Tandem reaction of propargyl alcohols and N-tosyl hydroxylamine: switchable synthesis of 2,5-dihydroisoxazoles and 4-halo-2,5-dihydroisoxazoles

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• 作者：Yuanxun Zhu ; Guangwei Yin ; Lang Sun ; Ping Lu ; Yanguang Wang
• 关键词：Propargylic alcohols ; Hydroxylamines ; Allenamides ; Dihydroisoxazoles ; Tandem reactions
• 刊名：Tetrahedron
• 出版年：2012
• 出版时间：9 December, 2012
• 年：2012
• 卷：68
• 期：49
• 页码：10194-10200
• 全文大小：591 K

文摘

2,5-Dihydroisoxazoles, 4-iodo-2,5-dihydroisoxazoles, and 4-bromo-2,5-dihydroisoxazoles were efficiently constructed from propargylic alcohols and N-tosyl hydroxylamine using ytterbium triflate, iodine and N-bromosuccinimide, respectively. N-sulfonylallenamide is postulated to be the key intermediate for these tandem transformations. Moreover, the resulting 4-iodo-2,5-dihydroisoxazoles could be elaborated by palladium-catalyzed carbonylation to generate 4-methoxycarbonyl-4,5-dihydroisoxazoles.