在有氧条件下从空气中引入氧原子在有机合成中起着重要作用。在此,布朗斯台德酸被发现是一种二合一的战略催化剂,在可见光条件下无需外部光催化剂即可将烯胺从β-氧代酰胺和胺转化为吡咯啉-4-酮。布朗斯台德酸可以抑制烯胺和1 O 2生成的[2 + 2]加合物的 C-C 键断裂,但最重要的是,它可以通过酸变色作用与烯胺和吡咯啉-4-酮产物形成光敏剂,促进1 O 2代。
In Situ Generated TEMPO Oxoammonium Salt Mediated Tandem Cyclization of β-Oxoamides with Amine Hydrochlorides for the Synthesis of Pyrrolin-4-ones
作者:Xuna Zhao、Tong-Xin Liu、Nana Ma、Guisheng Zhang
DOI:10.1021/acs.joc.7b00686
日期:2017.6.16
A novel in situ generated TEMPO oxoammonium salt mediated one-pot tandem reaction has been developed for the straightforward construction of pyrrolin-4-ones from readily available β-oxoamides with amine hydrochlorides. The reaction tolerates various functional groups and represents a reliable method for the synthesis of highly substituted pyrrolin-4-ones in good yields under mild conditions. Detailed
oxidative dimerization of enamines to produce pyrrolin-4-ones in good to excellent yields. Mechanistic studies reveal the formation of the imino ketone intermediate from the interaction of 1O2 and enamine, which is able to interact with Lewis acid, relaying the 1O2 reaction in enamine chemistry. For the first time, selective cross-dimerization of two different enamines is achieved. Due to the advantages
单线态氧 ( 1 O 2 ) 介导的氧化代表了一种有吸引力的策略,可以在温和和环境友好的条件下结合空气中的氧原子。然而,与烯胺的1 O 2反应会发生碎片化,导致转化非常不成功。在这里,路易斯酸被引入以拦截1 O 2反应的 [2 + 2] 或“烯”反应中间体,并使烯胺的氧化二聚化以良好至优异的产率产生 pyrrolin-4-one。机理研究揭示了亚氨基酮中间体的形成来自1 O 2的相互作用和烯胺,它能够与路易斯酸相互作用,在烯胺化学中传递1 O 2反应。首次实现了两种不同烯胺的选择性交叉二聚化。由于条件温和、化学选择性高、收率高达 99% 等优点,已开发出一种在环境条件下合成氮杂杂环化合物的有前景的策略,可进一步用于咪唑酮、喹喔啉和高度官能化亚胺的合成.
10.1021/acs.joc.4c00833
作者:Oyejobi, Aanuoluwapo O.、Huang, Jie、Luo, Yun-Xuan、Tang, Xiang-Ying、Wang, Long
DOI:10.1021/acs.joc.4c00833
日期:——
The incorporation of oxygen atoms from air under aerobic conditions plays an important role in organic synthesis. Herein, Brønsted acids are found to be a two-in-one strategic catalyst to transform enamines from β-oxoamides and amines to pyrrolin-4-ones without an external photocatalyst under visible-light conditions. The Brønsted acid can inhibit the C–C bond fragmentation of the [2 + 2] adduct from
在有氧条件下从空气中引入氧原子在有机合成中起着重要作用。在此,布朗斯台德酸被发现是一种二合一的战略催化剂,在可见光条件下无需外部光催化剂即可将烯胺从β-氧代酰胺和胺转化为吡咯啉-4-酮。布朗斯台德酸可以抑制烯胺和1 O 2生成的[2 + 2]加合物的 C-C 键断裂,但最重要的是,它可以通过酸变色作用与烯胺和吡咯啉-4-酮产物形成光敏剂,促进1 O 2代。
Cu(TFA)<sub>2</sub>-Catalyzed Oxidative Tandem Cyclization/1,2-Alkyl Migration of Enamino Amides for Synthesis of Pyrrolin-4-ones
A novel Cu(TFA)(2)-catalyzed oxidative tandem cyclization/1,2-alkyl migration of readily available enamino amides for the synthesis of pyrrolin-4-ones has been developed. The reaction tolerates a wide range of functional groups and is a reliable method for the rapid synthesis of substituted pyrrolin-4-ones in high yields under mild conditions.
Tandem annulation and 1,2-alkyl migration reactions of α-bromo-β-oxoamides and amines: Access to polysubstituted pyrrolin-4-ones