An efficient approach for the synthesis of 3-substituted-3-hydroxy-2-oxindoles has been achieved via an aldol reaction of α,β-unsaturated ketones and isatins using arginine as an organocatalyst. A range of 3-substituted-3-hydroxy-2-oxindoles were obtained in moderate to high (up to 99%) yields. These 3-substituted-3-hydroxy-2-oxindoles with an additional enone moiety provide an opportunity for further elaboration of the products and for potentially interesting biological activities. In addition, the formation of 3-substituted-3-hydroxy-2-oxindole 3a was confirmed by X-ray crystallography. The possible reaction mechanism reveals that the reaction proceeds via a double action process.
使用精
氨酸作为有机催化剂,通过 α,β-不饱和酮和
靛红的醇醛缩合反应,实现了合成 3-取代-3-羟基-2-羟
吲哚的有效方法。以中等到高(高达 99%)的产率获得了一系列 3-取代-3-羟基-2-羟
吲哚。这些带有额外烯酮部分的 3-取代-3-羟基-2-羟
吲哚为进一步精制产品和潜在有趣的
生物活性提供了机会。此外,X射线晶体学证实了3-取代-3-羟基-2-羟
吲哚3a的形成。可能的反应机理表明该反应通过双作用过程进行。