Proline-Catalyzed Direct Inverse Electron Demand Diels–Alder Reactions of Ketones with 1,2,4,5-Tetrazines
作者:Hexin Xie、Liansuo Zu、Hanine R. Oueis、Hao Li、Jian Wang、Wei Wang
DOI:10.1021/ol800417q
日期:2008.5.1
An organocatalytic direct inverse electron demand Diels-Alder reaction of ketones with 1,2,4,5-tetrazines has been developed. The process is efficiently catalyzed by proline to give Diels-Alder adducts pyridazines in high yields.
A new and straightforward procedure is described for the preparation of highly substituted pyridines and pyridazines. The method involves a Diels-Alder/retro-Diels-Alder sequence leading to dihydropyridine or related intermediates, which can be aromatized to pyridines and pyridazines by treatment with silica gel. The value of this procedure has been demonstrated with a one-step -synthesis of an E-ring-modified
描述了一种新的、直接的方法来制备高度取代的吡啶和哒嗪。该方法涉及 Diels-Alder/retro-Diels-Alder 序列,导致二氢吡啶或相关中间体,可以通过硅胶处理将其芳构化为吡啶和哒嗪。该程序的价值已通过 E 环修饰的类固醇的一步合成得到证明。
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