新型双螺环丙基吲哚支架的第一个非对映体和对映体不对称合成已经从现成的靛红作为单一起始材料完成。四个rel -(1 R ,2 R ,3 R )、rel -(1 S ,2 S ,3 R )、rel-(1 R ,2 R ,3 S ) 和rel -(1 S ,2 S , 3秒) 通过使用手性辅助控制方法在底物中进行简单切换,以出色的对映体纯度构建所需产品的构型。通过 X 射线衍射分析证实了具有三个连续的四级/三级手性中心的环加合物的绝对构型。还介绍了多功能前体 3-chlorooxindoles 的简便合成。
新型双螺环丙基吲哚支架的第一个非对映体和对映体不对称合成已经从现成的靛红作为单一起始材料完成。四个rel -(1 R ,2 R ,3 R )、rel -(1 S ,2 S ,3 R )、rel-(1 R ,2 R ,3 S ) 和rel -(1 S ,2 S , 3秒) 通过使用手性辅助控制方法在底物中进行简单切换,以出色的对映体纯度构建所需产品的构型。通过 X 射线衍射分析证实了具有三个连续的四级/三级手性中心的环加合物的绝对构型。还介绍了多功能前体 3-chlorooxindoles 的简便合成。
Organocatalytic Enantioselective Synthesis of Tetrahydro‐Furanyl Spirooxindoles via [3+2] Annulations of 3‐Hydroxyoxindoles and Cyclic Ketolactams
作者:Yue Liu、Ying Zhang、Qian‐Wei Huang、Chuan Gou、Qing‐Zhu Li、Qing‐Song Dai、Hai‐Jun Leng、Jun‐Long Li
DOI:10.1002/adsc.202100033
日期:2021.4.13
Asymmetric construction of pharmacologically interesting tetrahydrofuranyl spirooxindole frameworks has been achieved through organocatalytic [3+2] annulations of the readily available 3‐hydroxyoxindoles and pyrrolidone‐derived cyclic ketolactams. A variety of chiral spiro tetrahydrofuranyl products, which contain four contiguous stereocenters including two tetrasubstituted carbon centers, have been
access to a broad range of unnatural C2-quaternary 2-hydroxyindoxyls in high yields. The reaction proceeds via a mechanistically intriguing one-pot 1,2-hydride shift followed by autoxidation pathway. The utility of this method is demonstrated by the synthesis of a new class of bis-indoxyl spirofuran derivatives.
Organocatalytic Asymmetric Synthesis of Bridged Acetals with Spirooxindole Skeleton
作者:Megha Balha、Subhas Chandra Pan
DOI:10.1021/acs.joc.8b02156
日期:2018.12.7
The first highly diastereo- and enantioselective synthesis of bridged O,O-acetals embedded with spirooxindoles has been developed. Dioxindoles and 2-hydroxy cinnamaldehydes were employed as the reaction partners in this method. The desired products were obtained via diaryl prolinol TBS ether catalyzed Michael reaction followed by acetal formation with TFA.
The asymmetric Michael addition of dioxindoles to β-substituted nitroalkenes is reported. The bifunctional primary amine-thiourea A, by means of a non-covalent-based mode of catalysis, secures direct access to 3-substituted 3-hydroxyoxindole derivatives with high stereocontrol.
报告了二氧吲哚与 β-取代的硝基烯的不对称迈克尔加成反应。双功能伯胺-硫脲 A 通过非共价催化模式,可直接获得具有高度立体控制性的 3-取代 3-羟基吲哚衍生物。
Iron‐catalyzed one‐pot oxidation/Knoevenagel condensation reaction using air as an oxidant
A green and highly efficient iron‐catalyzed one‐pot oxidation/Knoevenagel tandem reaction for the synthesis of α, β‐unsaturated nitriles from secondary alcohols and malononitrile has been achieved. The reaction performed under mild conditions with air as an oxidant, and provided the corresponding oxidation/Knoevenagel prudocts in good to excellent yields within short times avoiding the use of noble