Ruthenium-Catalyzed Alkylation of Oxindole with Alcohols
作者:Thomas Jensen、Robert Madsen
DOI:10.1021/jo900341w
日期:2009.5.15
An atom-economical and solvent-free catalytic procedure for the mono-3-alkylation of oxindole with alcohols is described. The reaction is mediated by the in situ generated catalyst from RuCl3·xH2O and PPh3 in the presence of sodium hydroxide. The reactions proceed in good to excellent yields with a wide range of aromatic, heteroaromatic, and aliphatic alcohols.
描述了用于羟吲哚与醇的单-3-烷基化的原子经济且无溶剂的催化方法。该反应由RuCl 3 · x H 2 O和PPh 3在氢氧化钠存在下原位生成的催化剂介导。使用多种芳族,杂芳族和脂族醇,反应可以以良好的收率进行,收率很高。
Facile and Efficient Enantioselective Hydroxyamination Reaction: Synthesis of 3-Hydroxyamino-2-Oxindoles Using Nitrosoarenes
Sc takes action: The highly enantioselectivehydroxyaminationreaction of N‐unprotected 2‐oxindoles with nitrosoarenes has been realized using the Sc(OTf)3/L1 complex. The catalyst system exhibited remarkably broad substrate scope and high efficiency. This transformation is the first example of a chiral ScIII/enolate activating a nitrosoarene, and can be conducted on a gram scale without loss in the
Sc发挥作用:使用Sc(OTf)3 / L1络合物实现了N-未保护的2-氧吲哚与亚硝基芳烃的高度对映选择性羟基胺化反应。该催化剂体系表现出显着的底物范围和高效率。该转化是手性Sc III /烯酸酯活化亚硝基芳烃的第一个实例,并且可以以克级进行,而不会损失ee 值。
Highly Enantioselective Synthesis of 3-Amino-2-oxindole Derivatives: Catalytic Asymmetric α-Amination of 3-Substituted 2-Oxindoles with a Chiral Scandium Complex
A highly enantioselective α‐amination of 3‐substitutedoxindoles with azodicarboxylates catalyzed by a chiral Sc(OTf)3/N,N′‐dioxide complex (Tf: triflate) has been developed and affords the corresponding 3‐amino‐2‐oxindole derivatives in high yields (up to 98 %) with excellent enantioselectivities (up to 99 % ee). The procedure is capable of tolerating a relatively wide range of substrates, and excellent
Catalytic asymmetric α‐arylation of N‐unprotected 3‐substituted oxindoles with diaryliodoniumsalts has been realized by a chiral Lewis acid promoted electrophilic addition and aryl‐rearrangement process. Single C3‐arylated products containing a quaternary carbon center were generated in high enantioselectivity and reactivity.
The highly Z‐selective asymmetric conjugateaddition of 3‐substituted oxindoles to alkynyl carbonyl compounds has been developed by using scandium complexes of chiral N,N′‐dioxides under mild conditions. The thermodynamically unstable Z‐olefin derivatives were obtained in excellent yields and high enantiomeric and geometric control. The catalyst was also found to be effective in the asymmetric acetylenic