• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chemistry: A European journal >Cr/Ni-catalyzed vinylation of aldehydes: A mechanistic study on the catalytic roles of nickel and chromium
【24h】

Cr/Ni-catalyzed vinylation of aldehydes: A mechanistic study on the catalytic roles of nickel and chromium

机译：Cr / Ni催化醛的乙烯基化：镍和铬催化作用的机理研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The roles of nickel and chromium catalysts in the coupling reaction of vinyl halides and aldehydes, the so-called Nozaki-Hiyama-Kishi (NHK) reaction, have been studied by UV/Vis spectroscopy, electrochemical, and spectroelectrochemical methods. Electrochemical studies revealed that nickel plays the central role in activating the vinyl halide by reductive cleavage, to form a rapidly decomposing vinyl-Ni species. The latter can, however, be stabilized in the presence of the Cr complex. The redox behavior of the Ni complexes in the presence of vinyl halide demonstrated that the vinyl halide activation results from interaction with a one-electron reduced nickel species [formally NiI], not necessarily with a Ni0 species. It was furthermore shown by UV/Vis spectroscopy and spectroelectrochemical methods that low-valent nickel [Ni0] results from the interaction of the NiII catalyst with CrCl_2. It takes two to tango! The initial stages of the Cr/Ni-catalyzed vinylation of aldehydes (the Nozaki-Hiyama-Kishi reaction) were analyzed by electrochemical methods. The role of low-valent nickel in the C-halogen(Hal) cleavage of the vinyl halide was established, as well as the generation of the former from Ni~(II) and Cr~(II).
机译：镍和铬催化剂在乙烯基卤化物和醛的偶联反应中的作用，即所谓的Nozaki-Hiyama-Kishi（NHK）反应，已通过UV / Vis光谱，电化学和光谱电化学方法进行了研究。电化学研究表明，镍在通过还原裂解活化卤乙烯以形成快速分解的乙烯基镍物种中起着核心作用。然而，后者可以在Cr络合物的存在下稳定。 Ni络合物在卤化乙烯存在下的氧化还原行为表明，卤化乙烯的活化是由于与单电子还原的镍物种（形式为NiI）相互作用，而不一定与Ni0物种相互作用。此外，通过UV / Vis光谱和光谱电化学方法表明，低价镍[Ni0]是NiII催化剂与CrCl_2的相互作用产生的。一个巴掌拍不响！通过电化学方法分析了Cr / Ni催化的醛的乙烯基化的初始阶段（野崎-Hiyama-Kishi反应）。建立了低价镍在卤乙烯的C-卤素（Hal）裂解中的作用，以及前者由Ni〜（II）和Cr〜（II）的生成。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号