华南理工大学张珉研究团队报道了通过单原子钴催化剂多组分还原偶联选择性获得功能化γ-内酰胺。相关研究成果于2024年3月21日发表在国际顶尖学术期刊《美国化学会杂志》。

尽管α-羟基-γ-内酰胺在许多领域具有重要意义，但直接和多样化合成它们的困难对其实际应用构成了实质性障碍。

该文中，研究人员设计了一种具有原子分散钴位点的氮和TiO₂共掺杂石墨碳负载材料（CoSA-N/NC-TiO₂），该材料被成功地用作多功能催化剂，以建立一种由廉价且丰富的硝基（杂）芳烃、醛和H₂O与炔酸酯，直接构建α-羟基-γ-内酰胺的通用方法。

操作简单、底物和功能兼容性广（>100个实例）、高阶和原子效率、良好的选择性，和优异的催化剂可重复使用性等显著特征突出了这种新型催化转化的实用性。机理研究表明，活性CoN₄物种和掺杂剂对关键酸掩蔽硝酮的形成表现出协同作用。它们随后亲核添加到炔酸酯中，依次还原、烯基水合和分子内酯氨解，从而提供所需的产物。

该这项工作中，还原中断导致新反应路线的概念，将为通过合理的催化剂设计进一步开发有用的转化打开大门。

附：英文原文

Title: Multicomponent Reductive Coupling for Selective Access to Functional γ-Lactams by a Single-Atom Cobalt Catalyst

Author: Jia-Lu Sun, Huanfeng Jiang, Pierre. H. Dixneuf, Min Zhang

Issue&Volume: March 21, 2024

Abstract: Despite their significant importance to numerous fields, the difficulties in direct and diverse synthesis of α-hydroxy-γ-lactams pose substantial obstacles to their practical applications. Here, we designed a nitrogen and TiO2 co-doped graphitic carbon-supported material with atomically dispersed cobalt sites (CoSA-N/NC-TiO2), which was successfully applied as a multifunctional catalyst to establish a general method for direct construction of α-hydroxy-γ-lactams from cheap and abundant nitro(hetero)arenes, aldehydes, and H2O with alkynoates. The striking features of operational simplicity, broad substrate and functionality compatibility (>100 examples), high step and atom efficiency, good selectivity, and exceptional catalyst reusability highlight the practicality of this new catalytic transformation. Mechanistic studies reveal that the active CoN4 species and the dopants exhibit a synergistic effect on the formation of key acid-masked nitrones; their subsequent nucleophilic addition to the alkynoates followed by successive reduction, alkenyl hydration, and intramolecular ester ammonolysis delivers the desired products. In this work, the concept of reduction interruption leading to new reaction route will open a door to further develop useful transformations by rational catalyst design.

DOI: 10.1021/jacs.4c00547

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c00547