Conjugate Additions, Aza-Cope, and Dissociative Rearrangements and Unexpected Electrocyclic Ring Closures in the Reactions of 2-(2-Pyrrolidinyl)-Substituted Heteroaromatic Systems with Acetylenic Sulf

详细信息    查看全文

• 作者：Mitchell H. Weston ; Masood Parvez ; Thomas G. Back
• 刊名：Journal of Organic Chemistry
• 出版年：2010
• 出版时间：August 6, 2010
• 年：2010
• 卷：75
• 期：15
• 页码：5402-5405
• 全文大小：779K
• 年卷期：v.75,no.15(August 6, 2010)
• ISSN：1520-6904

文摘

The reactions of 2-heteroaryl-substituted pyrrolidines with acetylenic sulfones proceeded via two pathways. The first involves conjugate addition of the pyrrolidine to the acetylenic sulfone to afford a zwitterion, followed by dissociation of the C−N bond and recombination of the resulting carbocation and vinyl anion to afford the corresponding azepine derivative. The second comprises a cascade of conjugate addition, aza-Cope rearrangement and anionic 6π electrocyclic ring-closure steps. The stability of the carbocation intermediate formed by C−N cleavage determines the dominant pathway.