Palladium-catalyzed intermolecular coupling of 2-haloallylic acetates with simple phenols, and sequential formation of benzofuran derivatives through the intramolecular cyclization
synthesis of 2-substituted benzofuran derivatives by the palladium-catalyzed reaction of 2-haloallylic acetates with simple phenols in the presence of a base. The reaction proceeded through the intermolecular attack of the nucleophile on the central carbon atom of the π-allyl group, carbon-halogen bond cleavage, and sequential intramolecularcyclization.
We investigated the intermolecular coupling reaction of 2-fluoroallylic acetates with simple phenols by the [Pd(C3H5)Cl]2, DPPF, and KHMDS at 100 °C for 16 h, and succeeded in obtaining 2-substituted benzofuran derivatives in good to high yield through the C–F bond activation and intermolecular cyclization.
我们研究了[Pd(C 3 H 5)Cl] 2,DPPF和KHMDS在100°C下16 h的2-氟烯丙基乙酸酯与简单酚的分子间偶联反应,并成功获得了2-取代的苯并呋喃衍生物。通过CF键活化和分子间环化,具有良好至高产的效果。
Palladium-catalyzed intermolecular coupling of 3-substituted propargylic carbonates with phenols: Synthesis of 2-substituted benzofuran derivatives
accomplished the synthesis of 2-substituted benzofuran derivatives by the palladium-catalyzed reaction of 3-substituted propargylic carbonates with phenols. The 2-substituted benzofuran derivatives were obtained through the intermolecularcoupling of the 3-substituted propargylic carbonates with phenols, and sequential intramolecular cyclization reaction.
Impregnated Copper(II) Oxide on Magnetite as Catalyst for the Synthesis of Benzo[<i>b</i>
]furans from 2-Hydroxyarylcarbonyl Derivatives and Alkynes
作者:Juana M. Pérez、Diego J. Ramón
DOI:10.1002/ejoc.201600671
日期:2016.9
o-hydroxybenzaldehydes with alkynes in the presence of 4-methylbenzenesulfonohydrazide was carried out in ethanol as a nontoxic biorenewable solvent and in the presence of impregnated copper(II) oxide on magnetite as a heterogeneous catalyst. The catalyst can be easily removed from the reaction medium by a simple magnetic decantation, and the reaction can be performed with a very low copper loading. The in situ
邻羟基苯甲醛与炔烃在 4-甲基苯磺酰肼存在下的偶联-烯丙基化-环化反应序列在乙醇中进行,乙醇作为无毒的生物可再生溶剂,并在磁铁矿上浸渍的氧化铜(II)作为多相催化剂存在。通过简单的磁倾析可以很容易地从反应介质中去除催化剂,并且反应可以在非常低的铜负载下进行。起始的氧化铜 (II) 纳米粒子原位还原成铜 (0) 片材使得催化剂的可回收性变得不可能。该反应的多功能性通过使用不同的邻羟基苯乙酮得到 2,3-二取代的苯并 [b] 呋喃来证明。该反应可以在克规模上进行而没有任何并发症。
CuBr-Catalyzed Coupling of <i>N-</i>Tosylhydrazones and Terminal Alkynes: Synthesis of Benzofurans and Indoles
作者:Lei Zhou、Yi Shi、Qing Xiao、Yizhou Liu、Fei Ye、Yan Zhang、Jianbo Wang
DOI:10.1021/ol103009n
日期:2011.3.4
A new method for the synthesis of benzofurans or indoles via ligand-free CuBr-catalyzed coupling/cyclization of terminalalkynes with N-tosylhydrazones derived from o-hydroxy- or o-aminobenzaldehydes has been developed. A wide range of functional groups were found that are able to tolerate the reaction conditions.