化学
异构化
级联
烷基化
组合化学
有机化学
催化作用
色谱法
作者
Takeo Sakai,Fujio Saito,Kota Hosoe,Yoshihiro Mori
出处
期刊:Tetrahedron
[Elsevier]
日期:2024-01-01
卷期号:: 133851-133851
标识
DOI:10.1016/j.tet.2024.133851
摘要
Alkylation–cyclization–isomerization–3-aza-Cope cascade is a powerful method for constructing fused nitrogen heterocycles bearing tetrasubstituted carbons. Despite this, the use of pyrrolidines as starting substrates in these reactions remains limited. In our study, we conducted a detailed analysis of the cascade product using OTBS-substituted pyrrolidine. Our findings revealed that the main product was a nine-five-membered bicyclic enamine, which formed through a 3-aza-Cope rearrangement from syn-vinylammonium. Further, our comprehensive DFT calculations of the transition states of the 3-aza-Cope rearrangement from both anti- and syn-dienolates and vinylammoniums demonstrated that the rearrangement from syn-vinylammonium was more favorable. This preference stems from its progression through a late transition state that minimizes distortion of the pyrrolidine ring. These findings enhance our understanding of the mechanism and facilitate the prediction of outcomes of future cascade reactions.
科研通智能强力驱动
Strongly Powered by AbleSci AI