Asymmetric Aza-Diels Alder Reaction with Ion-Paired ; Iron Lewis Acid ; Brønsted Acid Catalyst
Asymmetric Aza-Diels Alder Reaction with Ion-Paired ; Iron Lewis Acid ; Brønsted Acid Catalyst
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离子对不对称 Aza-Diels Alder 反应；
DOI：
10.1002/chem.201901563
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
and Seijiro Matsubara
中科院分区：
文献类型：
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作者：
Rei Tomifuji;Takuya Kurahashi;and Seijiro Matsubara
通过使用由FeBr 3和手性磷酸原位制备的[FeBr 2]+[FeBr 4]−组合，实现了在简单二烯（非Danishefsky型富电子二烯）的不对称氮杂Diels-Alder反应中具有离子配对的刘易斯酸和Brønsted酸的多重活化催化剂的开发和使用。高活性离子配对的刘易斯酸[FeBr 2]+[FeBr 4]−和手性布朗斯台德酸的协同效应对于促进具有高转换频率和高对映体选择性的反应是重要的。使用基于同步加速器的X射线吸收精细结构测量和理论研究证实了多重活化催化剂体系。该研究表明，所开发的催化剂不仅通过离子配对的刘易斯酸和布朗斯台德酸提供的相互作用，而且还通过非共价相互作用促进反应。
The development and use of a multiple‐activation catalyst with ion‐paired Lewis acid and Brønsted acid in an asymmetric aza‐Diels–Alder reaction of simple dienes (non‐Danishefsky‐type electron‐rich dienes) was achieved by utilizing the [FeBr2]+[FeBr4]−combination prepared in situ from FeBr3and chiral phosphoric acid. Synergistic effects of the highly active ion‐paired Lewis acid [FeBr2]+[FeBr4]−and a chiral Brønsted acid are important for promoting the reaction with high turnover frequency and high enantioselectivity. The multiple‐activation catalyst system was confirmed using synchrotron‐based X‐ray absorption fine structure measurements, and theoretical studies. This study reveals that the developed catalyst promoted the reaction not only by the interaction offered by the ion‐paired Lewis acid and the Brønsted acid but also noncovalent interactions.