亲核芳香取代 (S N Ar) 是一种通过用亲核试剂取代离去基团将杂原子结合到芳香环中的强大策略,但这种方法仅限于缺电子芳烃。我们现在已经建立了一种通过催化 S N Ar 反应获取苯酚和苯基烷基醚的可靠方法。该方法适用于广泛的富电子和中性芳基氟化物,它们在经典的 S N Ar 条件下呈惰性。虽然 S N的机制假设涉及金属芳烃配合物的 Ar 反应涉及逐步途径(添加后消除),支持该假设的实验数据仍在探索中。机械研究和 DFT 计算表明了一个逐步或逐步的能量分布。值得注意的是,我们分离了铑 η 5 -环己二烯基复合中间体,其具有带有亲核试剂和离去基团的 sp 3 -杂化碳。
Palladium-Catalyzed Intra- and Intermolecular C–H Arylation Using Mesylates: Synthetic Scope and Mechanistic Studies
作者:Devin M. Ferguson、Stacey R. Rudolph、Dipannita Kalyani
DOI:10.1021/cs500587b
日期:2014.7.3
This paper describes the development of Pd-catalyzed inter- and intramolecular direct arylation using mesylates. Furthermore, a sequential mesylation/arylation protocol using phenols as substrates is described. These transformations are general with respect to the electronics of the C-H substrates and allow for the synthesis of diverse heterocyclic motifs in good yields. Both arenes and heteroarenes
Palladium-Catalyzed Intramolecular C–H Arylation of Arenes Using Tosylates and Mesylates as Electrophiles
作者:Christine S. Nervig、Peter J. Waller、Dipannita Kalyani
DOI:10.1021/ol302166n
日期:2012.9.21
paper describes a method for the palladium catalyzed intramolecular C–H arylation using tosylates and mesylates as electrophiles. The transformation is efficient for the synthesis of various heterocyclic motifs including furans, carbazoles, indoles, and lactams. Additionally, a protocol for the one-pot sequential tosylation/arylation of phenol derivatives is presented.
Quinoline Ligands Improve the Classic Direct C−H Functionalisation/Intramolecular Cyclisation of Diaryl Ethers to Dibenzofurans
作者:Katrina Mackey、David J. Jones、Leticia M. Pardo、Gerard P. McGlacken
DOI:10.1002/ejoc.202001416
日期:2021.1.22
Intramolecular arylation through direct C−H functionalisation is a convenient method for the formation of dibenzofurans. In the Pd‐mediated process, the use of quinoline ligands alleviates a number of the existing issues with the use of phosphineligands.
dibenzoxaborins to dibenzofurans by deborylative ring contraction was achieved under mild conditions using a copper catalyst. The method showed a broad substrate scope enabling the preparation of various dibenzofurans, including those bearing a functional group. The ready availability of various dibenzoxaborins enhances the utility of this method, as demonstrated by the regiodivergent synthesis of dibenzofurans
Photoinduced Synthesis of Dibenzofurans: Intramolecular and Intermolecular Comparative Methodologies
作者:Patricia Camargo Solórzano、Federico Brigante、Adriana B. Pierini、Liliana B. Jimenez
DOI:10.1021/acs.joc.8b00742
日期:2018.8.3
The SRN1 reaction has been used as a powerful tool for the synthesis of heterocycles, and only a few studies about photoinduced intramolecular cyclization to generate a new C–O bond by a radical pathway have been reported. This work introduces two strategies for the synthesis of substituted dibenzofurans by electron transfer (eT) reactions. The first one is a three-step process that comprises bromination
S RN 1反应已被用作合成杂环的有力工具,并且仅报道了少数有关通过自由基途径光诱导分子内环化以生成新的C-O键的研究。这项工作介绍了两种通过电子转移(eT)反应合成取代的二苯并呋喃的策略。第一个是三步过程,其中包括溴化o-芳基苯酚,Suzuki-Miyaura交叉偶联和光诱导的环化反应,以获得上述产物。第二种是无金属工艺,不需要任何光催化剂。测试了不同的溶剂,收率范围从低到中等。在两种方法之间建立了比较,表明第二种方法最适合合成二苯并呋喃。