复杂诱导的近距离效应:不同导向组定向对碳酸导向化反应的影响
1Contribution from the Department of Chemistry, Roger Adams Laboratory, University of Illinois at Urbana-Champaign, 61801, USA.
Journal of the American Chemical Society
|July 18, 2001
概括
这项研究研究了双循环碳酸盐对α-化反应的研究. 形状受限的碳酸盐促进了高效的化,特定的几何因素有利于该过程.
科学领域:
- 有机化学 有机化学
- 立体选择性合成 立体选择性合成
背景情况:
- 碳酸盐是有机合成中的多功能功能组.
- 阿尔法-化是功能化碳酸盐的关键反应.
- 了解碳酸盐导向化过程中的立体化学结果至关重要.
研究的目的:
- 为了研究结构和几何因素对碳酸盐导向的α-化的影响.
- 为了确定双循环碳酸盐的化-替代反应中的立体化学偏好.
- 为了比较形状受限的碳酸盐和Boc胺之间的化效率.
主要方法:
- 选择的双循环碳酸盐的合成和研究.
- 立体选择性化替代反应.
- 竞争实验,以评估化效率.
- 半经验计算以建模过渡状态.
- -交换实验,以评估配置稳定性.
主要成果:
- 通过立体选择性化-替代,佐利丁7-10产生了主要的cis-diastereomers (cis-18-27和cis-31-35).
- 与Boc胺 (4-6) 相比,对形状受限的碳酸盐 (7,10,11,15) 的化效率更高.
- 碳氧与目标质子之间的小二面角和~2.78 Å的C-H距离有利于碳酸导向的化.
- 限制性几何学增强了碳酸盐稳定器官物种的配置稳定性.
结论:
- 结构和几何参数显著影响碳酸导向α-化效率和立体选择性.
- 循环碳酸为受控立体选择性功能化提供了一个平台.
- 这些发现为设计涉及有机中间体的合成策略提供了宝贵的见解.
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