催化量碘代烷烃促进下合成3,5-二取代异噁唑啉

摘要

A new method for the preparation of 3 , 5-disubstituted isoxazolines using a catalytic amount of 1-iodopropane was developed and the optimization of the reaction conditions was obtained. The possible mechanism for the cycloaddition was suggested as followed:1-iodopropane was first oxidized by oxone into the hypervalent iodine intermediate, then it decomposed at once to form hypoiodous acid, the in situ generated hypoiodous acid reacted with oxime and alkene, and after an elimination of HI, the reaction provided the desired isoxazoline. The new method has some advantages such as mild reaction conditions, simple procedure and good yields.%研究了端基烯烃和醛肟在氧化剂过硫酸氢钾和催化量碘代烷烃作用下的[3+2]环合反应,合成了一系列具有良好产率及区域选择性的3,5-二取代异噁唑啉化合物。反应中,碘代烷烃先经过氧化分解产生了活泼的次碘酸,再依次与醛肟和烯烃经亲电加成反应生成五元杂环碘代中间体,该中间体通过消除反应得到3,5-二取代异噁唑啉化合物。考察了反应条件的影响,提出了可能的反应机理,为合成3,5-二取代异噁唑啉化合物提供了新方法。