A Facile One-Step Synthesis of 2-Arylindazoles via Reductive Cyclization of<i>N</i>-(2-nitroarylidene)amines
作者:Wei Lin、Minghua Hu、Xian Feng、Chengpao Cao、Zhibin Huang、Daqing Shi
DOI:10.1002/jhet.2221
日期:2015.7
A mild and efficient synthesis of 2‐arylindazole derivatives via the reductivecyclization of nitro‐aryl substrates mediated by a low‐valent titanium reagent (TiCl4/Sm/Et3N) has been developed. The attractive features of the current method include an N–N bond formation and the selective reduction of the C = N bond and nitro group, both of which were easily achieved in one‐pot by controlling the pH
通过低价钛试剂(TiCl 4 / Sm / Et 3 N)介导的硝基芳基底物的还原环化,可以温和有效地合成2-芳基吲唑衍生物。当前方法的吸引人的特征包括N–N键的形成以及C = N键和硝基的选择性还原,通过控制反应混合物的pH值,很容易在一个锅中完成这两个操作。
Transition Metal-Free α-C(<i>sp</i><sup>3</sup>)H Bond Functionalization of Amines by Oxidative Cross Dehydrogenative Coupling Reaction: Simple and Direct Access to C-4-Alkylated 3,4-Dihydroquinazoline Derivatives
A transitionmetal-freecatalyticsystem has been developed for the cross dehydrogenative coupling of amines with nitroalkanes under mild condition employing potassium iodide/tert-butyl hydrogen peroxide catalyticsystem. This methodology was further extended for the construction of biologically important N-heterocycles, namely, 3,4-dihydroquinazoline derivatives. This novel strategy provides a simple
Iron-catalyzed C–C bond formation via cross dehydrative coupling reaction of N-heterocyclic aminols with electron rich arenes: facile access to C4-aryl-dihydroquinazolines
The direct coupling of sp(3) C-OH bond of N -heterocyclic aminols with sp(2) C-H bond of electron rich arenes have been achieved via iron catalyzed dehydrative cross coupling strategy. This novel protocol provides an efficient and straight forward route to access biologically important C4-aryl-3,4dihydroquinazoline derivatives through the reaction of C4-hydroxy-3,4-dihydroquinazolineiaminol with phenol and aniline derivatives under mild reaction conditions. (C) 2015 Elsevier Ltd. All rights reserved.