Controlled Diastereo- and Enantioselection in a Catalytic Asymmetric Aziridination
Controlled Diastereo- and Enantioselection in a Catalytic Asymmetric Aziridination
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DOI：
10.1021/ja1038648
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发表时间：
2010-09-29
影响因子：
15
通讯作者：
Wulff, William D.
中科院分区：
文献类型：
--
作者：
Desai, Aman A.;Wulff, William D.
已知由 VANOL 和 VAPOL 配体制备的手性聚硼酸酯基布朗斯台德酸可催化二芳基甲基亚胺与重氮酯的反应，生成顺式氮丙啶。在目前的工作中，这种相同的催化剂被证明可以催化相同的亚胺与重氮乙酰胺的反应，产生具有与顺式氮丙啶相同的高不对称诱导的反式氮丙啶，从而能够开发出前所未有的通用催化不对称氮丙啶化方案。底物范围广泛，包括由富电子和缺电子芳香醛以及1度、2度和3度脂肪醛制备的亚胺。发现亚胺加成的面选择性与重氮化合物无关。当形成顺式氮丙啶时，(S)-VANOL或(S)-VAPOL衍生的催化剂将导致重氮酯和重氮乙酰胺两者添加到亚胺的Si面，并且当形成反式氮丙啶时，两者都添加到亚胺的Re面。
Chiral polyborate based Bronsted acids prepared from the VANOL and VAPOL ligands are known to catalyze the reaction of diarylmethyl imines with diazoesters to give cis-aziridines. In the present work, this same catalyst is shown to catalyze the reaction of the same imines with diazoacetamides to give trans-aziridines with the same high asymmetric inductions as seen with cis-aziridines, enabling the development of an unprecedented universal catalytic asymmetric aziridination protocol. The substrate scope is broad and includes imines prepared from both electron-rich and electron-poor aromatic aldehydes and also from 1 degrees, 2 degrees, and 3 degrees aliphatic aldehydes. The face selectivity of the addition to the imine was found to be independent of the diazo compounds. The (S)-VANOL or (S)-VAPOL derived catalyst will cause both diazoesters and diazoacetamides to add to the Si-face of the imine when cis-aziridines are formed and both to add to the Re-face of the imine when trans-aziridines are formed.