Direct C−H Bond Arylation: Selective Palladium-Catalyzed C2-Arylation of <i>N</i>-Substituted Indoles
作者:Benjamin S. Lane、Dalibor Sames
DOI:10.1021/ol0490072
日期:2004.8.1
We present a new, practical method by which N-substituted indoles may be selectively arylated in the C2-position with good yields, low catalyst loadings, and a high degree of functional group tolerance. Our investigation found that two competitive processes, namely, the desired cross-coupling and biphenyl formation, were operative in this reaction. A simple kinetic model was formulated that proved
Transition‐Metal‐Free Synthesis of Heterobiaryls through 1,2‐Migration of Boronate Complex
作者:Swagata Paul、Kanak Kanti Das、Samir Manna、Santanu Panda
DOI:10.1002/chem.201904761
日期:2020.2.11
carbon atom. Subsequent oxidation of the intermediate boronic ester afforded heterobiaryls in good yield. A comprehensive 11 B NMR study has been conducted to support the mechanism. The cross coupling between two nucleophilic cross coupling partners without transition metals reveals a reliable manifold to procure heterobiaryls in good yields. Various heterocycles like furan, thiophene, benzofuran, benzothiophene
通过使用锂化的杂环,芳基或杂芳基硼酸酯和亲电卤素源,通过无过渡金属的sp2-sp2交叉偶联策略,可以实现多种杂芳基芳基化合物的合成。杂二芳基的构建是通过亲电活化芳基-杂芳基硼酸酯络合物进行的,这引发了1,2-从硼向碳原子的迁移。中间体硼酸酯的随后氧化以良好的产率提供了杂联二芳基。已经进行了全面的11 B NMR研究以支持该机理。在没有过渡金属的情况下,两个亲核交叉偶联伙伴之间的交叉偶联显示了可靠的歧管,可以以高收率获得杂二芳基。呋喃,噻吩,苯并呋喃,苯并噻吩和吲哚等各种杂环具有良好的耐受性。最后,
Fluorous silica gel-supported perfluoro-tagged palladium nanoparticles: an efficient and reusable catalyst for direct C-2 arylation of indoles
作者:Liang Wang、Wen-bin Yi、Chun Cai
DOI:10.1039/c0cc01666g
日期:——
The preparation of FSG-supported palladiumnanoparticles and their application in direct C-2 arylation of indoles are presented. Moderate to good yields were obtained with ultra-low catalyst loading. The catalyst could be easily recovered by simple workup and reused up to seven runs with only a slight decrease in its activity.
Direct C-H Arylation of Heteroarenes with Aryl Chlorides by Using an Abnormal N-Heterocyclic-Carbene-Palladium Catalyst
作者:Jasimuddin Ahmed、Samaresh Chandra Sau、Sreejyothi P、Pradip Kumar Hota、Pavan K. Vardhanapu、Gonela Vijaykumar、Swadhin K. Mandal
DOI:10.1002/ejoc.201601218
日期:2017.2.3
Herein, we report a versatilecatalyticsystem for the direct C–H arylation of heteroarenes with activated arylchloride substrates. The catalyst works successfully for a variety of heteroarenes and arylchloride coupling partners under very low catalyst-loading conditions. We have successfully performed the direct C–H arylations of 1-methylpyrrole, 1-methylindole, furan, thiophene, furfural, and N-benzyl-1
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。