使用硫作为碳等效的孤儿环的有效合成
John Douglas Johnson1, Charles Reece Teeples1, Nicholas Rajai Akkawi1
1Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States.
Journal of the American Chemical Society
|August 8, 2022
概括
这项研究引入了一种使用硫离子合成1,1-二环的新方法. 这种方法克服了金属催化碳转移的局限性,使得有效的环生成成为可能.
科学领域:
- 有机化学
- 合成化学
- 催化剂
背景情况:
- 1,1-二甲基cyclopropanes 在许多天然产品中发现重要的结构图案.
- 现有的合成方法,如金属催化碳转移,经常受到1,2-转移等竞争性副作用的影响,从而限制了它们的效率和范围.
研究的目的:
- 开发一种用于合成1,1-二环的新且机械上不同的方法.
- 提供一种替代现有方法,避免有问题的副作用.
主要方法:
- 使用基硫离子与烯的碳金属化反应.
- 使用胺 (NaNH2) 或n-丁 (n-BuLi) 作为以太溶剂中的基.
- 在23°C至70°C的温度下与烯和烯反应.
主要成果:
- 成功合成了各种具有高分离产量的1,1-二甲基cyclopropanes (高达89%).
- 证明了该方法的多功能性,使用了16种不同的 styrenes,9种不同的 arylbutadienes 和13种不同的 sulfones.
- 报告了一种序列循环化反应的例子,展示了该方法对复杂合成的潜力.
- 预先的机械研究表明,通过添加硫离子启动一个阶段性的离子过程.
结论:
- 开发的方法为合成1,1-二甲基cyclopropanes提供了一个高效和多功能平台.
- 这种碳化方法为现有的合成策略提供了有价值的替代方案,克服了与金属催化碳转移相关的局限性.
- 反应通过不同的离子通路进行,扩大了环合成的工具包.
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