4045-03-8Relevant academic research and scientific papers
A multi pathway coupled domino strategy: I2/ TBHP-promoted synthesis of imidazopyridines and thiazoles via sp3, sp2 and sp C-H functionalization
Feng, Lei,Li, Shichen,Ma, Chen,Wang, Xinfeng,Wang, Yishou,Yao, Yiming
, p. 5919 - 5927 (2022/03/31)
I2/TBHP-promoted, one-pot, multi pathway synthesis of imidazopyridines and thiazoles has been achieved through readily available ethylarenes, ethylenearenes and ethynearenes. I2/TBHP as an initiator and oxidant is used to realize the C-H functionalization of this domino reaction. Simple and available starting materials, wide range of functional group tolerance, high potential for drug activity of the products and application in production are the advantageous features of this method.
Design, synthesis and anticancer activity of sulfenylated imidazo-fused heterocycles
Chitrakar, Ravi,Rawat, Deepa,Sistla, Ramakrishna,Subbarayappa, Adimurthy,Vadithe, Lakshma Nayak
supporting information, (2021/08/13)
We report herein, the design, synthesis and study of anticancer properties of sulfenylated 2-phenylimidazo[1,2-a]pyridines and their analogues. A set of twenty sulfenylated imidazo[1, 2-a]pyridine derivatives were synthesized. Whereby elusive amendments to the imidazo[1,2-a]pyridine motif confer dramatic changes in functional affinity of a novel action to modulate anticancer activity in seven different human cancer cell lines i.e.: MDA MB 231 (breast), HepG2 (liver), Hela (cervical), A549 (lung), U87MG (glioblastoma), SKMEL-28 (skin melanoma) and DU-145 (prostate) by employing MTT assay. Among the series, compounds 4e (naphthalene), 4f (styrene) and 4h (thiomethyl) showed potent activity towards human liver cancer cells HepG2. Cell cycle analysis results revealed that these compounds arrested the cell cycle at G2/M phase and induced apoptosis in human liver cancer cells HepG2. It was further confirmed by Hoechst staining, Measurement of mitochondrial membrane potential (ΔΨm) and Annexin V-FITC assay.
Electrochemical Oxidative C3 Acyloxylation of Imidazo[1,2- a]pyridines with Hydrogen Evolution
Yuan, Yong,Zhou, Zhilin,Zhang, Lin,Li, Liang-Sen,Lei, Aiwen
supporting information, p. 5932 - 5936 (2021/08/16)
The C3-functionalized imidazo[1,2-a]pyridines are versatile nitrogen-fused heterocycles; however, the methods for the C3 acyloxylation of imidazo[1,2-a]pyridines have never been reported. Herein we demonstrate the electrochemical oxidative C3 acyloxylation of imidazo[1,2-a]pyridines for the first time. Notably, by using electricity, the electrochemical oxidative C3 acyloxylation of imidazo[1,2-a]pyridines was carried out under mild conditions. Moreover, in addition to aromatic carboxylic acids, alkyl carboxylic acids were also competent substrates.
Micellar Catalysis: Visible-Light Mediated Imidazo[1,2-a]pyridine C—H Amination with N-Aminopyridinium Salt Accelerated by Surfactant in Water
Yang, Zhonglie,Cao, Kun,Peng, Xiaoyan,Lin, Li,Fan, Danchen,Li, Jun-Long,Wang, Jingxia,Zhang, Xiaobin,Jiang, Hezhong,Li, Jiahong
supporting information, p. 3347 - 3352 (2021/10/20)
A light-promoted metal-free protocol for the amination of imidazo[1,2-a]pyridines with N-aminopyridinium salt by the assistance of surfactants in water was reported, charactering mild and environmentally benign conditions, as well as great functional grou
Molecular iodine enabled generation of iminyl radicals from oximes: A facile route to imidazo[1,2-a]pyridines and its regioselective C-3 sulfenylated products from simple pyridines
Singh, Deepak,Chowdhury, Soumyadeep Roy,Pramanik, Shyamal,Maity, Soumitra
, (2021/04/22)
An iodine promoted simple and environment friendly protocol has been developed to access imidazo[1,2-a]pyridines from unfunctionalized pyridines and oxime esters. This straightforward method efficiently converts the substrates into corresponding products affording moderate to good yields with large functional group tolerance. Additionally extensive investigation revealed that regioselective domino C-3 methyl sulfenylated imidazo[1,2-a]pyridines were also accessible first time from pyridines and oxime esters in DMSO solvent. The reaction operates through metal-free generation of iminyl radicals from easily accessible oxime esters, to build up the second heterocyclic ring on pyridines.
Synthetic method of imidazopyridine compounds
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Paragraph 0054-0067, (2021/03/24)
The invention provides a novel method for synthesizing imidazopyridine compounds. According to the invention, aminopyridine compounds and sulfur ylide are used as original reaction substrates, iron phthalocyanine (FeIIPc) is used as a catalyst, and a series of the imidazopyridine compounds are obtained under the condition that the advantages of mildness, greenness, high efficiency, wide substrateuniversality and the like are achieved.
A simple and efficient route to 2-arylimidazo[1,2-a]pyridines and zolimidine using automated grindstone chemistry
Das, Dharmendra,Bhutia, Zigmee T.,Panjikar, Padmini C.,Chatterjee, Amrita,Banerjee, Mainak
supporting information, p. 4099 - 4107 (2020/09/09)
A green and efficient mechanochemical method for the synthesis of a series of 2-arylimidazo[1,2-a]pyridines was developed using an electrical grinder. I2 catalyzed mechanochemical grinding facilitates the cyclocondensation reaction between various aryl methyl ketones and 2-aminopyridines to afford 2-arylimidazo[1,2-a]pyridines in good yields at ambient temperature. The method was successfully used for the gram-scale synthesis of a marketed drug, zolimidine. The noticeable advantages of this environmentally sustainable protocol include mild conditions, simple instrumentation, inexpensive catalyst, atom economy, short reaction time etc.
Multicomponent Synthesis of Imidazo[1,2- a]pyridines: Aerobic Oxidative Formation of C-N and C-S Bonds by Flavin-Iodine-Coupled Organocatalysis
Okai, Hayaki,Tanimoto, Kazumasa,Ohkado, Ryoma,Iida, Hiroki
supporting information, p. 8002 - 8006 (2020/11/02)
Herein, we report an aerobic oxidative C-N bond-forming process that enables the facile synthesis of imidazo[1,2-a]pyridines and takes advantage of a coupled organocatalytic system that uses flavin and iodine. Furthermore, the dual catalytic system can be applied to the one-pot, three-step synthesis of 3-thioimidazo[1,2-a]pyridines from aminopyridines, ketones, and thiols.
CuCl2-catalyzed N[sbnd]O bond cleavage of oxime esters: Approach to imidazoheterocycles and furo[3,2-c]chromenyl fused imidazoles
Gudimella, Santosh K.,Kaur, Amanpreet,Kumar, Ram,Samanta, Sampak
supporting information, (2020/07/08)
An articulate approach to a diverse set of imidazoheterocycles in good to high yields via a copper-catalyzed aza-annulation of several oxime esters with a group of 2-amino-azaarenes was developed. The above cyclization reaction probably proceeds via a single electron transfer process which embodies a new technique for creating two new C[sbnd]N bonds for imidazole ring synthesis. Gratifyingly, the implementation of this chemistry could be further stretched to the synthesis of a novel class of fused imidazoles bearing a furo[3,2-c]chromene moiety via a sequential C[sbnd]N bond formation, followed by C(sp2)-H functionalization/5-endo-dig-oxacyclization (C[sbnd]C and C[sbnd]O bonds) of in situ produced fused imidazoles with cyclic enynones in the presence of copper(II) as a π-electrophilic Lewis acid catalyst.
Electrochemically initiated intermolecular C-N formation/cyclization of ketones with 2-aminopyridines: An efficient method for the synthesis of imidazo[1,2-: A] pyridines
Feng, Mei-Lin,Li, Shu-Qi,He, Hui-Zi,Xi, Long-Yi,Chen, Shan-Yong,Yu, Xiao-Qi
supporting information, p. 1619 - 1624 (2019/04/08)
Electrochemical intermolecular C-N formation/cyclization of ketones with 2-aminopyridines using catalytic hydriodic acid as the redox mediator was developed, providing imidazo[1,2-a]pyridines under more environmentally benign conditions. The reaction proceeds in a simple undivided cell, using low toxic ethanol as the solvent, without external oxidants, and exhibits high atom economy. A variety of ketones including acetophenones, unsatruated and alkyl ketones are amenable to this reaction, affording the corresponding products in moderate to excellent yields. A three-component tandem reaction realizing C-N, C-S/C-Se bond formation can also be achieved under standard conditions.
