One-Pot Phosphine-Catalyzed Syntheses of Quinolines
摘要:
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 beta-phosphonium enoate alpha-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.
An efficient 3-acylquinoline synthesis from acetophenones and anthranil<i>via</i>C(sp<sup>3</sup>)–H bond activation mediated by Selectfluor
作者:Yejun Gao、Robert C. Hider、Yongmin Ma
DOI:10.1039/c9ra01481k
日期:——
method for the synthesis of 3-functionalized quinolines from commercially available acetophenones and anthranil has been described. Selectfluor propels the C(sp3)–H bond activation of the acetophenones and aza-Michael addition of anthranil resulting in annulated 3-acylquinolines in moderate to high yields. DMSO acts not only as a solvent but also as a one carbon donor in the reaction.
One-Pot Phosphine-Catalyzed Syntheses of Quinolines
作者:San Khong、Ohyun Kwon
DOI:10.1021/jo3015825
日期:2012.9.21
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 beta-phosphonium enoate alpha-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.