Chemoselective [3 + 2] annulation of oxime acetate with 2-aryl-3-ethoxycarbonyl-pyrroline-4,5-dione: an entry to pyrrolo[2,3-<i>b</i>]pyrrole derivatives
A novel chemoselective [3 + 2] annulation reaction of easily accessible ketoxime acetate with 2-aryl-3-ethoxycarbonyl pyrroline-4,5-dione has been developed for the synthesis of unknown pyrrolo[2,3-b]pyrrole frameworks. This method involves copper-mediated N–O bond cleavage followed by the formation of carbon–carbon and carbon–nitrogen bonds. This operationally simple protocol provides broader functional
Copper-Catalyzed Aerobic Oxidative Cyclization of Ketoxime Acetates with Pyridines for the Synthesis of Imidazo[1,2-a]pyridines
作者:Zhi-Hui Ren、Zheng-Hui Guan、Mi-Na Zhao、Yukun Yi、Yao-Yu Wang
DOI:10.1055/s-0035-1561950
日期:——
copper(I)-catalyzed aerobic oxidative coupling of ketoximeacetates with simple pyridines for the synthesis of imidazo[1,2-a]pyridines has been developed. This reaction tolerates a wide range of functional groups and it affords a series of valuable imidazo[1,2-a]pyridines in high yields under mild conditions. A copper(I)-catalyzed aerobic oxidative coupling of ketoximeacetates with simple pyridines for the synthesis
摘要 已开发出铜(I)催化的酮肟肟乙酸酯与简单的吡啶的好氧氧化偶联,用于合成咪唑并[1,2- a ]吡啶。该反应可耐受各种官能团,并且在温和条件下以高收率提供了一系列有价值的咪唑并[1,2- a ]吡啶。 已开发出铜(I)催化的酮肟肟乙酸酯与简单的吡啶的好氧氧化偶联,用于合成咪唑并[1,2- a ]吡啶。该反应可耐受各种官能团,并且在温和条件下以高收率提供了一系列有价值的咪唑并[1,2- a ]吡啶。
Copper(0)/PPh<sub>3</sub>-Mediated Bisheteroannulations of <i>o</i>-Nitroalkynes with Methylketoximes Accessing Pyrazo-Fused Pseudoindoxyls
作者:Huanxin Meng、Zhenhua Xu、Zhonghua Qu、Huawen Huang、Guo-Jun Deng
DOI:10.1021/acs.orglett.0c02180
日期:2020.8.7
A copper(0)/PPh3-mediated cascade bisheteroannulation reaction of o-nitroalkynes with methylketoximes has been developed that provides viable access to a diverse range of pyrazo-fused pseudoindoxyl compounds. Synthetically useful functional groups including sensitive C–I bonds are compatible with this system. Mechanistic studies suggest a reaction cascade involving sequential PPh3-mediated deoxygenative
catalyzed transformations of O-acyl oximes to various N-heterocycles are well established. Herein, we report a catalyst free, oxime carboxylate based, three-component condensation method to access mono- and disubstituted pyrimidines. A broad range of substituted pyrimidines were prepared in moderate to excellent yields. Control experiments reveal that in situ generated formamidine is the key intermediate.
We describe herein a palladium-catalyzed Heck-type reaction of O-acetyl ketoximes and allylicalcohols to pyridines. This protocol allows robust synthesis of pyridines and azafluorenones in good to excellent yields with...