已经证明了一种新颖的串联方法,用于从查耳酮和2-氨基吡啶直接合成生物活性的3-芳基咪唑并[1,2- a ]吡啶。报道的串联反应是原子经济的,预计将通过1,4-Michael加成反应,然后进行铜催化的氧化C-N键进行。发现铜的催化量对于串联反应的成功至关重要,它改变了反应途径,提供了全新的产品。该方案被证明是方便的,因为在存在空气作为氧化剂的情况下反应平稳进行而无需任何配体。
TMSOTf-promoted reaction of heteroaromaticimines or hydroxyaminalintermediates with various enolic ketones are reported. This reaction constitutes an original and regioselective mode of alkylation of exocyclic amines of heterocyclic amidines.
Iodine-promoted oxidative coupling reaction: a simple and efficient process to access imidazo[1,2-a]pyridines from 2-aminopyridines and chalcones
作者:Meng-Ming Xing、Ming Xin、Chao Shen、Jian-Rong Gao、Jian-Hong Jia、Yu-Jin Li
DOI:10.1016/j.tet.2016.05.052
日期:2016.7
A unique and efficient approach has been developed for the synthesis of substituted imidazo[1,2-a]pyridines with aminopyridines and chalcones via a one-pot I2-induced aerobic oxidative coupling. The reported reaction proceeded though a tandem Michael addition followed by an intramolecular oxidative amination with high regioselectivity, yields and good functional group tolerance.
已经开发了一种独特且有效的方法,用于通过一锅I 2诱导的需氧氧化偶联合成具有氨基吡啶和查耳酮的取代的咪唑并[1,2- a ]吡啶。报道的反应是通过串联迈克尔加成反应进行的,然后进行分子内氧化胺化,具有较高的区域选择性,产率和良好的官能团耐受性。
A transition metal-free cascade reaction using heterogeneous tin(IV)oxide catalyzed and iodine promoted synthesis of 3-aroylimidazo[1,2-a]pyridines
作者:Nirajkumar H. Jadhav、Sachin S. Sakate、Dnyaneshwar R. Shinde、Manohar G. Chaskar、Ramdas A. Pawar
DOI:10.1016/j.tetlet.2020.152250
日期:2020.8
synthesis of 3-aroylimidazo[1,2-a]pyridines. The methodology was further extended for the one-pot three-component synthesis of 3-aroylimidazo[1,2-a]pyridines using acetophenone, benzaldehyde, and 2-aminopyridine derivatives. The present protocol describes the easy purification methodology in the synthesis of 3-aroylimidazo[1,2-a]pyridines.
在环境空气气氛下,通过SnO 2 / I 2催化体系在甲苯中使用查尔酮和2-氨基吡啶实现了3-芳基咪唑并[ 1,2 - a ]吡啶的级联合成。在3-芳基咪唑并[1,2]合成过程中,该催化剂对具有2-氨基吡啶,4-甲基2-氨基吡啶和5-甲基2-氨基吡啶的各种芳族和杂环查耳酮的广泛底物范围显示出高活性。-一个]吡啶。该方法进一步扩展为使用苯乙酮,苯甲醛和2-氨基吡啶衍生物一锅法合成3-芳基咪唑并[ 1,2 - a ]吡啶。本协议描述了3-芳基咪唑并[ 1,2 - a ]吡啶的合成中的简便纯化方法。
Copper supported on H<sup>+</sup>-modified manganese oxide octahedral molecular sieves (Cu/H-OMS-2) as a heterogeneous biomimetic catalyst for the synthesis of imidazo[1,2-a]-N-heterocycles