通过极性增强实现远程甲基位的高度选择性C-H键氧化
Sergio Sisti1, Marco Galeotti2, Filippo Scarchilli2
1Dipartimento di Scienze e Tecnologie Chimiche, Università "Tor Vergata", Via della Ricerca Scientifica, 1, I-00133 Rome, Italy.
Journal of the American Chemical Society
|September 26, 2023
概括
这项研究展示了一种使用催化剂和过氧化选择性C(sp3) -H键氧化的新方法. 该反应在各种基质的偏远位置实现了高产量和位点选择性,特别是在键捐赠溶剂中.
科学领域:
- 有机化学
- 催化剂
- 合成方法
背景情况:
- 在有机合成中,选择性功能化C ((sp3) -H键仍然是一个重大挑战.
- 氧化反应对于引入含氧功能组至关重要.
- 在涉及多个类似的C-H键的反应中控制位点选择性是很困难的.
研究的目的:
- 使用 H2O2 和 [Mn(OTf) 2 ((TIPSmcp)) 催化剂来研究环基和1-基基的C(sp3) -H键氧化.
- 评估键捐赠 (HBD) 溶剂对反应产量和位点选择性的影响.
- 开发一个可预测和高度选择性氧化方法,用于偏远的甲基位.
主要方法:
- 用过氧化 (H2O2) 催化氧化带有提取电子的功能组 (EW FG) 的基板.
- 用乙尼 (MeCN) 进行的氧化反应与强型HBD溶剂如1,1,3,3-二醇 (HFIP) 和非三醇 (NFTBA) 的比较.
- 对不同甲基位的氧化产品比率 (PR) 和位点选择性的分析.
主要成果:
- 在各种基质的偏远甲基位获得了高产量和前所未有的位点选择性 (> 99%).
- 在从MeCN转向HBD溶剂 (HFIP,NFTBA) 时,部位选择性显著增加.
- 由EWG和溶剂结带来的"极性增强"效应合理化了观察到的选择性.
结论:
- 已经开发出一种简单,温和和高效的选择性氧化远程C(sp3) -H键的方法.
- 该方法显示了广泛的基质范围,并提供可预测的选择性控制.
- 这种方法为合成有机化学提供了一个强大的新工具.
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