Asymmetric Synthesis of Chromans Through Bifunctional Enamine‐Metal Lewis Acid Catalysis
Asymmetric Synthesis of Chromans Through Bifunctional Enamine‐Metal Lewis Acid Catalysis
复制标题
双功能烯胺-金属路易斯酸催化不对称合成色满
DOI：
10.1002/chem.202200224
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Wang, Hong
中科院分区：
文献类型：
--
作者：
Davis, Jacqkis;Gharaee, Mojgan;Karunaratne, Chamini V.;Cortes Vazquez, Jose;Haynes, Mikayla;Luo, Weiwei;Nesterov, Vladimir N.;Cundari, Thomas;Wang, Hong
协同烯胺-金属刘易斯酸催化已成为构建碳-碳和碳-杂原子键形成反应的有力工具。以环己酮和水杨醛为原料，不对称合成了色满化合物，并以较高的产率（高达87%）和立体选择性（高达99%ee和11：1：1dr）合成了含有三个连续立体中心的三环色满化合物。这种困难的有机转化是通过双官能烯胺-金属刘易斯酸催化实现的。据信，水杨醛通过与金属刘易斯酸螯合而被强活化以及催化剂的双官能性质是该反应的高产率和对映选择性的原因。通过X射线晶体学确定色满产物的绝对构型。通过密度泛函（DFT）计算，研究了该反应的机理和立体选择性.
Cooperative enamine‐metal Lewis acid catalysis has emerged as a powerful tool to construct carbon‐carbon and carbon‐heteroatom bond forming reactions. A concise synthetic method for asymmetric synthesis of chromans from cyclohexanones and salicylaldehydes has been developed to afford tricyclic chromans containing three consecutive stereogenic centers in good yields (up to 87 %) and stereoselectivity (up to 99 % ee and 11 : 1 : 1 dr). This difficult organic transformation was achieved through bifunctional enamine‐metal Lewis acid catalysis. It is believed that the strong activation of the salicylaldehydes through chelating to the metal Lewis acid and the bifunctional nature of the catalyst accounts for the high yields and enantioselectivity of the reaction. The absolute configurations of the chroman products were established through X‐ray crystallography. DFT calculations were conducted to understand the mechanism and stereoselectivity of this reaction.