Chemoselective Reduction of Functionalized 5-Nitroisoxazoles: Synthesis of 5-Amino- and 5-[Hydroxy(tetrahydrofuran-2-yl)amino]isoxazoles
摘要:
Reduction by using SnCl2 of easily accessible 5-nitroisoxazoles substituted with an electron-withdrawing group (EWG) has been studied. Whereas the reaction in ethanol yielded 5-aminoisoxazoles, performing the reaction in tetrahydrofuran gave previously unknown 5-[hydroxy(tetrahydrofuran-2-yl)amino]isoxazoles. Both reduction procedures were optimized to afford the corresponding products in good to excellent yields. Some mechanistic details concerning the inclusion of the tetrahydrofuranyl moiety into the reaction product are discussed
5-Nitroisoxazoles in S<sub>N</sub>Ar reactions: access to polysubstituted isoxazole derivatives
作者:Dmitry A. Vasilenko、Sevastian E. Dronov、Dzianis U. Parfiryeu、Kirill S. Sadovnikov、Kseniya N. Sedenkova、Yuri K. Grishin、Victor B. Rybakov、Tamara S. Kuznetsova、Elena B. Averina
DOI:10.1039/d1ob00816a
日期:——
functionalization of the isoxazole ring via the reactions of aromatic nucleophilic substitution of the nitro group with various nucleophiles has been elaborated. The method features excellent chemical yields, easy operability of the reaction, mild reaction conditions and a broad scope of both 5-nitroisoxazoles and nucleophiles. A synthetic approach to 3,5- and 3,4,5-substituted isoxazoles via the sequential