A novel and versatile method for the synthesis of 2H-imidazoles via iron-catalyzed [3 + 2] annulation from readily available oxime acetates with vinyl azides has been developed. This denitrogenative process involved N–O/N–N bond cleavages and two C–N bond formations to furnish 2,4-substituted 2H-imidazoles. This protocol was performed under mild reaction conditions and needed no additives or ligands
acetates and xanthates for the synthesis of thiazol-2-yl ethers with remarkable regioselectivity has been developed. Various oxime acetates, whether derived from aryl ketones or alkyl ketones, or natural product cores are suitable for this conversion. Unique dihydrothiazoles were also obtained when both reaction sites were methine. Mechanistic studies indicated that imino copper(III) intermediates were involved
Divergent Iron-Catalyzed Coupling of<i>O</i>-Acyloximes with Silyl Enol Ethers
作者:Hai-Bin Yang、Nicklas Selander
DOI:10.1002/chem.201605636
日期:2017.2.3
An iron‐catalyzedcoupling reaction of O‐acyloximes and O‐benzoyl amidoximes with silyl enol ethers is reported. The protocol provides access to functionalized pyrroles, 1,6‐ketonitriles, pyrrolines and imidazolines via carbon‐centered radicals generated from an initially formed iminyl radical. The intramolecular cyclization and ring‐opening processes of the iminyl radical take place preferentially
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.
Copper-catalyzed radical/radical cross-coupling of ketoxime carboxylates with 4-hydroxycoumarins: A novel synthesis of furo[3,2-c]-coumarins
作者:Mingchuang He、Zhaohua Yan、Wangyang Wang、Fuyuan Zhu、Sen Lin
DOI:10.1016/j.tetlet.2018.09.007
日期:2018.10
A novel and efficient strategy for the synthesis of furo[3,2-c]coumarins has been developed via copper-catalyzed radical/radical cross-coupling of ketoxime carboxylates with 4-hydroxycoumarins. This redox-neutral reaction allows smooth and selective synthesis of 2-substituted, 3-substituted, 2,3-disubstituted and 2,3-fused polycyclic furo[3,2-c]coumarins.
通过铜催化酮肟肟酸酯与4-羟基香豆素的自由基/自由基交叉偶联,已经开发了一种新型有效的合成呋喃[3,2- c ]香豆素的策略。该氧化还原中性反应允许2-取代,3-取代,2,3-二取代和2,3-稠合的多环呋喃[3,2- c ]香豆素的平滑和选择性合成。