| Autor: |
Zhang, Zhenlei, Guo, Ge, Yang, Huaizhou, Csechala, Lina, Wang, Zhiwen, Cziegler, Clemens, Zijlstra, Douwe S., Lahive, Ciaran W., Zhang, Xiangping, Bornscheuer, Uwe T., Deuss, Peter J. |
| Zdroj: |
Angewandte Chemie; Dec2024, Vol. 136 Issue 49, p1-13, 13p |
| Abstrakt: |
Aromatic monomers obtained by selective depolymerization of the lignin β‐O‐4 motif are typically phenolic and contain (oxygenated) alkyl substitutions. This work reveals the potential of a one‐pot catalytic lignin β‐O‐4 depolymerization cascade strategy that yields a uniform set of methoxylated aromatics without alkyl side‐chains. This cascade consists of the selective acceptorless dehydrogenation of the γ‐hydroxy group, a subsequent retro‐aldol reaction that cleaves the Cα−Cβ bond, followed by in situ acceptorless decarbonylation of the formed aldehydes. This three‐step cascade reaction, catalyzed by an iridium(I)‐BINAP complex, resulted in 75 % selectivity for 1,2‐dimethoxybenzene from G‐type lignin dimers, alongside syngas (CO : H2≈1.4 : 1). Applying this method to a synthetic G‐type polymer, 11 wt % 1,2‐dimethoxybenzene was obtained. This versatile compound can be easily transformed into 3,4‐dimethoxyphenol, a valuable precursor for pharmaceutical synthesis, through an enzymatic catalytic approach. Moreover, the hydrodeoxygenation potential of 1,2‐dimethoxybenzene offers a pathway to produce valuable cyclohexane or benzene derivatives, presenting enticing opportunities for sustainable chemical transformations without the necessity for phenolic mixture upgrading via dealkylation. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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