本文我们报告一个新的和更实际的方法来制备宝石从末端炔烃,四溴甲烷(CBR -dibromoenones 4在单个步骤中),和水。机理研究表明,在过硫酸盐(K 2 S 2 O 8)的帮助下生成三溴甲基自由基对于这种转化是必不可少的。该反应具有易得的化学品、广泛的底物范围、绿色溶剂和温和的反应条件,为构建卤素取代的烯酮提供了有效的替代方案。
Functionalized β,β-dichloroenones and β,β-dibromoenones as versatile building blocks: Synthesis and transformations
作者:Dengke Li
DOI:10.1016/j.tetlet.2021.153551
日期:2021.12
functionalized β,β-dichloroenones and β,β-dibromoenones was achieved via the Fe-catalyzed radical induced reactionbetween silyl enol ethers and carbontetrachloride, bromotrichloromethane or carbon tetrabromide in moderate to good yields. This reaction proceeds through addition of the trichloromethyl or tribromomethyl radical group to the CC bond of the silyl enol ethers and subsequent base-induced elimination
通过甲硅烷基烯醇醚与四氯化碳、溴三氯甲烷或四溴化碳之间的 Fe 催化自由基诱导反应,以中等至良好的收率实现了功能化β,β-二氯烯酮和β,β-二溴烯酮的高效一步合成。该反应通过将三氯甲基或三溴甲基自由基添加到甲硅烷基烯醇醚的 C C 键上并随后在温和条件下进行碱诱导消除来进行。
Silyl alkenyl ethers as the synthetic equivalent of enols. A new synthesis of αβ-unsaturated ketones
consecutive tandem processes are described for the regioselective, two-step synthesis of 1,3,5-trisubstitutedpyrazoles from α-hydroxyketones. The first, a tandem MnO 2 -mediated oxidation/Ramirez olefination reaction, provides a facile route to β,β-dibromo-enones. These valuable 1,3-dicarbonyl synthons can then be converted into 1,3,5-trisubstitutedpyrazoles via a second tandem hydrazine condensation/Suzuki-Miyaura
Synthesis of 2,2-di(pyrazol-1-yl)enones via the 2:1 coupling of pyrazoles and acylbromoacetylenes in solid alumina
作者:Maxim D. Gotsko、Lyubov' N. Sobenina、Alexander V. Vashchenko、Boris A. Trofimov
DOI:10.1016/j.tetlet.2018.10.033
日期:2018.11
intermediates, (Z)-2-bromo-2-(pyrazol-1-yl)enones. This unexpected 2:1 coupling is in contrast to similar reactions of pyrroles, furans and thiophenes, which give the corresponding acylethynyl derivatives. This reaction opens a one-pot route to inaccessible gem-dipyrazolylenones, which have potential applications as bidentate chelating ligands and building blocks for drug design.
吡唑在室温下与固体Al 2 O 3中的酰基溴乙炔反应,以22-69%的产率提供2,2-二(吡唑-1-基)烯酮。反应通过可分离的中间体(Z) -2-溴-2-(吡唑-1-基)烯酮进行。这种出乎意料的2:1偶联与吡咯,呋喃和噻吩的类似反应形成了相应的酰基乙炔基衍生物。该反应为难于获得的宝石-二吡唑基亚酮打开了一条锅路,这些潜在的应用有可能用作双齿螯合配体和药物设计的基础。
Synthesis of 3-[5-(biphenyl-4-yl)pyrrol-2-yl]-1-phenylprop-2-yn-1-ones by palladium-free cross-coupling between pyrroles and haloalkynes on aluminum oxide
作者:L. N. Sobenina、Z. V. Stepanova、O. V. Petrova、J. Sh. Ma、G. Yang、A. A. Tatarinova、A. I. Mikhaleva、B. A. Trofimov
DOI:10.1007/s11172-013-0011-7
日期:2013.1
Cross-coupling of 2-(biphenyl-4-yl)pyrrolesderivedfrom 1-(biphenyl-4-yl)ethanone oximes and acetylene with 3-bromo-1-phenylprop-2-yn-1-one on aluminum oxide gave 3-[5-(biphe-nyl-4-yl)pyrrol-2-yl]-1-phenylprop-2-yn-1-ones in 35–46% yields.