The Power of Triplet and Singlet Oxygen in Synthesis: 2-Oxindoles, 3-Hydroxy-2-oxindoles, and Isatins from Furans
作者:Myron Triantafyllakis、Kalliopi Sfakianaki、Dimitris Kalaitzakis、Georgios Vassilikogiannakis
DOI:10.1021/acs.orglett.8b01404
日期:2018.6.15
A straightforward synthesis of substituted 2-oxindoles, 3-hydroxy-2-oxindoles, and isatins has been developed. Easily accessible furans were transformed into tetrahydropyranopyrrolones by a singlet oxygen initiated cascade reaction sequence. An acid-catalyzed rearrangement, followed by aromatization, gave access to a variety of 2-oxindole motifs, which were oxidized to 3-hydroxy-2-oxindoles or isatins
已经开发了取代的2-氧吲哚,3-羟基-2-氧吲哚和靛红的直接合成方法。容易获得的呋喃通过单线态氧引发的级联反应序列转化为四氢吡咯并吡咯烷酮。酸催化的重排,然后进行芳构化,可以使用亚甲基蓝作为自由基引发剂和分子氧作为末端氧化剂将各种2-oxindole图案氧化为3-羟基-2-oxindole或靛红。