Selective Synthesis of Pyrazolo[1,2-<i>a</i>]pyrazolones and 2-Acylindoles via Rh(III)-Catalyzed Tunable Redox-Neutral Coupling of 1-Phenylpyrazolidinones with Alkynyl Cyclobutanols
作者:Yuanshuang Xu、Mengyang Shen、Xinying Zhang、Xuesen Fan
DOI:10.1021/acs.orglett.0c01475
日期:2020.6.19
An unprecedented divergent synthesis of pyrazolo[1,2-a]pyrazolones and 2-acylindoles via Rh(III)-catalyzed [4 + 1] or [3 + 2] annulation of 1-phenylpyrazolidinones with alkynyl cyclobutanols through redox-neutral multiple bond activation by using −NH and −OH units as directing groups is presented. Notably, different annulation reactions were selectively achieved by simply adjusting the reaction conditions
通过Rh(III)催化1-苯基吡唑烷二酮与炔基环丁醇通过氧化还原-中性多键的环化反应,空前地合成吡唑并[1,2- a ]吡唑并酮和2-酰基吲哚。提出了通过使用-NH和-OH单元作为导向基团的活化。值得注意的是,通过简单地调节反应条件选择性地实现了不同的环化反应。这些方法具有操作简单,容易获得的底物和高区域选择性/化学选择性等特点,可以在相关领域广泛应用。
Rh(III)-catalyzed [4+1] annulation and ring opening for the synthesis of pyrazolo[1,2-a] indazole bearing a quaternary carbon
A Rhodium(III)-catalyzed [4+1] annulation and ring opening of 1 alkynylcyclobutanols with pyrazolidinones to access pyrazolo[1,2-a] indazoles bearing a quaternary carbon center was described. This method features high functional group tolerability and afforded pyrazolo[1,2-a] indazoles in moderate to good yield under mild conditions. (C) 2020 Elsevier Ltd. All rights reserved.