Ring Closure Reactions of 2,6-Diazaheptatrienyl Metal Compounds: Synthesis of 3-Aminoindole Derivatives and 14-Membered Macrocyclic Dimers
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- 作者：Benedikt Neue ; Ralph Reiermann ; Klaus Gerdes ; Roland Fr枚hlich ; Birgit Wibbeling ; Ernst-Ulrich W眉rthwein
- 刊名：Journal of Organic Chemistry
- 出版年：2011
- 出版时间：November 4, 2011
- 年：2011
- 卷：76
- 期：21
- 页码：8794-8806
- 全文大小：560K
- 年卷期：v.76,no.21(November 4, 2011)
- ISSN：1520-6904
文摘
2,6-Diazaheptatrienyl metal compounds 6鈥?/b>K+ are easily accessible from the corresponding diimines 6 by deprotonation using KO-t-Bu as base. According to quantum chemical calculations, they are, in comparison to other isomeric species with nitrogen atoms in other positions, highly reactive intermediates, which undergo in dilute solution at 50 掳C ring closure reactions to form 3-aminoindole derivatives 8/10. In contrast, in more concentrated solution at room temperature, the formation of 14-membered macrocyclces 13 as a result of formal dimerization is observed. The 3-aminoindole derivatives obtained in this work possess rare substitution patterns, and the macrocyclic compounds are essentially unknown. Two-fold vinylogous derivatives 7 give rise to tricyclic systems with 未-carboline backbone 12. The experimental results are interpreted using high-level DFT calculations with regard to the possible reaction mechanism and the nature of the transition state of the five-membered ring formation. The molecular structures in the solid state of all types of compounds were elucidated by X-ray diffraction.