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
Rh(III)-Catalyzed C–C/C–N Coupling of Imidates with α-Diazo Imidamide: Synthesis of Isoquinoline-Fused Indoles
作者:He Wang、Lei Li、Songjie Yu、Yunyun Li、Xingwei Li
DOI:10.1021/acs.orglett.6b01284
日期:2016.6.17
Imidate esters and diazo compounds have been established as bifunctional substrates for the construction of biologically active fused heterocycles viarhodium-catalyzed C–H activation and C–C/C–N coupling. This reaction occurs undermildconditions with high efficiency, step economy, and low catalyst loading.
activator for carboxylic acids is the key to bypass a competing single‐electron‐transfer mechanism and “switch on” an energy‐transfer‐mediated homolysis of unsymmetrical σ‐bonds for a concertedfragmentation/decarboxylation process.
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