Palladium and copper catalyzed cyclizations of hydrazine derived Ugi products: facile synthesis of substituted indazolones and hydroxytriazafluorendiones
作者:Sebastian J. Welsch、Cédric Kalinski、Michael Umkehrer、Günther Ross、Jürgen Kolb、Christoph Burdack、Ludger A. Wessjohann
DOI:10.1016/j.tetlet.2012.02.095
日期:2012.5
Indazolones are medicinally relevant targets. Herein we disclose an improved synthesis to N′-(acetamido-2-yl)-substituted indazolones with four points of diversity introduced by Ugi-[M]-amination and -amidation. The ring closure can be achieved by either conventional palladium catalysis or with a ligandless copper protocol. When α-unbranched isocyanides were employed the sole cyclization products of
吲唑酮是医学上相关的靶标。在本文中,我们公开了通过Ugi- [M]-氨基化和-酰胺化引入的具有四个多样性点的N '-(乙酰氨基-2-基)-取代的吲唑酮的合成方法。闭环可以通过常规的钯催化或无配体的铜方案来实现。当使用α-非支化异氰酸酯时,铜催化反应的唯一环化产物是迄今未描述的2-羟基-3 H -3,4a,9a-三氮杂芴-4,9-二酮。