One-Pot Phosphine-Catalyzed Syntheses of Quinolines
详细信息 查看全文
- 作者：San Khong ; Ohyun Kwon
- 刊名：The Journal of Organic Chemistry
- 出版年：2012
- 出版时间：September 21, 2012
- 年：2012
- 卷：77
- 期：18
- 页码：8257-8267
- 全文大小：488K
- 年卷期：v.77,no.18(September 21, 2012)
- ISSN：1520-6904
文摘
In this study we developed an efficient one-pot procedure for the preparation of 3-substituted and 3,4-disubstituted quinolines from stable starting materials (activated acetylenes reacting with o-tosylamidobenzaldehydes and o-tosylamidophenones, respectively) under mild conditions. The reaction appears to operate under a general base catalysis mechanism, instigated by the 尾-phosphonium enoate 伪-vinyl anion generated in situ through nucleophilic addition of PPh3 to the activated alkyne. Michael addition of the deprotonated tosylamides to the activated alkynes and subsequent rapid aldol cyclization led to the formation of labile N-tosyldihydroquinoline intermediates. Driven by aromatization, detosylation of the dihydroquinoline intermediates occurred readily in the presence of dilute aqueous HCl to give the final quinoline products.