Efficient synthesis of 3,5-functionalized isoxazoles and isoxazolines<i>via</i>1,3-dipolar cycloaddition reactions of 1-propargyl- and 1-allylbenzotriazoles
作者:Alan R. Katritzky、Martin A. C. Button、Sergey N. Denisenko
DOI:10.1002/jhet.5570370616
日期:2000.11
3-Aryl-5-(benzotriazol-1-ylmethyl)- 10a-f and 3-p-methoxyphenyl-5-(α-benzotriazol-1-yl-α-ethoxymethyl)-isoxazole (13) were prepared in high yields by 1,3-dipolar cycloadditions of 1-propargyl-benzotriazole (5) and (α-ethoxypropargyl)benzotriazole (8), respectively, with nitrite oxides 3a-f (prepared in situ from benzohydroximoyl chlorides 2a-f). The benzotriazol-1-ylmethyl moiety was further elaborated
通过以下方法高产率地制备了3-芳基-5-(苯并三唑-1-基甲基)-10a-f和3-对甲氧基苯基-5-(α-苯并三唑-1-基-α-乙氧基甲基)-异恶唑(13) 1-炔丙基-苯并三唑(5)和(α-乙氧基炔丙基)苯并三唑(8)的1,3-偶极环加成分别与亚硝酸盐氧化物3a-f(由苯并氧肟基氯化物2a-f原位制备)。通过顺序锂化并与醛,烷基卤化物和迈克尔受体反应,进一步精制了苯并三唑-1-基甲基部分。使用1-烯丙基苯并三唑(6)和1-(α-乙氧基烯丙基)苯并三唑(7)的相似的1,3-环加成以优异的产率得到3,5-取代的异恶唑啉11b,f和12。