摘要/Abstract

在离子液体[Cpmim]Cl中，利用O-甲氧基炔酮肟醚为反应底物，以5 mol% Pd（TFA）₂为催化剂，2 equiv.CuBr₂为溴源，以中等至优良产率（68%～90%）合成了系列4-溴代异噁唑衍生物，其结构均经¹H NMR，¹³C NMR及HRMS确证.该反应具有产率高、底物适用范围广、原子经济性高等优点.此外，生成的产物通过进一步的修饰与转化可以衍生为结构复杂的、具有潜在生物活性的异噁唑活性分子.
关键词: 离子液体, 钯催化, O-甲氧基炔酮肟醚, 4-溴代异噁唑
An efficient palladium-catalyzed protocol for the synthesis of 4-bromoisoxazoles derivatives in moderate to good yields from readily available O-methyl oximes in basic ionic liquid has been developed. Their structures were confirmed by ¹H NMR, ¹³C NMR and HRMS. This cascade cyclization/bromination process provides a novel route for directly accessing 4-bromoisoxazole in good to excellent yields and good functional group tolerance with high atom efficiency. Notably, the current methodology could also be conveniently applied to the synthesis of isoxazoles naturally occurring biologically active frameworks.
Key words: ionic liquid, palladium catalysis, 2-alkynone O-methyloxime, 4-bromoisoxazole


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