• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chemistry: A European journal >Homoleptic zincate-promoted room-temperature halogen-metal exchange of bromopyridines
【24h】

Homoleptic zincate-promoted room-temperature halogen-metal exchange of bromopyridines

机译：均一锌酸盐促进的溴吡啶的室温卤素金属交换

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

Homoleptic lithium tri- and tetraalkyl zincates were reacted with a set of bromopyridines. Efficient and chemoselective bromine-metal exchanges were realized at room temperature with a substoichiometric amount of nBu _4ZnLi_2·TMEDA reagent (1/3 equiv; TMEDA=N,N,N′,N′-tetramethylethylenediamine). This reactivity contrasted with that of tBu_4ZnLi_2·TMEDA, which was inefficient below one equivalent. DFT calculations allowed us to rationalize the formation of N?Li stabilized polypyridyl zincates in the reaction. The one-pot difunctionalization of dibromopyridines was also realized using the reagent stoichiometrically. The direct creation of C-Zn bonds in bromopyridines enabled us to perform efficient Negishi-type cross-couplings. Mild zincation! nBu_4ZnLi_2·TMEDA (in substoichiometric amounts) promoted efficient and chemoselective room-temperature bromine-metal exchange of a range of bromopyridines (see scheme). DFT calculations strongly supported the formation of a stabilized tripyridylzincate, which could be reacted with electrophiles or be directly involved in palladium-catalyzed cross-coupling reactions.
机译：使均合的三和四烷基锌酸锂与一组溴吡啶反应。在室温下使用亚化学计量的nBu _4ZnLi_2·TMEDA试剂（1/3当量; TMEDA = N，N，N'，N'-四甲基乙二胺）实现了高效的化学选择的溴金属交换。该反应性与tBu_4ZnLi_2·TMEDA的反应性相反，tBu_4ZnLi_2·TMEDA的效率低于1当量。 DFT计算使我们能够合理化反应中N？Li稳定的聚吡啶基锌酸盐的形成。还使用化学计量的试剂实现了二溴吡啶的一锅双功能化。在溴吡啶中直接创建C-Zn键使我们能够进行有效的Negishi型交叉偶联。轻度镀锌！ nBu_4ZnLi_2·TMEDA（亚化学计量）促进了一系列溴吡啶的高效和化学选择性的室温溴-金属交换（参见方案）。 DFT计算强有力地支持了稳定的三吡啶基锌酸盐的形成，它可以与亲电试剂反应或直接参与钯催化的交叉偶联反应。

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