D4-对称的二四 ((二甲基) 催化剂用于未激活的C-H键的反选择性功能化
Ziyi Chen1, Kristin Shimabukuro1, John Bacsa1
1Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States.
新的二催化剂可实现高度选择性的C-H功能化. 修改后的二甲基酸连接物达到最佳的D4对称性,在低催化剂负载的选择性反应中表现优于以前的催化剂.
科学领域:
- 有机金属化学
- 不对称的催化
- C-H 功能化
背景情况:
- 在有机合成中,开发高效的C-H功能化催化剂至关重要.
- 复合物是C-H功能化反应的有效碳素前体.
- 连接体设计在控制催化剂对称性和酶选择性方面发挥着关键作用.
研究的目的:
- 开发用于不对称的C-H功能化的新型二四酸催化剂.
- 研究连接物修饰对催化剂对称性和催化性能的影响.
- 在具有高反选择性的未激活的三级位点实现位点选择性C-H功能化.
主要方法:
- 修饰的2,2'-双酸 (BNP) 配体的合成和特征.
- 制备四 ((2,2'-binaphthylphosphate) 复合物
- 用X射线结晶学和计算研究来确定催化剂对称性.
- 使用三乙烯酸作为碳基前体的不对称C-H功能化反应.
主要成果:
- 成功开发了二四酸催化剂.
- 确定了Rh2 ((S-megaBNP) 4作为最佳催化剂,具有D4对称性.
- 在未被激活的三级部位获得高的C-H功能选择性.
- 证明具有特殊的催化活性,催化剂负载低 (0.0025 mol %) 和高周转率 (29,400).
结论:
- 修改后的BNP配体使得高效的二催化剂可用于不对称的C-H功能化.
- 最好的D4对称催化剂的性能优于现有的二四碳酸盐催化剂.
- 这些发现扩大了选择性分子间C-H功能化的催化剂的范围.
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