Diastereo- and Enantioselective Conjugate Addition of 3-Substituted Oxindoles to Nitroolefins Catalyzed by a Chiral Ni(OAc)<sub>2</sub>-Diamine Complex under Mild Conditions
assembled from an enantiomerically pure diamine ligand and Ni(OAc)2 efficiently generates chiral metal enolates derived from 3-substituted oxindoles bearing an N-1 carbonyl group. The enolates smoothly undergo diastereo- and enantioselective conjugate addition to a wide range of nitroolefins under mild reaction conditions, furnishing 3,3-disubstituted oxindole products bearing twovicinal quaternary/tertiary
Amino-Indanol-Catalyzed Asymmetric Michael Additions of Oxindoles to Protected 2-Amino-1-nitroethenes for the Synthesis of 3,3′-Disubstituted Oxindoles Bearing α,β-Diamino Functionality
An organocatalytic asymmetricMichaeladdition reaction of 3-substituted oxindoles to protected 2-amino-1-nitroethenes has been developed. The reaction is catalyzed by a simple and readily available amino-indanol derivative and affords the desired products in very high yields (up to 99%) with excellent diastereoselectivities (up to >99:1) and very good enantioselectivities (up to 90%). Significantly
Catalytic Enantioselective Dearomatization/Rearomatization of 2-Nitroindoles to Access 3-Indolyl-3′-Aryl-/Alkyloxindoles: Application in the Formal Synthesis of Cyclotryptamine Alkaloids
作者:Wei-Cheng Yuan、Xiao-Jian Zhou、Jian-Qiang Zhao、Yong-Zheng Chen、Yong You、Zhen-Hua Wang
DOI:10.1021/acs.orglett.0c02350
日期:2020.9.18
The first catalyticenantioselective dearomatization/rearomatization of 2-nitroindoles triggered by the Michael addition of 3-monosubstituted oxindoles was established. A wide range of 3-indolyl-3′-alkyloxindoles (up to 99% yield, 97% ee) and 3-indolyl-3′-aryloxindoles (up to 95% yield, 99% ee) were obtained by using an organocatalyst. This method provides an unprecedented strategy to access structurally
Catalytic Double Stereoinduction in Asymmetric Allylic Alkylation of Oxindoles
作者:Barryâ M. Trost、Yong Zhang
DOI:10.1002/chem.200902770
日期:2010.1.4
A highly regio‐, diastereo‐, and enantioselective allylicalkylation reaction of 3‐monosubstituted oxindoles catalyzed by molybdenum is described. The reaction is affected by the electronic and steric variations of the nucleophile. The use of appropriate N‐protecting group is particularly important for achieving high regio‐ and diastereoselectivity. Products from this reaction, containing vicinal quaternary‐tertiary
描述了钼催化的 3-单取代羟吲哚的高度区域、非对映和对映选择性烯丙基烷基化反应。该反应受到亲核试剂的电子和空间变化的影响。使用适当的 N 保护基团对于实现高区域和非对映选择性特别重要。该反应的产物含有邻位季-叔立构中心,是有价值的合成中间体,应该在生物碱合成中得到应用。
Organocatalytic Stereoselective Mannich Reaction of 3-Substituted Oxindoles
The asymmetric Mannich reaction of 3-substituted oxindoles and N-Boc imines was investigated for the first time, employing bifunctional thiourea-tertiary amine organocatalysts based on DPEN scaffold. The novel transformations exhibited high diastereoselectivities, and the Mannich adducts bearing adjacent quaternary and tertiary chiral centers were generally obtained in good to excellent enantioselectivities (up to 95% ee).