative for producing bio-fuels and bio-based platform chemicals such as levulinic acid, 5-hydroxymethyl furfural, formic acid and ethyl lactate (EL). [1][2][3] Among them, EL obtained from biomass renery has attracted growing interest due to its wide application. For example, EL could be applied in food additives, pharmaceuticals, and cosmetics for its low toxicity.…”