Stereoselective synthesis of diazaspiro[5.5]undecane derivatives via base promoted [5+1] double Michael addition of N,N-dimethylbarbituric acid to diaryliedene acetones

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• 作者：Mohammad Shahidul Islam^a ; ¹ ; ^{mislam@ksu.edu.sa} ; Assem Barakat^a ; ^b ; ¹ ; ^{ambarakat@ksu.edu.sa} ; Abdullah Mohammed Al-Majid^a ; ¹ ; Hazem A Ghabbour^c ; ¹ ; Hoong-Kun Fun^c ; ^d ; ¹ ; M. Rafiq Siddiqui^a ; ¹
• 关键词：Cascade [5+1] cycloaddition ; Double Michael reaction ; Diethylamine catalysis ; Diazaspiro[5.5]undecane ; N ; N-Dimethylbarbituric acid diaryliedene acetone
• 刊名：Arabian Journal of Chemistry
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：10
• 期：1
• 页码：1-9
• 全文大小：972 K
• 卷排序：10

文摘

The nitrogen containing spiro-heterocycle is one of the privileged synthetic motif that constitutes various naturally occurring molecules and displays a broad range of pharmaceutical and biological activities. A new methodology was developed for the synthesis of 2,4-diazaspiro[5.5]undecane-1,3,5,9-tetraones spiro-heterocyclic derivatives via cascade cyclization of [5+1] double Michael addition reaction of N,N-dimethylbarbituric acid with the derivatives of diaryldivinylketones in the presence of diethylamine at ambient temperature. The developed protocol is highly capable of furnishing diazaspiro[5.5]undecane derivatives 3a–m in excellent yields (up to 98%), from easily accessible symmetric and non-symmetric divinylketones 2a–m, containing aryl and heteroaryl substituents. The diazaspiro-heterocyclic structure was mainly elucidated by NMR and X-ray crystallographic techniques. The single-crystal X-ray studies revealed that, the cyclohexanone unit of spirocycles often prefers a chair conformation rather than twisted conformation. The intermolecular hydrogen bonding and CArH⋯π, π–π stacking interactions driving forces are mainly responsible for the crystal packing.