Tetrahedron letters

Oxidative cyclization of aldazines with bis (trifluoroacetoxy) iodobenzene

Z Shang, J Reiner, J Chang, K Zhao

Index: Shang, Zhenhua; Reiner, John; Chang, Junbiao; Zhao, Kang Tetrahedron Letters, 2005 , vol. 46, # 15 p. 2701 - 2704

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Citation Number: 33

Abstract

The most common synthetic approach to 1,3,4-oxadiazoles involves cyclodehydration of 1,2-diacylhydrazines 1 (Scheme 1). Typically, this reaction is carried out by using thionyl chloride, 7 phosphorous oxychloride, 8 phosphorous pentoxide, 9 triphenylphosphine, 10 or trifluoromethane–sulfonic anhydride as the dehydrating agent. 11 Related preparations of oxadiazoles include the reaction of hydrazides with ketenylidene triphenylphosphorane, 12 base ...