Double C-H Functionalization to Construct Polycyclic Heteroarenes Catalyzed by an Ionic Salt of a Pd Complex with an N-Heterocyclic Carbene Ligand
作者:Sanjay Kumar Ghosh、Bing-Chiuan Kuo、Hsiang-Yu Chen、Jia-Ying Li、Shuang-De Liu、Hon Man Lee
DOI:10.1002/ejoc.201500417
日期:2015.7
A new ionicsalt, cis-[Pd(L)(PPh3)(H2O)2](SO3CF3)2 (A), in which L is an amido-functionalized N-heterocycliccarbene (NHC) ligand, has been prepared by the salt metathesis reaction between [Pd(L)(PPh3)Cl2] and AgOTf in wet acetonitrile. It was successfully characterized by NMR spectroscopy, elemental analysis, and single-crystal X-ray diffraction analysis. Complex A was found to be effective in catalyzing
一种新的离子盐,顺式-[Pd(L)(PPh3)(H2O)2](SO3CF3)2 (A),其中 L 是酰胺基官能化的 N-杂环卡宾 (NHC) 配体,由[Pd(L)(PPh3)Cl2] 和 AgOTf 在湿乙腈中的盐复分解反应。通过核磁共振谱、元素分析和单晶X射线衍射分析成功地对其进行了表征。发现配合物 A 在 Cu(OAc)2 和四正丁基溴化铵的存在下,可有效催化各种含氮和硫杂芳烃的双 C-H 官能化,以与炔烃形成稠合的多环杂芳烃化合物。吲哚、噻吩、咪唑并[1,2-a] 吡啶和咪唑用作底物。特别是,在所采用的条件下,可以获得有趣的咪唑并[5,1,2-cd]吲哚嗪化合物。
A Palladium-Catalyzed Oxidative Cycloaromatization of Biaryls with Alkynes Using Molecular Oxygen as the Oxidant
Dual activation of CH bonds has enabled the preparation of polycyclic aromatics from arylindoles and arylbenzofurans in the absence of a directing group, and with using O2 as the oxidant (see scheme). Synthetically and medicinally important polycyclic aromatics have been easily prepared, and some of the resulting polycyclic heteroaromatics exhibit intense fluorescence.
A palladium-catalyzed tandem cyclization/C-H functionalization of two alkynes was accomplished to construct a series of polycyclic functionalized indoles. A range of internal alkynes bearing synthetically useful functional groups were tolerated. A good regioselectivity was observed when alkyl-substituted alkynes were introduced into the reaction system, and a single product was obtained. Molecular oxygen was used as the terminal oxidant in the approach, rendering the reaction more sustainable.
10.1021/acs.joc.4c00746
作者:Zhang, Lijun、Wang, Zhuo、Song, Zhiguang
DOI:10.1021/acs.joc.4c00746
日期:——
benzo[a]carbazole and dibenzo[c,g]carbazole frameworks. The detailed gold catalytic reaction conditions developed for the challenging intermolecular carbon nucleophilic addition to internal alkynes are realized, giving the desired alkyne hydroarylation products in good yields. The resulting trisubstituted alkenes are able to undergo photomediated cyclization, furnishing the desired carbazole molecules
在此,我们报告了构建苯并[ a ]咔唑和二苯并[ c , g ]咔唑框架的反应方案。实现了为内部炔烃进行具有挑战性的分子间碳亲核加成而开发的详细金催化反应条件,以良好的收率得到了所需的炔烃加氢芳基化产物。所得三取代烯烃能够进行光介导环化,以优异的产率和高效率提供所需的咔唑分子。