Bai Jing, Li Hao, Zhu Yuting, Zhu Yiping, Wang Chenguang, Wang Haiyong, Liao Yuhe
School of Mechanical and Power Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China.
School of Chemical Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China.
ChemSusChem. 2023 Nov 8;16(21):e202300558. doi: 10.1002/cssc.202300558. Epub 2023 Aug 17.
Although the multiple functional groups in biomass offer notable chances for producing high-value chemicals, most of the current studies focused on the (deep) defunctionalization of biomass and its derivates. Herein, we present a catalytic approach to valorize birch wood lignin with maintaining the methoxy and hydroxy groups in the final product (i. e., 2,6-dimethoxy-p-aminophenol), which has applications in different sectors such as pharmaceuticals. The proved approach involves four steps with a high yield (19.8 wt % on the basis of used lignin) to 2,6-dimethoxy-p-aminophenol. The native lignin in birch wood was first converted using alkaline aerobic oxidation in the presence of copper ions toward high-yield syringaldehyde, which was then selectively oxidized toward 2,6-dimethoxy-1,4-benzoquinone using H O and V O . Oximation of 2,6-dimethoxy-1,4-benzoquinone can selectively form 2,6-dimethoxy-1,4-benzoquinone-4-oxime, which can be quantitatively hydrogenated toward 2,6-dimethoxy-p-aminophenol. This work highlights the unique potential of biomass and its derivates for the sustainable production of high-value products with exploring the value of inherent functional groups.
尽管生物质中的多个官能团为生产高价值化学品提供了显著机会，但目前大多数研究集中在生物质及其衍生物的（深度）去官能化上。在此，我们提出了一种催化方法，在最终产物（即2,6-二甲氧基对氨基苯酚）中保留甲氧基和羟基的情况下，将桦木木素转化为高附加值产品，该产品在制药等不同领域有应用。所验证的方法包括四个步骤，以高产率（基于所用木素为19.8 wt%）得到2,6-二甲氧基对氨基苯酚。桦木中的天然木素首先在铜离子存在下通过碱性好氧氧化转化为高产率的紫丁香醛，然后使用H₂O₂和V₂O₅将其选择性氧化为2,6-二甲氧基-1,4-苯醌。2,6-二甲氧基-1,4-苯醌的肟化可以选择性地形成2,6-二甲氧基-1,4-苯醌-4-肟，其可以定量氢化为2,6-二甲氧基对氨基苯酚。这项工作突出了生物质及其衍生物在探索固有官能团价值以可持续生产高价值产品方面的独特潜力。
