By using lignin model compounds with relevant key characteristic structural features, the reaction pathways of α-O-4 aryl ether linkages under hydrothermal conditions are elucidated. Experimental results and computational modeling suggest that the α-O-4 linkages in lignin undergo catalyzed hydrolysis and elimination to give phenolic and alkenylbenzene derivatives as major products in subcritical water. The decreased relative permittivity of water at these high temperatures and pressures facilitates the elimination reactions. The alkyl group on the α-carbon and the methoxy groups on the phenyl rings both have positive effects on the rate of conversion of α-O-4 linkages in native lignin.

中文翻译：

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木质素中α-O-4芳醚键的水热液化

通过使用具有相关关键特征结构特征的木质素模型化合物，阐明了在水热条件下α-O-4芳基醚键的反应途径。实验结果和计算模型表明，木质素中的α-O-4键经过催化水解和消除，从而在次临界水中以酚和烯基苯衍生物为主要产物。在这些高温和高压下水相对介电常数的降低促进了消除反应。α-碳上的烷基和苯环上的甲氧基均对天然木质素中α-O-4键的转化率产生积极影响。