A simple and practical method to access N-substituted 2-pyridones via a formal [3+3] annulation of enaminones with acrylates based on RhIII-catalyzed C–H functionalization was developed. Control and deuterated experiments led to a plausible mechanism involving C–H bond cross-coupling and aminolysis cyclization. This strategy provides a short synthesis of structural motifs of N-substituted 2-pyridones
Trinuclear Diamagnetic Nickel(II) Complexes with Bridging 3‐Arylpyrazolato Ligands
作者:Kifah S. M. Salih、Susann Bergner、Harald Kelm、Yu Sun、Anneken Grün、Yvonne Schmitt、Roland Schoch、Mark Busch、Naina Deibel、Stefan Bräse、Biprajit Sarkar、Matthias Bauer、Markus Gerhards、Werner R. Thiel
DOI:10.1002/ejic.201300925
日期:2013.12.2
Orange-red trinuclearnickel(II) complexes are obtained by reacting Ni(ClO4)2(H2O)6 with 3(5)-arylpyrazoles in the presence of a base. Herein, the diamagnetic nickel centers are coordinated in a square-pyramidal manner by four pyrazolato ligands, each of which bridges two nickel sites. The structurally unique complexes were investigated by NMR, IR, fluorescence, and X-ray spectroscopy. All seven compounds
在碱存在下,通过 Ni(ClO4)2(H2O)6 与 3(5)-芳基吡唑反应获得橙红色三核镍 (II) 配合物。在此,抗磁性镍中心通过四个吡唑根基配体以方形锥体方式配位,每个配体桥接两个镍位点。通过 NMR、IR、荧光和 X 射线光谱研究了结构独特的配合物。这里描述的所有七种化合物都通过单晶 X 射线衍射在结构上阐明。以 3(5)-二茂铁基吡唑为底物,获得了具有六个氧化还原活性二茂铁基部分的非金属体系。
Reactions of Enaminones with
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‐Quinone Methides: Access to 4H‐Chromene and 4H‐Chromen‐4‐one Derivatives
A common platform to access a privileged class of oxygen-containing heterocycles such as 4H-chromenes and 4H-chromen-4-ones through a Brønsted acid-mediated one-pot reaction between enaminones and p-quinone methides (p-QMs) has been developed. By suitably modifying the p-QMs and/or enaminones, one can selectively access either 4H-chromenes or 4H-chromen-4-ones in moderate to excellent yields under
Facile access to the 2,2-difluoro-2,3-dihydrofuran skeleton without extra additives: DMF-promoted difluorocarbene formation of ClCF<sub>2</sub>CO<sub>2</sub>Na
A practical and facile difluorocarbene-triggered cycloaddition reaction of enaminones was developed, which delivered 2,2-difluoro-2,3-dihydrofurans without any extra additives.
Herein, a B2pin2-mediated radical cascade cyclization/aromatization reaction of enaminone with pyridine is described. This strategy provides a practical way for the construction of valuable functionalized indolizines under metal-, external oxidant-, and base-free conditions, which could be compatible with various kinds of functional groups, such as halogen, π-system, heterocycle, ferrocenyl, etc. A
在此,描述了烯胺酮与吡啶的 B 2 pin 2介导的自由基级联环化/芳构化反应。该策略为在无金属、无外部氧化剂和无碱条件下构建有价值的功能化中氮化合物提供了一种实用的方法,它可以与各种功能基团相容,如卤素、π-系统、杂环、二茂铁基、 etc. 初步的机理研究表明,原位形成的吡啶-硼基自由基引发了反应的发生。