One-Pot, Two-Step Synthesis of Imidazo[1,2-a]benzimidazoles via A Multicomponent [4 + 1] Cycloaddition Reaction
摘要:
A one-pot, two-step synthesis of imidazo[1,2-a]benzimidazoles has been achieved by a three-component reaction of 2-aminobenzimidazoles with an aromatic aldehyde and an isocyanide. The reaction involving condensation of 2-aminobenzimidazole with an aldehyde is run under microwave activation to generate an imine intermediate under basic conditions which then undergoes [4 + 1] cycloaddition with an isocyanide.
提出了前所未有的两步,一锅法合成苯并咪唑并二嗪5,5-二氧化物。当在热条件下仅形成稠合的苯并咪唑[1,2- b ] [1,2,4]噻二嗪时,已经达到了基于反应条件的区域选择性,而苯并咪唑[2,1- c ] [1,2,4]噻二嗪则在热条件下形成。仅在微波辐射下产生。该方案的显着特征包括2-氨基苯并咪唑与邻卤代磺酰氯的区域选择性磺酰化,随后形成NC键。这些稠合的区域异构体的酸形式已用于引入新型的含胍的异香豆素骨架。
A Novel Mechanistic Study on Ultrasound-Assisted, One-Pot Synthesis of Functionalized Benzimidazo[2,1-<i>b</i>]quinazolin-1(1<i>H</i>)-ones
作者:Li-Hsun Chen、Tsai-Wen Chung、Bharat D. Narhe、Chung-Ming Sun
DOI:10.1021/acscombsci.5b00186
日期:2016.3.14
Ultrasound-assisted synthesis of benzimidazo[2,1-b]quinazolin-1(1H)-ones was achieved via piperidine-catalyzed three-component reaction of 2-aminobenzimidazoles, an aromatic aldehyde, and 1,3-dione in aqueous isopropanol. This mechanism was first suspected following our identification of unusual reaction intermediates in a one-pot reaction. An unprecedented coupling reaction, it involved a nucleophilic
通过哌啶催化的2-氨基苯并咪唑,芳香族醛和1,3-二酮在异丙醇水溶液中的三组分反应实现苯并咪唑并[2,1 - b ]喹唑啉-1(1 H)-的超声辅助合成。在我们确定了一锅反应中不寻常的反应中间体之后,首先怀疑了这种机制。前所未有的偶联反应,它涉及2-氨基苯并咪唑对原位生成的迈克尔加合物的亲核攻击,然后发生电环形成反应。与普遍接受的机理相反,2-氨基苯并咪唑与Knoevenagel加合物的直接反应不能释放目标化合物。
Copper catalyzed aerobic oxidative cyclization and ketonization: one pot synthesis of benzoimidazo[1,2-a]imidazolones
作者:Manikandan Selvaraju、Tzuen-Yang Ye、Chia-Hsin Li、Pei-Heng Ho、Chung-Ming Sun
DOI:10.1039/c6cc01828a
日期:——
A highly efficientsynthesis of benzoimidazo[1,2-a]imidazolone through a novel oxidative 5-exo-dig cyclization-ketonization cascade of 2-aminobenzimidazole, aldehyde and terminalalkyne has been explored underaerobicconditions.
在有氧条件下,通过2-氨基苯并咪唑,醛和末端炔的新型5 - exo -dig环化-酮化级联反应,高效合成了苯并咪唑并[1,2- a ]咪唑酮。