Novel Ring Contraction of 3-Hydroxy-2,4(1H,3H)-quinolinediones in Aqueous Alkali. The First Convenient Route to 2-Hydroxyindoxyls
摘要:
Ring contraction of 3-hydroxy-2,4(1H,3H)-quinolinediones (1) in aqueous potassium hydroxide resulted in the formation of 2-hydroxyindoxyls and/or dioxindoles. The choice of N-substituent and the reaction conditions govern the chemoselectivity of the reaction. N-Phenyl-substituted derivatives 1 give 2-hydroxyindoxyls, while N-alkyl- and N-benzyl-substituted derivatives afford the corresponding dioxindols. On the basis of byproduct analysis, as well as independent experiments, the most plausible reaction mechanism is proposed.
Novel Ring Contraction of 3-Hydroxy-2,4(1<i>H</i>,3<i>H</i>)-quinolinediones in Aqueous Alkali. The First Convenient Route to 2-Hydroxyindoxyls
作者:Stanislav Kafka、Antonín Klásek、Janez Košmrlj
DOI:10.1021/jo015786d
日期:2001.9.1
Ring contraction of 3-hydroxy-2,4(1H,3H)-quinolinediones (1) in aqueous potassium hydroxide resulted in the formation of 2-hydroxyindoxyls and/or dioxindoles. The choice of N-substituent and the reaction conditions govern the chemoselectivity of the reaction. N-Phenyl-substituted derivatives 1 give 2-hydroxyindoxyls, while N-alkyl- and N-benzyl-substituted derivatives afford the corresponding dioxindols. On the basis of byproduct analysis, as well as independent experiments, the most plausible reaction mechanism is proposed.
Domino Grignard Addition and Oxidation for the One-Pot Synthesis of C2-Quaternary 2-Hydroxyindoxyls
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.