347-12-6Relevant 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.
Oxidation Potential-Guided Electrochemical Radical-Radical Cross-Coupling Approaches to 3-Sulfonylated Imidazopyridines and Indolizines
Kim, Wansoo,Kim, Hun Young,Oh, Kyungsoo
, p. 15973 - 15991 (2021/07/26)
Oxidation potential-guided electrochemical radical-radical cross-coupling reactions between N-heteroarenes and sodium sulfinates have been established. Thus, simple cyclic voltammetry measurement of substrates predicts the likelihood of successful radical-radical coupling reactions, allowing the simple and direct synthetic access to 3-sulfonylated imidazopyridines and indolizines. The developed electrochemical radical-radical cross-coupling reactions to sulfonylated N-heteroarenes boast the green synthetic nature of the reactions that are oxidant- and metal-free.
Iodine-Mediated Sulfenylation of Imidazo[1,2- a ]pyridines with Ethyl Arylsulfinates
Sun, Jian,Mu, Yangxiu,Iqbal, Zafar,Hou, Jing,Yang, Minghua,Yang, Zhixiang,Tang, Dong
supporting information, p. 1014 - 1018 (2021/03/15)
A simple iodine-mediated approach is reported for the synthesis of sulfenylated imidazo[1,2- a ]pyridines through the reaction of imidazo[1,2- a ]pyridines with ethyl arylsulfinates under mild conditions. The reaction scope was investigated, and a plausible mechanism is proposed to elucidate the reaction process and activation mode. The results indicate that ethyl sulfinates are efficient sulfur sources for the construction of C-S bonds.
Solvent and catalyst-free synthesis of imidazo[1,2-a]pyridines by grindstone chemistry
Godugu, Kumar,Nallagondu, Chinna Gangi Reddy
, p. 250 - 259 (2020/10/23)
The present work describes the solvent and catalyst-free synthesis of imidazo[1,2-a]pyridines in excellent to nearly quantitative yields from 2-aminopyridines and a wide variety of ω-bromomethylketones using a grindstone procedure at 25°C to 30°C for 3 to
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.
Metal-free, Tf2NH-catalyzed 1, 6-conjugate addition of imidazopyridine to para-quinone methides: Easy access to C3-functionalized triarylmethane imidazopyridine
Khonde, Nilesh S.,Said, Madhukar S.,Sabane, Jagjivan K.,Gajbhiye, Jayant M.,Kumar, Pradeep
supporting information, (2021/10/30)
An inexpensive and commercially available Tf2NH-catalyzed 1,6-conjugate addition of imidazopyridine (IMPY) heterocycles to para-quinone methides (p-QMs) is reported. The present transformation provides a diverse class of C3-functionalized triarylmethanes heterocyclic derivatives of imidazopyridine. These metal-free transformations provided a very broad substrate scope of conjugate addition product with a high yield up to 97% within a short duration.
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.
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
, (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.
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.
PhI(OAc)2-mediated oxidative C[sbnd]H sulfoximination of imidazopyridines under mild conditions
Luan, Nannan,Liu, Zhenwei,Han, Shuaijun,Shen, Linhua,Li, Jingya,Zou, Dapeng,Wu, Yangjie,Wu, Yusheng
supporting information, (2019/11/26)
A facile protocol for direct oxidative C[sbnd]N bond coupling of unactivated imidazo[1,2-a]pyridines with NH-sulfoximines was disclosed using sulfoximines as the nitrogen sources in the presence of (diacetoxy)iodobenzene (PhI(OAc)2). The reacti
