Copper-catalyzed [2+3]-annulation of N–H imines with vinyl azides: access to polyaryl 2<i>H</i>-imidazoles
作者:Zhongzhi Zhu、Hanze Lin、Baihui Liang、Junjie Huang、Wanyi Liang、Lu Chen、Yubing Huang、Xiuwen Chen、Yibiao Li
DOI:10.1039/c9cc10042c
日期:——
A practical method for the synthesis of 2H-imidazoles via a [2+3] annulation of N-H imines with vinylazides using a copper catalyst is developed. In this conversion, environmentally friendly oxygen is used as the sole oxidant and N2 and H2O are the only by-products. The catalytic transformation, operating under mild conditions, is operationally simple and is considered as a readily available catalytic
Selective Oxidative [4+2] Imine/Alkene Annulation with H<sub>2</sub>
Liberation Induced by Photo-Oxidation
作者:Xia Hu、Guoting Zhang、Faxiang Bu、Aiwen Lei
DOI:10.1002/anie.201711359
日期:2018.1.26
The oxidative [4+2] annulationreaction represents an elegant and versatile syntheticprotocol for the construction of six‐membered heterocyclic compounds. Herein, a photoinduced oxidative [4+2] annulation of NH imines and alkenes was developed by utilizing a dual photoredox/cobaloxime catalytic system. Various multisubstituted 3,4‐dihydroisoquinolines can be obtained in good yields. This method is
New greenfluorescentprotein (GFP) chromophoreanalogues, namely 4-(diarylmethylene)imidazolinones (DAINs), were readily synthesized under weakly acidic conditions using a novel condensation reaction between methyl imidate (or thioimidate) and ethyl N-(diarylmethylene)glycinate. DAINs showed notable fluorescence properties. Although they were nearly non-fluorescent in the solution, visible emissions
intermediates for synthesizing valuable nitrogen-containing compounds, but their potential applicability is limited by the available synthetic methods. To address this issue, we report a scandium(III) triflate catalyzed direct synthesis of N-unprotected ketimines. Using commercially available reagents and Lewis acid catalysts, ketones were directly transformed into the corresponding N-unprotected ketimines
Ruthenium(II)/N-Heterocyclic Carbene Catalyzed [3+2] Carbocyclization with Aromatic NH Ketimines and Internal Alkynes
作者:Jing Zhang、Angel Ugrinov、Pinjing Zhao
DOI:10.1002/anie.201209031
日期:2013.6.24
which occurs at ambient temperature, in the absence of oxidants or other metal salts, and in nonpolar solvents. A proposed mechanism involves imine‐directed activation of an aromatic CH bond, alkyne insertion, and carbocyclization by intramolecular imine insertion into Ru–alkenyl linkages.
方便且高效:使用标题反应合成茚胺,该反应在环境温度、不存在氧化剂或其他金属盐的情况下以及在非极性溶剂中发生。提出的机制涉及芳族 C - H 键的亚胺定向活化、炔烃插入以及通过分子内亚胺插入 Ru-烯基键进行碳环化。