Ketone–ketone cross-aldolreaction of isatins and unactivated ketones was catalyzed by glucose-containing imidazolium salt β-1-imidazole-2,3,4,6-tetra- o -hydroxy- d -glucopyranosyl bromide in neutral condition to generate 3-alkyl-3-hydroxyindolin-2-ones in excellent yield.
含葡萄糖的咪唑鎓盐β-1-咪唑-2,3,4,6-四氢呋喃-丁酮催化靛红与未活化酮的酮-酮交叉羟醛反应。 Ø -羟基- d -葡糖吡喃糖基溴在中性条件下生成3-烷基-3-羟基吲哚-2-酮的产率很高。
“On Water” Catalytic Aldol Reaction between Isatins and Acetophenones: Interfacial Hydrogen Bonding and Enamine Mechanism
“On water” catalytic aldol reaction catalyzed by polyetheramine (D230) has been developed for easy access to 3-substituted 3-hydroxyindolin-2-ones through the reaction between various substituted isatins and acetophenones/cyclic ketones in high yields under room temperature. Systematic mechanism investigation uncovers the secret for the on water catalytic aldol reaction: comparison of the heterogeneous
已经开发了通过聚醚胺(D230)催化的“水上”催化醛醇缩合反应,可通过在室温下高产率地使各种取代的靛红与乙酰苯/环酮之间的反应轻松获得3-取代的3-羟基吲哚-2-酮。系统的机理研究揭示了水催化醛醇缩合反应的奥秘:比较异构反应和均相反应的情况,产率分别为95%和20%,表明水上反应占主导。当将水添加到CDCl 3中时,基于C2和C3的13 C NMR信号的下场位移,测试了isatin与H 2 O之间的界面氢键靛红溶液;路易斯碱聚醚胺D230通过烯胺机制催化醛醇缩醛反应,该机制已通过原位NMR和ESI-MS分析验证。
Superacid-Promoted synthesis of spirooxindoles
作者:Jacob C. Hood、Hien Vuong、Douglas A. Klumpp
DOI:10.1016/j.tetlet.2023.154817
日期:2023.11
provide Aldol products (3-hydroxy-3-(2-oxo-2-arylethyl)indolin-2-ones) from reaction with diethylamine and these substrates react in excess superacid to provide good yields of spirooxindoles. The resulting spirooxindoles are shown to be useful scaffolds in the syntheses of related urea, carbamate, amido, and benzylderivatives. A mechanism of cyclization is proposed involving a superelectrophilic Nazarov