Subbotina Elena, Souza Layra Rodrigues, Zimmerman Julie, Anastas Paul
Department of Chemistry, Yale University, 225 Prospect St, New Haven, CT, USA.
Department of Fibre and Polymer Technology, Wallenberg Wood Science Center, KTH Royal Institute of Technology, Teknikringen 56, 100 44, Stockholm, Sweden.
Nat Commun. 2024 Jul 13;15(1):5892. doi: 10.1038/s41467-024-49812-x.
Lignin is the largest source of renewable aromatics on earth. Despite numerous techniques for lignin depolymerization into mixtures of valuable monomers, methods for their upgrading into final products are scarce. The state of the art upgrading methods generally rely on catalytic funneling, requiring high temperatures, catalyst loadings and hydrogen pressure, and lead to the loss of functionality and bio-based carbon content. Here an alternative approach is presented, whereby the target monomers are selectively converted in unpurified mixtures into easily separable final products under mild conditions. We use reductive catalytic fractionation of wood to convert lignin into iso-eugenol and propenyl syringol enriched oil followed by an olefin metathesis to yield bisphenols and butene-2, thus, valorizing all bio-based carbons. To further demonstrate the synthetic utility of the obtained bisphenols we converted them into polyesters with a high glass transition temperature (T = 140.3 °C) and thermal stability (Td = 330 °C).
木质素是地球上可再生芳烃的最大来源。尽管有许多将木质素解聚为有价值单体混合物的技术，但将这些单体升级为最终产品的方法却很少。目前的升级方法通常依赖于催化漏斗法，需要高温、催化剂负载量和氢气压力，并且会导致官能团和生物基碳含量的损失。本文提出了一种替代方法，即在温和条件下，将目标单体在未纯化的混合物中选择性地转化为易于分离的最终产品。我们采用木材的还原催化分馏法，将木质素转化为富含异丁香酚和丙烯基丁香酚的油，然后通过烯烃复分解反应生成双酚和2-丁烯，从而使所有生物基碳都得到增值。为了进一步证明所得双酚的合成效用，我们将它们转化为具有高玻璃化转变温度（T = 140.3℃）和热稳定性（Td = 330℃）的聚酯。
