区域选择性和灾难选择性铁催化 [4+4] 循环添加 1,3-二烯
C Rose Kennedy1, Hongyu Zhong1, Rachel L Macaulay1
1Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States.
Journal of the American Chemical Society
|May 8, 2019
概括
这项研究引入了新型铁催化剂,用于高效的 [4+4] 循环二氧化和循环添加二烯. 这些催化剂可以控制立体异构体的形成,并且在大规模上有效.
科学领域:
- 有机金属化学
- 催化剂
- 有机合成
背景情况:
- 1,3-二烯的 [4+4] 循环二氧化和循环添加是有机合成中的重要反应.
- 开发这些转型的有效和选择性催化剂仍然是一个关键挑战.
- 铁复合物提供了一个有前途的,地球上丰富的替代品.
研究的目的:
- 开发单组件铁预催化剂,用于单替代的1,3-dienes的 [4+4]-环氧化和分子间交叉 [4+4]-环氧化.
- 在形成环氧八二烯产品时实现高区域选择性和扩散选择性.
- 能够通过催化剂控制特定的二聚体 (cis或trans).
主要方法:
- 含有2-胺连体的单元铁前催化剂的合成和表征
- 催化剂在 [4+4] 循环二聚化和交叉 [4+4] 循环添加反应中的应用.
- 结构和光谱分析,包括单晶X射线衍射,Mösbauer光谱,磁性测量和DFT计算.
- 使用动力学分析,同位素效应研究和现场光谱学的机制研究.
主要成果:
- 在循环八二烯产品的形成中实现了高区域选择性.
- 催化剂控制允许使用4-替代代因子选择性合成cis-或trans-diastereomers.
- 反应与常见的有机功能组相容,可扩展到多克量 (> 100 g).
- 鉴定发现了具有高自旋铁 (I) 中心与基离子结合的催化相关的S=1铁复合体.
- 机理学研究支持了一种涉及二烯氧化循环的途径,决定了选择性.
结论:
- 单元铁预催化剂能够有效和选择性地进行1,3-dienes的 [4+4]-循环二氧化和循环添加.
- 开发的催化剂可以精确控制区域和异体选择性,包括对特定异体的催化剂控制的访问.
- 这些发现为铁催化循环添加机制提供了宝贵的见解,并为有机合成的实际应用铺平了道路.
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