An Aryl to Imidoyl Palladium Migration Process Involving Intramolecular C−H Activation
作者:Jian Zhao、Dawei Yue、Marino A. Campo、Richard C. Larock
DOI:10.1021/ja070657l
日期:2007.4.1
imidoyl palladium migration, followed by intramolecular arylation. The fluoren-9-one synthesis appears to involve both a palladium migration mechanism and a C-H activation process proceeding through an unprecedented organopalladium(IV) hydride intermediate. The results from deuterium labeling experiments are consistent with the proposed dual mechanism.
CBr<sub>4</sub> promoted intramolecular aerobic oxidative dehydrogenative arylation of aldehydes: application in the synthesis of xanthones and fluorenones
作者:Jing Tang、Shijun Zhao、Yuanyuan Wei、Zhengjun Quan、Congde Huo
DOI:10.1039/c7ob00080d
日期:——
promoted intramolecular aerobic oxidative dehydrogenative coupling reaction has been developed to provide a straightforward ring closure protocol for 2-aryloxybenzaldehydes to furnish xanthones. The reaction was performed under metal-, additive- and solvent-free conditions with good tolerance of functional groups. The present method is also applicable to the synthesis of fluorenones by using 2-arylbenzaldehydes
A HOAc‐catalyzed aryloxy/alkoxy‐assisted nucleophilic addition of 2‐methylquinolines to aldehydes in water has been described. The reaction provides an efficient and direct access to hydroxyquinolines in moderate to good yields. In addition, a HOAc/1,3‐DMBBA (1,3‐dimethylbarbituric acid) synergistic organocatalysis system were also developed for the synthesis of alkenylquinolines.
Acid-catalysed intramolecular Friedel–Crafts annulation of hetero-atom-functionalized <i>para</i>-quinone methides: access to O-, S- and N-based heterocycles
We describe here an acid-mediated one-pot approach to access substituted xanthene and thioxanthane derivatives from ortho-heteroaryl phenyl-substituted para-quinone methides via 1,6 intramolecular arylation. The scope of this work was further elaborated to the synthesis of 10H-indolo[1,2-a]indole-based heterocyclic systems using indole based para-quinone methides.
我们在这里描述了一种酸介导的一锅法,通过1,6 分子内芳基化从邻杂芳基苯基取代的对醌甲基化物中获得取代的呫吨和噻吨烷衍生物。这项工作的范围进一步阐述为使用吲哚基对醌甲基化物合成10 H-吲哚并[1,2- a ]吲哚基杂环系统。
Metal-Free Oxidative Coupling: Xanthone Formation<i>via</i>Direct Annulation of 2-Aryloxybenzaldehyde using Tetrabutylammonium Bromide as a Promoter in Aqueous Medium
作者:Honghua Rao、Xinyi Ma、Qianzi Liu、Zhongfeng Li、Shengli Cao、Chao-Jun Li
DOI:10.1002/adsc.201300488
日期:2013.8.12
AbstractA metal‐free intramolecular annulation of 2‐aryloxybenzaldehydes to xanthones is disclosed, which proceeds through the direct oxidative coupling of an aldehyde CH bond and aromatic CH bonds using tetrabutylammonium bromide (TBAB) as a promoter in aqueous medium. This strategy works smoothly in the presence of both electron‐donating and electron‐withdrawing groups, and displays good tolerance towards catalytically reactive substituents, thus promising further functionalizations of xanthone products.magnified image