延安大学韩波团队报道了铜N-杂环卡宾配合物催化硝基芳烃与氨硼烷的化学选择性转移加氢反应。相关研究成果发表在2024年3月26日出版的国际学术期刊《中国化学》。

该文中，研究人员提出了一种使用低催化剂负载（1mo%）的铜N-杂环卡宾络合物作为催化剂，和氨硼烷作为氢源来均相氢化硝基芳烃以制备苯胺的方法。以多种官能团为特征的硝基芳烃以高产率选择性地转化为相应的伯芳香胺。该方法可以很容易地扩大规模制备，并表现出与各种敏感官能团的兼容性，包括卤素、三氟甲基、氨基甲基、烯基、氰基、酯、酰胺和羟基。

值得注意的是，这种催化方法在基本药物化合物的合成中得到了应用。机理研究表明，原位生成的Cu-H物种可能作为活性中间体，还原途径涉及偶氮苯、1,2-二苯肼、亚硝苯和N-苯基羟胺等物种。

附：英文原文

Title: Chemoselective Transfer Hydrogenation of Nitroarenes with Ammonia Borane Catalyzed by Copper N-heterocyclic Carbene Complexes

Author: Hui Zhou, Hongmei Jiao, Xing Lu, Yuanyuan Gao, Zhiqiang Ren, Haojie Ma, Yuqi Zhang, Bo Han

Issue&Volume: 2024-03-26

Abstract: Herein, we present a method for the homogeneous hydrogenation of nitroarenes to produce anilines using low catalyst loading (1 mo%) of copper N-heterocyclic carbene complexes as the catalyst and ammonia borane as the source of hydrogen. A wide range of nitroarenes, featuring diverse functional groups, were selectively transformed into their corresponding primary aromatic amines with high yields. This process can be readily scaled up and exhibits compatibility with various sensitive functional groups, including halogen, trifluoromethyl, aminomethyl, alkenyl, cyano, ester, amide, and hydroxyl. Notably, this catalytic methodology finds application in the synthesis of essential drug compounds. Mechanistic investigations suggest that the in-situ-generated Cu-H species may serve as active intermediates, with reduction pathways involving species such as azobenzene, 1,2-diphenylhydrazine, nitrosobenzene, and N-phenylhydroxylamine.

DOI: 10.1002/cjoc.202400069

Source: https://onlinelibrary.wiley.com/doi/full/10.1002/cjoc.202400069