TY - JOUR
T1 - 1,3-dipolar cycloadditions of 2-Ethoxy- and 2-(ethylthio)-1-azetines with nitrile oxides, nitrile ylides and nitrilimines
T2 - An unexpected 1,2,4-triazole formation.
AU - Hemming, Karl
AU - Luheshi, Abdul Bassett N.
AU - Redhouse, Alan D.
AU - Smalley, Robert K.
AU - Thompson, J. Robin
AU - Kennewell, Peter D.
AU - Westwood, R.
PY - 1993/1/1
Y1 - 1993/1/1
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=0027279034&partnerID=8YFLogxK
U2 - 10.1016/S0040-4020(01)85755-0
DO - 10.1016/S0040-4020(01)85755-0
M3 - Article
AN - SCOPUS:0027279034
VL - 49
SP - 4383
EP - 4408
JO - Tetrahedron
JF - Tetrahedron
SN - 0040-4020
IS - 20
ER -