XY–ZH systems as potential 1,3-dipoles. Part 12. Mechanism of formation of azomethine ylides via the decarboxylative route from α-amino acids
XY–ZH systems as potential 1,3-dipoles. Part 12. Mechanism of formation of azomethine ylides via the decarboxylative route from α-amino acids
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XY-ZH 系统作为潜在的 1,3-偶极子第 12 部分。通过 α-氨基酸脱羧途径形成偶氮甲碱叶立德的机制。
DOI：
10.1039/p19880002703
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
D. Vipond
中科院分区：
文献类型：
--
作者：
R. Grigg;J. Idle;P. McMeekin;S. Surendrakumar;D. Vipond
研究了温度、溶剂和醛的种类对醛与三种α-氨基酸（环状仲α-氨基酸、含苄羧基的环状仲α-氨基酸和无环伯α-氨基酸）脱羧缩合生成偶氮甲碱叶立德的影响。从偶氮甲碱叶立德与N-甲基马来酰亚胺的环加合物的立体化学推断出（i）中的立体特异性反偶极形成和（ii）和（iii）中的温度依赖性立体选择性反偶极形成。这些结果被用来支持一个机制的计划，涉及损失的二氧化碳从中间体恶唑烷-5-酮在立体有择环逆转反应。
The effect of temperature, solvent, and type of aldehyde on the stereospecific or stereoselective formation of azomethine ylides by the decarboxylative condensation of aldehydes with three types of α-amino acids, (i) cyclic secondary α-amino acids, (ii) cyclic secondary α-amino acids with a benzylic carboxy group, and (iii) acyclic primary α-amino acids, has been studied. Stereospecific anti-dipole formation in (i) and temperature dependent stereoselective anti-dipole formation in (ii) and (iii) is inferred from the stereochemistry of cycloadducts of the azomethine ylides with N-methylmaleimide. These results are used to support a mechanistic scheme involving loss of carbon dioxide from intermediate oxazolidin-5-ones in a stereospecific cycloreversion reaction.