N—N键作为一种重要的化学键, 广泛存在于多种天然产物、有机功能材料和药物分子中, 并发挥着至关重要的作用. 开发了一种简便且高效的合成方法, 采用廉价易得的碘苯二乙酸(PIDA)作为氧化剂, 1,2-二氯乙烷作为溶剂, 60 ℃下实现了二芳基胺类化合物的N—N自偶联反应. 此过程无需金属催化剂和配体参与, 以优异的产率成功制备了肼类化合物. 该方法反应条件温和、操作简便、底物适用范围广, 尤其适用于具有大位阻和大分子取代基的二芳基胺类化合物. 这一策略为肼类化合物的合成提供了一种简便、温和且经济的新途径.

N—N bond, as an important chemical bond, is widely present in various natural products, organic functional materials, and drug molecules, and plays a crucial role. Although there were various synthetic methods for the formation of N—N bonds, the aforementioned reported coupling methods typically rely on expensive oxidants, metal catalysts, noble metal electrodes, expensive light sources, non-environmentally friendly solvents. Therefore, developing efficient, green, and widely applicable N—N bond construction methods has always been one of the research hotspots in the field of organic synthesis. A simple and efficient N—N self coupling reaction synthesis method based on the structural characteristics of diarylamine compounds was developed. This method uses inexpensive and readily available iodobenzene diacetic acid (PIDA) as an environmentally friendly oxidant, and 1,2-dichloroethane (DCE) as a reaction solvent to achieve selective oxidative self coupling between diarylamine molecules under mild conditions at 60 ℃, with a yield of 94%. The reaction system does not require any metal catalysts or additional ligands, making the operation simple and the post-treatment convenient. It effectively avoids the potential residual and toxicity issues associated with traditional metal reagents. Experimental results show that this strategy can efficiently construct a series of hydrazine compounds, including mono- and poly-substituted electron-donating groups, with excellent yields. Moreover, this reaction is particularly suitable for diarylamine substrates with bulky functional groups (such as tert-butyl, poly-substituted aromatic rings, and large fluorescent groups), achieving high yields and effectively solving the problem of difficult synthesis of diarylamines with bulky functional groups. It can still maintain good reactivity and chemical selectivity, demonstrating a wide range of substrate applicability. In summary, this study has established a novel strategy for constructing N—N bonds that is mild in reaction conditions, easy to operate, and economically feasible. This not only provides a greener and more efficient pathway for the synthesis of hydrazine compounds, but also offers new ideas and practical tools for the later modification and structural diversification of functional molecules and drug intermediates.