关键词: 无氧化剂, 二芳基胺, 绿色溶剂, 肼类化合物

The N—N bond constitutes a fundamental structural motif in synthetic chemistry, ubiquitously present in organic compounds, natural products, and pharmaceutical agents. Beyond its structural significance, this bond demonstrates versatile functionalities in energy transfer systems, photoresponsive materials, and advanced dye technologies. Motivated by the critical importance of N—N bond formation, various synthetic methodologies have been explored. Among them, photocatalytic technology has stood out from numerous methods and become a highly regarded green organic synthesis means due to its mild conditions, environmental friendliness, and sustainable utilization. Based on this, this work reports the N—N self-coupling reaction of N-alkoxyamide and diarylamine compounds mediated by visible light. Employing commercially available Erythrosine Y disodium salt as the photosensitizer and ethyl acetate as the solvent, without metal catalysts, ligands and additives are required, a series of valuable functionalized hydrazines were provided at room temperature under air atmosphere with moderate to good yields. A total of 31 target compounds were synthesized, and the separation yield was up to 82%. Finally, the possible reaction mechanism was speculated through control experiments, hydrogen gas detection experiments, and relevant literature reports. This method not only features mild conditions and simple operation but also demonstrates good substrate universality, being applicable to various differently substituted benzene rings, aromatic heterocycles, and aliphatic amide substrates. Additionally, the target product can also be obtained with a separation yield of 49% under natural light conditions. It provides a simple, mild, and economical preparation approach for the synthesis of structurally complex hydrazine derivatives. The typical operational steps are as follows: In a 25 mL Schlenk tube, successively add N-alkoxyamide (0.2 mmol, 1 equiv.), Erythrosine Y disodium salt (2.5 mol%, 2.5% equiv.), and ethyl acetate (1 mL). Subject the reaction to irradiation at 10 W 413 nm LED for stirring and monitor the reaction progress using thin-layer chromatography (TLC). Once the starting materials are completely consumed, separate and purify the N—N self-coupling product using silica gel column chromatography.

Key words: no oxidant, diarylamine, green solvent, hydrazine compound