• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chemistry: A European journal >Functionalization and Rearrangement of Spirocyclohexadienyl Oxindoles: Experimental and Theoretical Investigations
【24h】

Functionalization and Rearrangement of Spirocyclohexadienyl Oxindoles: Experimental and Theoretical Investigations

机译：螺环己二烯氧基吲哚的功能化和重排：实验和理论研究

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 preparation and functionalization of spirocyclohexa-2,5- diene oxindoles is described. The spirocyclic core of the title compounds was installed by using a SmI2-mediated cyclization of aryl iodobenzamides. Epoxidation with CF3CO3H was then carried out and was shown to occur with a high level of diastereocontrol: the reagent approaches the diene moiety syn to the amide group, which is likely to be as a consequence of hydrogen bonding between the amide C=O bond and the peracid hydrogen. Carbanionic functionalization of the spirocyclohexa- 2,5-diene oxindoles was then examined, leading to an unprecedented rearrangement of the strained spiro system into dearomatized phenanthridinones. Upon treatment with lithium diisopropylamide (LDA) at 40 8C, the dienes rearranged to provide a phenanthridinone lithium enolate intermediate that was trapped by electrophiles including alkyl halides and aldehydes. Interestingly, alkylation and hydroxyalkylation occurred with different regiocontrol. DFT calculations were performed that rationalize the observed skeleton rearrangement, emphasizing the role of LDA/diisopropylamine in this rearrangement. The proposed mechanism thus relies on a thermodynamically driven diisopropylamine-mediated proton transfer with the cleavage of the diene–amide C=O bond as the key step.
机译：描述了螺环己-2,5-二烯恶吲哚的制备和功能化。通过使用SmI2介导的芳基碘苯甲酰胺环化来安装标题化合物的螺环核心。然后进行CF3CO3H环氧化，并显示出高水平的非对映异构控制：该试剂接近酰胺基的二烯部分，这很可能是由于酰胺C = O键和过酸氢。然后检查了螺环六—2，5-二烯恶吲哚的碳负离子官能化，导致应变螺旋系统前所未有地重排为脱芳香族化的菲啶酮。在40±8℃下用二异丙基酰胺锂（LDA）处理后，二烯重排以提供一种菲啶酮锂烯醇盐中间体，该中间体被包括烷基卤和醛的亲电试剂捕获。有趣的是，烷基化和羟烷基化在不同的区域控制下发生。进行DFT计算以合理化观察到的骨架重排，强调LDA /二异丙胺在这种重排中的作用。因此，所提出的机理依赖于热力学驱动的二异丙基胺介导的质子转移，其中二烯酰胺C = O键的裂解是关键步骤。

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