- Iodine-catalyzed regioselective sulfenylation of imidazoheterocycles in PEG400
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An iodine-catalyzed sulfenylation of imidazo[1,2-a]-pyridines, -pyrimidines, and [1,2-b]pyridazines is herein described with various thiophenols using hydrogen peroxide as an oxidizing agent in PEG400. The method enabled the formation of 3-arylthioimidazoheterocycles in moderate to excellent yields under metal-free conditions. Several functional groups were well tolerated under our optimized conditions. This journal is
- Hiebel, Marie-Aude,Berteina-Raboin, Sabine
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- Electrochemical Oxidative C3 Acyloxylation of Imidazo[1,2- a]pyridines with Hydrogen Evolution
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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.
- Yuan, Yong,Zhou, Zhilin,Zhang, Lin,Li, Liang-Sen,Lei, Aiwen
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- One-pot synthesis of 2-phenylimidazo[1,2-α]pyridines from acetophenone, [Bmim]Br3 and 2-aminopyridine under solvent-free conditions
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One-pot synthesis of 2-phenylimidazo[1,2-α]pyridines from acetophenone, [Bmim]Br3 and 2-aminopyridine under solvent-free conditions in the presence of Na2CO3, gave the corresponding 2-phenylimidazo[1,2-α]pyridines in excel
- Le, Zhang-Gao,Xie, Zong-Bo,Xu, Jian-Ping
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- Iodine mediated oxidative cross coupling of 2-aminopyridine and aromatic terminal alkyne: A practical route to imidazo[1,2-: A] pyridine derivatives
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A novel, transition-metal free route leading to imidazo[1,2-a]pyridine derivatives via iodine mediated oxidative coupling between 2-aminopyridine and aromatic terminal alkyne has been demonstrated. This newly developed method discloses an operationally simple way for the construction of imidazoheterocycles. Commercially available antiulcer drug zolimidine may readily be synthesized employing this method.
- Samanta, Surya Kanta,Bera, Mrinal K.
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- Solvent- and catalyst-free synthesis of imidazo[1,2-a]pyridines under microwave irradiation
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A facile solvent- and catalyst-free method for the synthesis of a series of imidazo[1,2-a]pyridines in good to excellent yields by the condensation of 2-aminopyridines with α-bromoketones under microwave irradiation has been developed. The important featu
- Kong, Dulin,Wang, Xianghui,Shi, Zaifeng,Wu, Mingshu,Lin, Qiang,Wang, Xin
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- Oxidation Potential-Guided Electrochemical Radical-Radical Cross-Coupling Approaches to 3-Sulfonylated Imidazopyridines and Indolizines
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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.
- Kim, Wansoo,Kim, Hun Young,Oh, Kyungsoo
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- Copper-Catalyzed Aerobic Oxidative Cyclization of Ketoxime Acetates with Pyridines for the Synthesis of Imidazo[1,2-a]pyridines
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A copper(I)-catalyzed aerobic oxidative coupling of ketoxime acetates with simple pyridines for the synthesis of imidazo[1,2-a]pyridines has been developed. This reaction tolerates a wide range of functional groups and it affords a series of valuable imidazo[1,2-a]pyridines in high yields under mild conditions.
- Ren, Zhi-Hui,Zhao, Mi-Na,Yi, Yukun,Wang, Yao-Yu,Guan, Zheng-Hui
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- A copper-catalyzed multi-component reaction accessing fused imidazo-heterocycles via C-H functionalization
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An efficient synthesis of fused imidazo-heterocycles is described using Cu(OTf)2 in [bmim]BF4 by the multi-component reaction of pyridin-2(1H)-one or thiazol/benzo[d]thiazol-2(3H)-ones with O-tosylhydroxyl amine and acetophenones under microwave irradiation. The present method is very rapid and the product formation occurs via a C-H functionalization/tandem addition-cyclization process. The ionic liquid containing copper triflate is recovered and reused four times.
- Kumar, G. Santosh,Ragini, S. Pushpa,Kumar, A. Sanjeeva,Meshram
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- Iron-Catalyzed Dehydrogenative sp3-sp2 Coupling via Direct Oxidative C-H Activation of Acetonitrile
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An iron-catalyzed dehydrogenative sp3-sp2 coupling of acetonitrile and 2-arylimidazo[1,2-a]pyridine has been realized, which can serve as a novel approach toward heteroarylacetonitriles. The merit of this strategy is illustrated by the breadth of functional groups tolerated in the transformation and the fast access to pharmaceuticals (such as zolpidem) directly from the heteroarylacetonitriles.
- Su, Huimin,Wang, Luyao,Rao, Honghua,Xu, Hao
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- Electrochemical Oxidative C—H Sulfenylation of Imidazopyridines with Hydrogen Evolution
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Selective oxidative C—H sulfenylation of imidazopyridine heterocycles is achieved using an undivided electrolytic cell. The reaction avoids the use of stoichiometric amount of external chemical oxidant and produces hydrogen gas as the only byproduct. Both
- Yuan, Yong,Cao, Yangmin,Qiao, Jin,Lin, Yueping,Jiang, Xiaomei,Weng, Yaqing,Tang, Shan,Lei, Aiwen
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- Easy and efficient selenocyanation of imidazoheterocycles using triselenodicyanide
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The regioselective selenocyanation of imidazoheterocycles using triselenodicyanide at room temperature is reported. The electrophilic aromatic substitution of a broad range of substrates is promoted by the triselenodicyanide obtained by oxidative coupling
- Redon, Sébastien,Obah Kosso, Anne Roly,Broggi, Julie,Vanelle, Patrice
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- One-Pot Sequential Bromination and Fluorination to Access 3-Fluoroimidazo[1,2-a]pyridines from Arylketones
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3-Fluoro-2-arylimidazo[1,2-a]pyridines were selectively synthesised in one-pot from acetophenones and 2-aminopyridines under mild conditions. The sequence of reactions involved bromination, condensation, and late-stage fluorination. Two halogenating reagents play key roles in the process. We found that tetrabutylammonium tribromide and SelectfluorTM gave excellent yields of the desired products in the one-pot sequential reaction.
- Udavant, Rohini N.,Yadav, Ashok R.,Shinde, Sandip S.
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- Copper(I) iodide-catalysed aerobic oxidative synthesis of imidazo [1,2-α]pyridines from 2-aminopyridines and methyl ketones
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We report here an operationally simple copper-catalysed synthesis of imidazo [1,2-α]pyridines through C-H activation with oxidative linkage of two C-N bonds under very mild conditions using molecular oxygen as a sole oxidant. The process allows the quick assembly of imidazo [1,2-α]pyridines including the antiulcer drug zolimidine from inexpensive and readily available 2-aminopyridines and methyl ketones with broad range of functional group tolerance.
- Mohan, Darapaneni Chandra,Donthiri, Ramachandra Reddy,Rao, Sadu Nageswara,Adimurthy, Subbarayappa
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- Regioselective Oxidative C-H Phosphonation of Imidazo[1,2-a]pyridines and Related Heteroarenes Mediated by Manganese(III) Acetate
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Herein, we report a MnIII-mediated regioselective method for the direct C-H phosphonation of imidazo[1,2-a]pyridines by using dialkyl phosphites. 3-Phosphonated imidazo[1,2-a]pyridines are synthesized in good to excellent yields under the optimized reaction conditions. The present method is also applicable to the functionalization of related heteroarenes, and unlike previously reported methods, the present strategy works well with (NH)-heteroarenes. Regioselective synthesis of phosphonylated heteroarenes: A mild, direct, and regioselective C-H phosphonation of imidazo[1,2-a]pyridines and related heteroarenes has been developed. Unlike those previously reported, the present method also works with (NH)-heteroarenes.
- Yadav, Mahipal,Dara, Saidulu,Saikam, Varma,Kumar, Mukesh,Aithagani, Sravan Kumar,Paul, Satya,Vishwakarma, Ram A.,Singh, Parvinder Pal
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- Electrochemical oxidative selenylation of imidazo[1,2–a]pyridines with diselenides
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Electrochemical oxidative selenylation of imidazo[1,2–a]pyridines has been developed. The reaction proceeds in an undivided electrochemical cell equipped with glassy carbon electrodes employing LiClO4 as a supporting electrolyte. This approach
- Kim, Yeon Joo,Kim, Dae Young
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- Iodide-Catalyzed Phosphorothiolation of Heteroarenes Using P(O)H Compounds and Elemental Sulfur
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Organothiophosphates have found widespread application as biologically active compounds and synthetic intermediates in medicinal chemistry. The first transition-metal-free one-pot direct synthesis of heterocyclic phosphorothioates involving indole or imidazo[1,2-a]pyridine derivatives, elemental sulfur, and P(O)H compounds is presented. The use of NaI or KI as a catalyst, tert-butyl hydroperoxide as an oxidant, various indole and imidazo[1,2-a]pyridine derivatives are tolerant in this transformation, affording the corresponding products in good to excellent yields. Moreover, this method can be easily adapted to large-scale preparation. O,O-Diethyl S-(1-phenyl-1H-indol-3-yl) phosphorothioate presents potent anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW264.7 cells in a dose-dependent manner. (Figure presented.).
- Shi, Shanshan,Chen, Jun,Zhuo, Shaohua,Wu, Zi'ang,Fang, Meijuan,Tang, Guo,Zhao, Yufen
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- Multicomponent Synthesis of Imidazo[1,2- a]pyridines: Aerobic Oxidative Formation of C-N and C-S Bonds by Flavin-Iodine-Coupled Organocatalysis
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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.
- Okai, Hayaki,Tanimoto, Kazumasa,Ohkado, Ryoma,Iida, Hiroki
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- An efficient, catalyst- and solvent-free synthesis of imidazo[1,2-a] pyridines and 2,4-disubstituted thiazoles on grinding
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An efficient synthesis of imidazo[1,2-a]pyridines and 2,4-disubstituted thiazoles in excellent yield under catalyst-and solvent-free conditions at room temperature on grinding has been developed. The important features of this method are that it is reasonably fast, very clean, high yielding, simple workup and environmentally benign.
- Zhu, Dongjian,Chen, Jiuxi,Wu, Dengze,Liu, Miaochang,Ding, Jinchang,Wu, Huayue
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- A simple and efficient route to 2-arylimidazo[1,2-a]pyridines and zolimidine using automated grindstone chemistry
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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.
- Das, Dharmendra,Bhutia, Zigmee T.,Panjikar, Padmini C.,Chatterjee, Amrita,Banerjee, Mainak
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- Metal-Free Site-Specific Hydroxyalkylation of Imidazo[1,2- A[pyridines with Alcohols through Radical Reaction
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An effective approach to realize the direct hydroxyalkylation of imidazo[1,2-a]pyridines with alcohols promoted by di-tert-butyl peroxide was described without any metal catalyst. It is the first time that the dehydrogenative C(sp3)-C(sp2) coupling of imidazo[1,2-a]pyridines with alcohols occurred regioselectively at the C-5 position of imidazo[1,2-a]pyridines. Multisubstituted imidazopyridine derivatives were smoothly synthesized in moderate to good yields. Through a series of control experiments, a free-radical pathway was proposed to explain the experiment.
- Jin, Shengzhou,Xie, Bo,Lin, Sen,Min, Cong,Deng, Ruihong,Yan, Zhaohua
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- A multi pathway coupled domino strategy: I2/ TBHP-promoted synthesis of imidazopyridines and thiazoles via sp3, sp2 and sp C-H functionalization
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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.
- Feng, Lei,Li, Shichen,Ma, Chen,Wang, Xinfeng,Wang, Yishou,Yao, Yiming
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p. 5919 - 5927
(2022/03/31)
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- Synthesis and Structure?Activity Relationships of Imidazopyridine/Pyrimidine- and Furopyridine-Based Anti-infective Agents against Trypanosomiases
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Neglected tropical diseases remain among the most critical public health concerns in Africa and South America. The drug treatments for these diseases are limited, which invariably leads to fatal cases. Hence, there is an urgent need for new antitrypanosomal drugs. To address this issue, a large number of diverse heterocyclic compounds were prepared. Straightforward synthetic approaches tolerated pre-functionalized structures, giving rise to a structurally diverse set of analogs. We report on a set of 57 heterocyclic compounds with selective activity potential against kinetoplastid parasites. In general, 29 and 19 compounds of the total set could be defined as active against Trypanosoma cruzi and T. brucei brucei, respectively (antitrypanosomal activities 10 μM). The present work discusses the structure?activity relationships of new fused-ring scaffolds based on imidazopyridine/pyrimidine and furopyridine cores. This library of compounds shows significant potential for anti-trypanosomiases drug discovery.
- Silva, Daniel G.,Junker, Anna,de Melo, Shaiani M. G.,Fumagalli, Fernando,Gillespie, J. Robert,Molasky, Nora,Buckner, Frederick S.,Matheeussen, An,Caljon, Guy,Maes, Louis,Emery, Flavio S.
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supporting information
p. 966 - 975
(2020/12/04)
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- Metal-free oxidative decarbonylative halogenation of fused imidazoles
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An efficient strategy has been developed for the deformylative halogenation of carbaldehyde imidazo-fused heterocycles in the presence of TBHP controlled by temperature. A convenient and sequential functionalization (C8 to C3) portrays the synthetic utility of the current method.N-Heterocycle benzamide products were also observedviathe ring opening of imidazopyridines through the cleavage of C-C bond at high temperatures. Features of this method include temperature-controlled excellent regioselectivity, mild conditions and functional group tolerance.
- Kumar, Gulshan,Shankar, Ravi,Singh, Davinder,Tali, Javeed Ahmad
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supporting information
p. 20551 - 20555
(2021/11/23)
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- Unconventional Reactivity with DABCO-Bis(sulfur dioxide): C–H Bond Sulfenylation of Imidazopyridines
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This work highlights the unexpected and unprecedented outcome of the reactivity with DABCO-bis(sulfur dioxide). The use of this reagent led to the exclusive introduction of a sulfur atom on the C-3 position of imidazopyridines instead of a sulfone group.
- Le Bescont, Julie,Breton-Patient, Chloé,Piguel, Sandrine
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p. 2101 - 2109
(2020/04/07)
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- One-pot NBS-promoted synthesis of imidazoles and thiazoles from ethylarenes in water
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A facile and eco-friendly method has been developed for the synthesis of imidazoles and thiazoles from ethylarenes in water. The reaction proceeds via in situ formation of α-bromoketone using NBS as a bromine source as well as an oxidant, followed by trapping with suitable nucleophiles to provide the corresponding products in good yields under metal-free conditions.
- Chen, Liang,Zhu, Huajian,Wang, Jiang,Liu, Hong
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- Electrochemically initiated intermolecular C-N formation/cyclization of ketones with 2-aminopyridines: An efficient method for the synthesis of imidazo[1,2-: A] pyridines
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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.
- Feng, Mei-Lin,Li, Shu-Qi,He, Hui-Zi,Xi, Long-Yi,Chen, Shan-Yong,Yu, Xiao-Qi
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supporting information
p. 1619 - 1624
(2019/04/08)
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- Exogenous-oxidant-free electrochemical oxidative C-H phosphonylation with hydrogen evolution
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We herein report a versatile and environmentally friendly electrochemical oxidative C-H phosphonylation protocol. This protocol features a broad substrate scope; not only C(sp2)-H phosphonylation, but also C(sp3)-H phosphonylation is tolerated well under exogenous-oxidant-free and metal catalyst-free electrochemical oxidation conditions.
- Yuan, Yong,Qiao, Jin,Cao, Yangmin,Tang, Jingmei,Wang, Mengqin,Ke, Guojuan,Lu, Yichen,Liu, Xue,Lei, Aiwen
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supporting information
p. 4230 - 4233
(2019/04/30)
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- Rhodium(II)-Catalyzed Regioselective C3-Alkylation of 2-Arylimidazo[1,2-a]pyridines with Aryl Diazoesters
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A regioselective C3-alkylation based on the reaction of 2-arylimidazo[1,2-a]pyridines with a wide range of aryl α-diazoesters in the presence of a Rh(II) catalyst in dichloroethane at room temperature was developed. This method could be applied in the synthesis of benzoimidazoquinolizinone and cycloheptaimidazopyridinone, which are novel heterocyclic scaffolds. (Figure presented.).
- Kim, Hyunseok,Byeon, Minhyeon,Jeong, Eunchong,Baek, Yonghyeon,Jeong, Seung Jin,Um, Kyusik,Han, Sang Hoon,Han, Gi Uk,Ko, Gi Hoon,Maeng, Chanyoung,Son, Jeong-Yu,Kim, Dongwook,Kim, Sung Hong,Lee, Kooyeon,Lee, Phil Ho
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supporting information
p. 2094 - 2106
(2019/03/21)
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- Electrochemical oxidative C-H/N-H cross-coupling for C-N bond formation with hydrogen evolution
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Under metal catalyst-free and exogenous-oxidant-free conditions, a series of C-3 aminated imidazo[1,2-a]pyridines were synthesized by electrochemical intermolecular oxidative C-H/N-H cross-coupling. Furthermore, by using a catalytic amount of ferrocene as
- Yu, Yi,Yuan, Yong,Liu, Huilin,He, Min,Yang, Mingzhu,Liu, Pan,Yu, Banying,Dong, Xuanchi,Lei, Aiwen
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supporting information
p. 1809 - 1812
(2019/02/12)
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- Formation of Methylene Linkage for N-Heterocycles: Sequential C-H and C-O Bond Functionalization of Methanol with Cosolvent Water
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An iron-catalyzed methylene forming strategy is disclosed through sequential C-H and C-O bond functionalization of methanol with cosolvent water. This protocol provides an easy and novel access to methylene-tethered imidazo[1,2-a]pyridine and 2-aminopyridine analogues in a sustainable manner and represents a complementary approach to traditional methylene forming strategies.
- Li, Na,Bai, Jinku,Zheng, Xiaolin,Rao, Honghua
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p. 6928 - 6939
(2019/06/14)
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- Method for synthesizing 2-arylimidazo[1, 2-a]pyridine compounds from ethylbenzene compounds
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The invention discloses a method for synthesizing 2-arylimidazo[1, 2-a]pyridine compounds from ethylbenzene compounds and belongs to the field of 2-arylimidazo[1, 2-a]pyridine derivative synthesis. The method comprises that an ethylbenzene compound, a phase transfer catalyst, N-bromosuccinimide NBS and AIBN are added into water, the solution undergoes a reaction at 60 DEG C, an inorganic base andan alpha-aminopyridine compound are added into the reaction product, and the mixture undergoes a reaction at 80 DEG C to produce the 2-arylimidazo[1, 2-a]pyridine compound. The method creatively utilizes the ethylbenzene compound to synthesize the 2-arylimidazo[1, 2-a]pyridine compound. Compared with the 2-bromoacetophenone commonly used as a 2-arylimidazo[1, 2-a]pyridine compound synthesis raw material in the industry, the ethylbenzene compound is cheaper and more easily available.
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Paragraph 0025; 0026; 0027; 0028
(2018/11/27)
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- Method for synthesizing 2-arylimidazo[1, 2-a]pyridine compound
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The invention discloses a method for synthesizing a 2-arylimidazo[1, 2-a]pyridine compound and belongs to the technical field of organic synthesis. The method comprises that an ethylbenzene compound,dibromohydantoin DBH and t-butyl hydroperoxide TBHP are added into water and undergo a reaction at 60 DEG C, an inorganic base and an alpha-aminopyridine compound are added into the reaction product and the mixture undergoes a reaction at 80 DEG C to produce a desired product 2-arylimidazo[1, 2-a]pyridine compound. The 2-arylimidazo[1, 2-a]pyridine compound is synthesized from the ethylbenzene compound which is cheaper and more readily available than the 2-arylimidazo[1, 2-a]pyridine compounds such as 2-bromoacetophenone commonly used in the industry.
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Paragraph 0023; 0024; 0025; 0026
(2018/11/27)
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- Au-catalyzed domino process synthesis of imidazo[1,2-a]pyridines from 2-aminopyridine and N-tosylhydrazones: An efficient C[sbnd]N bond formation reaction
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A novel Au-catalyzed domino reaction for the synthesis of imidazo[1,2-a]pyridines from 2-aminopyridine and N-tosylhydrazones has been developed using molecular oxygen. It represents a new strategy for the formation of C[sbnd]N bonds. This transformation demonstrated a broad tolerance toward the substrates and allowed the generation of a diverse imidazo[1,2-a]pyridine derivatives with good yields.
- Guo, Pengfeng,Huang, Shuyu,Mo, Jiaxian,Chen, Xiaoyan,Jiang, Hangqi,Chen, Weifeng,Cai, Hehuan,Zhan, Haiying
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- One-Pot Three-Component Synthesis of Alkylthio-/Arylthio- Substituted Imidazo[1,2-a]pyridine Derivatives via C(sp2)–H Functionalization
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Sulfenylation is an important transformation to generate C?S bonds in organic synthesis. Here, two three-component synthetic protocols have been developed by using imidazo[1,2-a]pyridine, inorganic, odorless S8 and alcohols or arylboronic acids
- Zhu, Wenhui,Ding, Yingcai,Bian, Zhaogang,Xie, Ping,Xu, Baojun,Tang, Qiujie,Wu, Wei,Zhou, Aihua
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supporting information
p. 2215 - 2221
(2017/07/07)
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- One pot synthesis of substituted imidazopyridines and thiazoles from styrenes in water assisted by NBS
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Heating of commercially available styrenes with NBS in water followed by reaction with 2-aminopyridines or thioamides afforded important heterocyclic scaffolds in a one pot procedure. The reaction proceeds via co-oxidant free, in situ formation of α-bromoketone using NBS as a bromine source as well as an oxidant followed by trapping with suitable nucleophiles to provide imidazopyridines and thiazoles.
- Shinde, Mahesh H.,Kshirsagar, Umesh A.
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p. 1455 - 1458
(2016/04/04)
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- The flocculated acryloyldimethyltauric molecule ligand
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Provided are certain benzothiazole, imidazothiazole, imidazopyrimidine and imidazopyridine compounds, including, for example: formula (I) and pharmaceutically and physiologically acceptable salts, hydrates, and solvates thereof. Such compounds can be used as diagnostic ligands or labels of tau protein and PHF.
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Paragraph 0703; 0704
(2016/10/08)
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- Straightforward synthesis of various 2,3-diarylimidazo[1,2-a]pyridines in peg400 medium through one-pot condensation and C-H arylation
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PEG400 is described herein as a suitable medium for the condensation of various 2-amino pyridines with α-bromo ketones. 2-Arylimidazo[1,2-a]pyridines were synthetized in a short time through microwave irradiation in moderate to excellent yields
- Hiebel, Marie-Aude,Fall, Yacoub,Scherrmann, Marie-Christine,Berteina-Raboin, Sabine
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p. 4643 - 4650
(2014/08/05)
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- Copper-catalyzed aerobic oxidative C-H functionalization of substituted pyridines: Synthesis of imidazopyridine derivatives
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A novel, efficient, and practical method for the synthesis of imidazopyridine derivatives has been developed through the copper-catalyzed aerobic oxidative C-H functionalization of substituted pyridines with N-(alkylidene)-4H-1,2,4-triazol-4-amines. The procedure occurs by cleavage of the N-N bond in the N-(alkylidene)-4H-1,2,4-triazol-4-amines and activation of an aryl C-H bond in the substituted pyridines. This is the first example of the preparation of imidazopyridine derivatives by using pyridines as the substrates by transition-metal-catalyzed C-H functionalization. This method should provide a novel and efficient strategy for the synthesis of other nitrogen heterocycles.
- Yu, Jipan,Jin, Yunhe,Zhang, Hao,Yang, Xiaobo,Fu, Hua
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supporting information
p. 16804 - 16808
(2014/01/06)
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- Copper(I) iodide/boron trifluoride etherate-cocatalyzed aerobic dehydrogenative reactions applied in the synthesis of substituted heteroaromatic imidazo[1,2-a]pyridines
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Compared with the well-known palladium-catalyzed oxidative dehydrogenation coupling reactions, similar transforms initiated by copper/oxygen have attracted more and more attention. We have investigated a novel construction of heteroaromatic imidazo[1,2-a]
- Cai, Zhong-Jian,Wang, Shun-Yi,Ji, Shun-Jun
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supporting information
p. 2686 - 2692
(2013/10/21)
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- Heteroaromatic imidazo[1,2-a]pyridines synthesis from C-H/N-H oxidative cross-coupling/cyclization
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A novel silver-mediated highly selective C-H/N-H oxidative cross-coupling/cyclization between 2-aminopyridines and terminal alkynes has been demonstrated. This approach provided a simple way to construct heteroaromatic imidazo[1,2-a]pyridines. By using this protocol, the marketed drug zolimidine (antiulcer) could be synthesized easily.
- He, Chuan,Hao, Jing,Xu, Huan,Mo, Yiping,Liu, Huiying,Han, Juanjuan,Lei, Aiwen
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supporting information
p. 11073 - 11075,3
(2012/12/12)
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- Heteroaromatic imidazo[1,2-a]pyridines synthesis from C-H/N-H oxidative cross-coupling/cyclization
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A novel silver-mediated highly selective C-H/N-H oxidative cross-coupling/cyclization between 2-aminopyridines and terminal alkynes has been demonstrated. This approach provided a simple way to construct heteroaromatic imidazo[1,2-a]pyridines. By using this protocol, the marketed drug zolimidine (antiulcer) could be synthesized easily.
- He, Chuan,Hao, Jing,Xu, Huan,Mo, Yiping,Liu, Huiying,Han, Juanjuan,Lei, Aiwen
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supporting information
p. 11073 - 11075
(2013/01/15)
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- Synthesis of bridgehead nitrogen heterocycles on a solid surface
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Bridgehead nitrogen heterocycles were synthesized from heteroaromatic amidines and cyclic or acyclic α-bromoketones under solvent-free conditions at room temperature on a solid surface in excellent yields, which are higher than those obtained with hithert
- Ponnala, Shashikanth,Kumar, S. T. V. S. Kiran,Bhat, Bashir A.,Sahu, Devi Prasad
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p. 901 - 906
(2007/10/03)
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