中国科学院大连化物所王峰团队报道了木质素选择性芳基化用于生物质分馏和良性双酚。相关研究成果于2024年5月29日发表于国际一流学术期刊《自然》。

木质纤维素主要由疏水性木质素和亲水性多糖聚合物组成，是绿色生物炼制不可或缺的碳资源。当进行化学处理时，木质素由于阻碍下游加工的有害分子内和分子间交联而受到损害。目前的增值模式旨在通过阻断或稳定木质素5的脆弱部分来避免形成新的C–C键，称为缩合。尽管已经努力通过引入酚类添加剂来提高生物质的利用率，但利用木质素的缩合倾向仍然未经证实可以将木质素和碳水化合物增值为高价值产品。

该文中，研究人员通过使用具有高亲核性的木质素衍生酚，在催化芳基化途径中引导C–C键的形成来利用这种倾向。选择性缩合的木质素以接近定量的产率分离，同时保留其突出的可裂解β-醚单元，可以在涉及芳基迁移和转移氢化的串联催化过程中解锁。因此，木材中的木质素转化为良性双酚（34-48 wt%），这代表了其化石对应物的性能优势替代品。

纤维素脱木素纸浆和木聚糖木糖共同生产用于纺织纤维和可再生化学品。这种冷凝驱动的策略是对其他有前景的以单苯酚为导向的方法的补充，这些方法针对有价值的平台化学品和材料，从而有助于生物量的整体增值。

附：英文原文

Title: Selective lignin arylation for biomass fractionation and benign bisphenols

Author: Li, Ning, Yan, Kexin, Rukkijakan, Thanya, Liang, Jiefeng, Liu, Yuting, Wang, Zhipeng, Nie, Heran, Muangmeesri, Suthawan, Castiella-Ona, Gonzalo, Pan, Xuejun, Zhou, Qunfang, Jiang, Guibin, Zhou, Guangyuan, Ralph, John, Samec, Joseph S. M., Wang, Feng

Issue&Volume: 2024-05-29

Abstract: Lignocellulose is mainly composed of hydrophobic lignin and hydrophilic polysaccharide polymers, contributing to an indispensable carbon resource for green biorefineries1,2. When chemically treated, lignin is compromised owing to detrimental intra- and intermolecular crosslinking that hampers downstream process3,4. The current valorization paradigms aim to avoid the formation of new C–C bonds, referred to as condensation, by blocking or stabilizing the vulnerable moieties of lignin5,6,7. Although there have been efforts to enhance biomass utilization through the incorporation of phenolic additives8,9, exploiting lignin’s proclivity towards condensation remains unproven for valorizing both lignin and carbohydrates to high-value products. Here we leverage the proclivity by directing the C–C bond formation in a catalytic arylation pathway using lignin-derived phenols with high nucleophilicity. The selectively condensed lignin, isolated in near-quantitative yields while preserving its prominent cleavable β-ether units, can be unlocked in a tandem catalytic process involving aryl migration and transfer hydrogenation. Lignin in wood is thereby converted to benign bisphenols (34–48 wt%) that represent performance-advantaged replacements for their fossil-based counterparts. Delignified pulp from cellulose and xylose from xylan are co-produced for textile fibres and renewable chemicals. This condensation-driven strategy represents a key advancement complementary to other promising monophenol-oriented approaches targeting valuable platform chemicals and materials, thereby contributing to holistic biomass valorization.

DOI: 10.1038/s41586-024-07446-5

Source: https://www.nature.com/articles/s41586-024-07446-5