Department of Chemical & Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585, Singapore.
Angew Chem Int Ed Engl. 2019 Apr 1;58(15):4934-4937. doi: 10.1002/anie.201814284. Epub 2019 Feb 14.
Funneling and functionalization of a mixture of lignin-derived monomers into a single high-value chemical is fascinating. Reported herein is a three-step strategy for the production of terephthalic acid (TPA) from lignin-derived monomer mixtures, in which redundant, non-uniform substitutes such as methoxy groups are removed and the desired carboxy groups are introduced. This strategy begins with the hydro-treatment of corn-stover-derived lignin oil over a supported molybdenum catalyst to selectively remove methoxy groups. The generated 4-alkylphenols are converted into 4-alkylbenzoic acids by carbonylation with carbon monoxide. The Co-Mn-Br catalyst then oxidizes various alkyl chains into carboxy groups, transforming the 4-alkylbenzoic acid mixture into a single product: TPA. For this route, the overall yields of TPA based on lignin content of corn stover could reach 15.5 wt %, and importantly, TPA with greater than 99 % purity was obtained simply by first decanting the reaction mixture and then washing the solid product with water.
将木质素衍生单体混合物转化为单一高价值化学品的缩合和功能化非常吸引人。本文报道了一种从木质素衍生单体混合物生产对苯二甲酸（TPA）的三步策略，其中去除了多余的、不均匀的取代基（如甲氧基），并引入了所需的羧基。该策略首先通过负载型钼催化剂对玉米秸秆衍生的木质素油进行加氢处理，选择性地去除甲氧基。生成的 4-烷基酚通过与一氧化碳羰基化反应转化为 4-烷基苯甲酸。然后，Co-Mn-Br 催化剂将各种烷基链氧化成羧基，将 4-烷基苯甲酸混合物转化为单一产物：TPA。对于这条路线，基于玉米秸秆木质素含量，TPA 的总收率可达 15.5wt%，重要的是，通过先将反应混合物倾析，然后用水洗涤固体产物，即可获得纯度大于 99%的 TPA。
