德国马克斯-普朗克研究所Tobias Ritter团队报道了硝酸还原使芳基重氮化学更安全。相关研究成果发表在2024年4月26日出版的《科学》。

芳基重氮盐仍然是有机合成中的主要成分，并且在很大程度上仍然是根据19世纪开发的方案制备的。由于与其他芳基（伪）卤化物通常无法实现的良好反应性，重氮化学需要继续发展。二硝基的方便挤出有助于获得所需的反应性，但也是安全问题的原因。自从发现这些试剂以来，爆炸时有发生，会导致事故。

该文中，研究人员报道了一种基于硝酸盐还原的重氮化学范式转变，使用硫代硫酸盐或二卤代铜盐作为电子供体，以避免重氮积累。由于硝酸盐还原是限速的，芳基重氮化合物是作为短暂的中间体生产的，这导致苯胺一步中进行更安全且通常更有效的脱氨基卤化。

附：英文原文

Title: Nitrate reduction enables safer aryldiazonium chemistry

Author: Javier Mateos, Tim Schulte, Deepak Behera, Markus Leutzsch, Ahmet Altun, Takuma Sato, Felix Waldbach, Alexander Schnegg, Frank Neese, Tobias Ritter

Issue&Volume: 2024-04-26

Abstract: Aryldiazonium salts remain a staple in organic synthesis and are still prepared largely in accord with the protocol developed in the 19th century. Because of the favorable reactivity that often cannot be achieved with other aryl(pseudo)halides, diazonium chemistry continues to grow. Facile extrusion of dinitrogen contributes to the desired reactivity but is also reason for safety concerns. Explosions have occurred since the discovery of these reagents and still result in accidents. In this study, we report a diazonium chemistry paradigm shift based on nitrate reduction using thiosulfate or dihalocuprates as electron donors that avoids diazonium accumulation. Because nitrate reduction is rate-limiting, aryldiazoniums are produced as fleeting intermediates, which results in a safer and often more efficient deaminative halogenation in a single step from anilines.

DOI: adn7006

Source: https://www.science.org/doi/10.1126/science.adn7006