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.
The construction of substituted indole skeletons is always an important concern of synthetic chemists because of its prevalent structure found in natural products and biological molecules. Here, we succeeded in preparing indoles and their derivativesfrom a wide variety of simple enamines viaradical cyclization only with catalytic amounts of an iridium(III) photosensitizer (PS) in DMSO solution under
Iodide-Ion-Catalyzed Carbon-Carbon Bond-Forming Cross-Dehydrogenative Coupling for the Synthesis of Indole Derivatives
作者:Zhenhua Jia、Takashi Nagano、Xingshu Li、Albert S. C. Chan
DOI:10.1002/ejoc.201201585
日期:2013.2
nBu4NI-catalyzed intramolecular cross-dehydrogenativecoupling (CDC) reaction has been applied to the synthesis of 1H-indole derivatives. Intramolecular oxidative coupling of N-arylenamines proceeded in the presence of a catalytic amount of nBu4NI and tert-butyl hydroperoxide (TBHP) to afford the corresponding 1H-indole derivatives in good-to-excellent yields. A preliminary study of the synthesis of 3H-indole is also
Cobalt-catalyzed hydrogenation of β-enamino esters using an internal mixture of bidentate and monodentate ligands
作者:Manuel Amézquita-Valencia、Armando Cabrera
DOI:10.1016/j.jorganchem.2014.06.028
日期:2014.10
Different beta-amino esters have been obtained in good yields by means of octacarbonyldicobalt-catalyzed hydrogenation of beta-enamine esters in the presence of mixture of a bidentate phosphine chiral (R-BINAP) and a monodentate phosphine achiral (PPh3). Likewise, a non-symmetric Co/BINAP/PPh3 complex was isolated. This new compound was used in the hydrogenation reaction under different conditions and the results suggest that this heterocombination could be responsible for improving enantiomeric excess in the reduction products. (C) 2014 Elsevier B.V. All rights reserved.