Regio- and Stereoselective Synthesis of Spiropyrrolizidines and Piperazines through Azomethine Ylide Cycloaddition Reaction

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• 作者：Saoussen Haddad ; Sarra Boudriga ; Fran莽ois Porzio ; Armand Soldera ; Moheddine Askri ; Michael Knorr ; Yoann Rousselin ; Marek M. Kubicki ; Christopher Golz ; Carsten Strohmann
• 刊名：Journal of Organic Chemistry
• 出版年：2015
• 出版时间：September 18, 2015
• 年：2015
• 卷：80
• 期：18
• 页码：9064-9075
• 全文大小：733K
• ISSN：1520-6904

文摘

A series of original spiropyrrolizidine derivatives has been prepared by a one-pot three-component [3 + 2] cycloaddition reaction of (E)-3-arylidene-1-phenyl-pyrrolidine-2,5-diones, l-proline, and the cyclic ketones 1H-indole-2,3-dione (isatin), indenoquinoxaline-11-one and acenaphthenequinone. We disclose an unprecedented isomerization of some spiroadducts leading to a new family of spirooxindolepyrrolizidines. Furthermore, these cycloadducts underwent retro-1,3-dipolar cycloaddition yielding unexpected regioisomers. Upon treatment of the dipolarophiles with in situ generated azomethine ylides from l-proline or acenaphthenequinone, formation of spiroadducts and unusual polycyclic fused piperazines through a stepwise [3 + 3] cycloaddition pathway is observed. The stereochemistry of these N-heterocycles has been confirmed by several X-ray diffraction studies. Some of these compounds exhibit extensive hydrogen bonding in the crystalline state. To enlighten the observed regio- and stereoselectivity of the [3 + 2] cycloaddition, calculations using the DFT approach at the B3LYP/6-31G(d,p) level were carried out. It was found that this reaction is under kinetic control.