Phosphoric Acid Catalyzed 1,2-Rearrangements of 3-Hydroxyindolenines to Indoxyls and 2-Oxindoles: Reagent-Controlled Regioselectivity Enabled by Dual Activation
作者:Eva Schendera、Stephanie Lerch、Thorsten von Drathen、Lisa-Natascha Unkel、Malte Brasholz
DOI:10.1002/ejoc.201700085
日期:2017.6.16
A common synthetic route to indoxyl and 2-oxindole alkaloids utilizes the oxidation of indoles to 3-hydroxyindolenines, followed by acid-mediated 1,2-rearrangement. However, controlling the regioselectivity is often challenging and there is an ongoing need for new reaction conditions allowing to steer product selectivity. We report herein that phosphoric acids are ideal organocatalysts for the highly
吲哚酚和 2-羟吲哚生物碱的常见合成途径是将吲哚氧化成 3-羟基吲哚啉,然后进行酸介导的 1,2-重排。然而,控制区域选择性通常具有挑战性,并且持续需要新的反应条件来控制产物选择性。我们在本文中报告说,磷酸是 3-羟基吲哚啉至 2-羟吲哚的高度区域选择性 1,2-重排的理想有机催化剂,其有效的双重活化模式产生了可预测的产物选择性。