The electrophilic halogenation of arenes is perhaps the simplest method to prepare aryl halides, which are important structural motifs in agrochemicals, materials, and pharmaceuticals. However, the nucleophilicity of arenes is weakened by the electron-withdrawing substituents, whose electrophilic halogenation reactions usually require harsh conditions and lead to limited substrate scopes and applications
transformations. Classical electrophilic aromatic halogenationusing molecular halogens and Lewis/Brønsted acid activators is still a promising synthetic tool; however, it suffers from handling difficulties, low selectivity, and limited functional group tolerance. We herein introduce carborane-based Lewis base catalysts for aromatic halogenationusing -halosuccinimides. The developed reaction system
Isoxazolderivate, Verfahren zu ihrer Herstellung, diese Verbindungen enthaltende Arzneimittel und bei dem Verfahren benötigte Zwischenprodukte
申请人:HOECHST AKTIENGESELLSCHAFT
公开号:EP0012435A2
公开(公告)日:1980-06-25
Isoxazolderivate und Verfahren zu ihrer Herstellung werden beschrieben. Die Verbindungen wirken antirheumatisch, antiphlogistisch, analgetisch und antipyretisch und können als Arzneimittel verwendet werden.
Phase‐Transfer Catalysis for Electrochemical Chlorination and Nitration of Arenes
作者:Yingdong Duan、Sanzhong Luo
DOI:10.1002/anie.202319206
日期:2024.4.22
A unique biphasic electrochemical reaction, wherein tetrabutylammonium (TBA+) salts play a dual role as both electrolyte and phasetransfer catalysts, was developed to furnish chlorination and nitration of aromaticcompoundsusing cheap inorganic salts with up to 98 % yield, shorter reaction time and higher Faradaic efficiency.