Palladium-Catalyzed Formal Cross-Coupling of Diaryl Ethers with Amines: Slicing the 4-<i>O</i>
-5 Linkage in Lignin Models
作者:Huiying Zeng、Dawei Cao、Zihang Qiu、Chao-Jun Li
DOI:10.1002/anie.201712211
日期:2018.3.26
ether bonds (α‐O‐4, β‐O‐4, and 4‐O‐5 linkages) and other C−C bonds. Among the ether bonds, the bond dissociation energy of the 4‐O‐5 linkage is the highest and the most challenging to cleave. To date, 4‐O‐5 ether linkage model compounds have been cleaved to obtain phenol, cyclohexane, cyclohexanone, and cyclohexanol. The first example of direct formal cross‐coupling of diaryl ether 4‐O‐5 linkage models
木质素是地球上第二大最丰富的有机物质,是有价值的芳香族化学物质的未充分利用的可再生资源。为了将来芳香族化合物的可持续生产,非常需要将木质素转化为增值平台化学品,而不是使用基于化石的资源。木质素是通过三种类型的醚键(α-O-4,β-O-4和4-O-5键)和其他C-C键连接的芳香族聚合物。在醚键中,4-O-5键的键解离能最高,裂解难度最大。迄今为止,已将4-0-5醚键合模型化合物裂解以获得苯酚,环己烷,环己酮和环己醇。报道了第一个将二芳基醚4-0-5连接模型与胺直接形式交叉偶联的例子,