1,3-DIPOLAR CYCLOADDITIONS OF 2-ETHOXY-1-AZETINES AND 2-(ETHYLTHIO)-1-AZETINES WITH NITRILE OXIDES, NITRILE YLIDES AND NITRILIMINES - AN UNEXPECTED 1,2,4-TRIAZOLE FORMATION
1,3-DIPOLAR CYCLOADDITIONS OF 2-ETHOXY-1-AZETINES AND 2-(ETHYLTHIO)-1-AZETINES WITH NITRILE OXIDES, NITRILE YLIDES AND NITRILIMINES - AN UNEXPECTED 1,2,4-TRIAZOLE FORMATION
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DOI：
10.1016/s0040-4020(01)85755-0
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发表时间：
1993-05-14
期刊：
影响因子：
2.1
通讯作者：
WESTWOOD, R
中科院分区：
文献类型：
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作者：
HEMMING, K;LUHESHI, ABN;WESTWOOD, R
2-乙氧基-和2-（乙硫基）-1-氮杂环丁烷容易与腈氧化物和腈叶立德进行1，3-偶极环加成，得到稳定的4，5-双环环加合物。然而，使用次氮亚胺，根据次氮亚胺N-取代基的性质，形成预期的1，3-偶极环加合物和/或意外的开环产物，即1，2，4-三唑。与此相反，氮杂环丁烷不能与腈硫化物，甲亚胺叶立德，硝酮，芳基叠氮化物，和各种dienes. X-射线晶体学数据的腈氧化物，腈叶立德，和腈亚胺环加合物，并在1，2，4-三唑，提出。还提供了三唑形成的机械原理。
2-Ethoxy- and 2-(ethylthio)-l-azetines readily undergo 1,3-dipolar cycloadditions with nitrile oxides and nitrile ylides to give stable 4,5-bicyclic cycloadducts. With nitrilimines, however, the expected 1,3-dipolar cycloadducts and/or unexpected ring-opened products, namely 1,2,4-triazoles, are formed depending on the nature of the nitrilimine N-substituent. In contrast, the azetines fail to react with nitrile sulphides, azomethine ylides, nitrones, aryl azides, and various dienes.X-ray crystallographic data on the nitrile oxide, nitrile ylide, and nitrilimine cycloadducts, and on the 1,2,4-triazoles, are presented. Also a mechanistic rationale for triazole formation is offered.