1,3-dipolar cycloadditions of 2-Ethoxy- and 2-(ethylthio)-1-azetines with nitrile oxides, nitrile ylides and nitrilimines: An unexpected 1,2,4-triazole formation.

Karl Hemming, Abdul Bassett N. Luheshi, Alan D. Redhouse, Robert K. Smalley, J. Robin Thompson, Peter D. Kennewell, R. Westwood

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

2-Ethoxy- and 2-(ethylthio)-1-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.

Original languageEnglish
Pages (from-to)4383-4408
Number of pages26
JournalTetrahedron
Volume49
Issue number20
DOIs
Publication statusPublished - 1 Jan 1993
Externally publishedYes

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