- Synthesis of 2-aminoindolizines by 1,3-dipolar cycloaddition of pyridinium ylides with electron-deficient ynamides
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Electron-deficient ynamides, possessing an ynoate or an ynone moiety, have been successfully involved for the first time in a 1,3-dipolar cycloaddition with stabilized pyridinium ylides. These reactions afford an efficient and general access toward a variety of substituted 2-aminoindolizines which can serve as useful precursors for the synthesis of other more complex nitrogen heterocycles.
- Brioche, Julien,Meyer, Christophe,Cossy, Janine
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- Ultrasound-promoted regioselective synthesis of chalcogeno-indolizines by a stepwise 1,3-dipolar cycloaddition
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A series of new organochalcogen derivatives of indolizines was synthesized in moderate to excellent yields from pyridinium salts and chalcogeno-alkynes. The reaction can be carried out under thermal conditions or by sonochemical processes in short reaction times. The stepwise cycloaddition reaction forming chalcogeno-indolizines is regioselective and extends to a broad range of functional groups. Furthermore, novel chalcogeno-alkynes are reported and the first derivatives of teluro-indolizine are described. The influence of selenium functionalization on the photophysical properties of indolizines is also described, in which the compounds showed absorption in the UV–Vis region around 360 nm and emission in the blue-to-green region. Relatively low fluorescence quantum yield (?fl) values were calculated, in agreement with the chalcogen effect on other heterocycles.
- Vieira, Marcelo M.,Dalberto, Bianca T.,Coelho, Felipe L.,Schneider, Paulo H.
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- Synthesis of tetrasubstituted pyridazines via cascade reactions of diazocarbonyl compounds with pyridinium ylides
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Reactions of pyridinium ylides with diazocarbonyl compounds involve the formation of functionalized azine intermediates that can undergo intramolecular cyclocondensation into tetrasubstituted pyridazines provided the starting reagents contain carbonyl groups. Reactions of pyridinium ylides with diazo compounds were studied for various substituents in both the substrates.
- Tomilov,Platonov,Dorokhov,Zhalnina
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- Preparation of 1-trifluoroacetyl indolizines and their derivatives via the cycloaddition of pyridinium N-ylides with 4-4-ethoxy1-1,1,1-trifluorobut-3-en-one
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Under basic reaction conditions pyridinium or isoquinolinium N-ylides (C5H5N+ CH2YBr- or C9H7N+CH2YBr-, Y : CO2R, CN, PhCO) reacted readily with 4-ethoxyl-1,1,1-trifluorobut-3-en-2-one to give the corresponding 1-trifluoroacetyl substituted indolizines or pyrrolo-[1,2-a]isoquinolines. The molecular structure of 1-trifluoromethyl-3-methoxyl-pyrrolo-[1,2-a]isoquinoline is presented.
- Zhu, Shi-Zheng,Qin, Chao-Yue,Wang, Yan-Li,Chu, Qian-Li
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- Stereoselective Cycloaddition of Pyridinium or Isoquinolinium Methylides with Olefinic Dipolarophiles and Subsequent Cycloadditions of the Cycloadducts with Nitrile Oxides
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Pyridinium or isoquinolinium methylides undergo highly stereo- and regioselective cycloadditions with olefinic dipolarophiles to form unstable tetrahydroindolizine derivatives.One of the two double bonds existing in the dihydro heteroaromatic ring of the cycloadducts reacts with nitrile oxides, in the same flask, in stereo-, regio-, and periselective fashions to lead to stable isoxazole-fused tetrahydroindolizines in good yields.
- Tsuge, Otohiko,Kanemasa, Shuji,Takenaka, Shigeori
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- An efficient microwave accelerated three component reaction of phenacyl azides and pyridinium phenacyl salts: A facile greener approach to 2-amino-2-ene-1,4-diones/pyrrolidin-2-ones
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A mild and efficient base promoted, microwave assisted, green synthesis of 2-amino-2-ene-1,4-diones has been described by the decomposition of phenacyl azides followed by treatment with pyridinium salts of phenacyl bromides in aqueous media. A diverse range of substrates bearing electron-releasing and electron-withdrawing substituents were well tolerated and delivered corresponding 2-amino-2-ene-1,4-diones in good yields. Synthesized 2-amino-2-ene-1,4-diones have been further explored in the synthesis of various substituted 4-hydroxypyrrolidin-2-ones.
- Chimaladenne, Venkateswarlu,Manda, Ramesh,Gudipally, Ashok Reddy,Valluru, Krishna Reddy,Brahman, Pradeep Kumar,Somarapu, Vijaya Laxmi
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- Benzoquinoline-based fluoranthene derivatives as electron transport materials for solution-processed red phosphorescent organic light-emitting diodes
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A new electron transport material (ETM) with two fluoranthene and a benzoquinoline moiety was synthesized for the fabrication of solution-processed phosphorescent organic light-emitting diodes (PHOLEDs). In particular, we designed a bulky structure with a large twisted angle and improved thermal stability as compared to those of the common ETMs [e.g., 2,2′,2′′-(1,3,5-phenylene)tris(1-phenyl-1H-benzimidazole) (TPBI)] for device stability. As a result, we found that 4-(3-(fluoranthen-3-yl)-5-(fluoranthen-4-yl)phenyl)-2-phenyl-benzo[h]quinoline (FRT-PBQ) showed high glass transition temperature (Tg: ~184 °C) and moderately high electron transport behavior despite its bulky structural moieties. Moreover, we fabricated solution-processed red PHOLEDs with FRT-PBQ, and a relatively high current efficiency and external quantum efficiency of up to 20.7 cd A-1 and 15.5%, respectively, were achieved. In addition, the device lifetime was extended by a factor of 1.7 as compared to that of the device fabricated with TPBI as a common ETM.
- Park, So-Ra,Shin, Dong Heon,Park, Sang-Mi,Suh, Min Chul
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- Regioisomeric synthesis of dihydrofuro[2,3-d]pyrimidines in a diastereoselective manner involving nitrogen ylides in one-pot three-component reaction
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Synthesized some novel regioisomers of furo[2,3-d]pyrimidines in a diastereoselective manner via one-pot three-component reaction of barbituric acids, aryl aldehydes and pyridinium bromides in the presence of triethylamine as base. Both the isomers were obtained in comparable ratio with excellent overall yield.
- Dutta, Leema,Sharma, Meenakshi,Bhuyan, Pulak J.
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- Synthesis and characterisation of extended π-bonding systems in cycloimmonium ylides derived from the 4,4′-bipyridine
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Disubstituted cycloimmonium ylides derived from the 4,4'-bipyridine with one, two or four ylidic systems in their molecular structure are described as stable compounds. Synthesis of some bridged 1,1'-disubstituted 4,4'-bipyridinium dimethylides in which 1,4- or 1,3-phenylene spacers may be used, provide some new macromolecular cycloimmonium ylides with spatially extended π-bonding system. These compounds were obtained by the chemical conversion of 4,4'-bipyridinium salts as viologens or bis-viologens, with acylating or carbamoylating agents, in basic media. The characterisation of all compounds has been mainly performed by 1H and 13C NMR spectroscopy.
- Depature, Ludovic,Surpateanu, Gheorghe
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- Three-component synthesis of novel spirooxindole–furan derivatives using pyridinium salts
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A simple and efficient synthesis of novel spirooxindole–furan derivatives has been investigated by a modified version of the“interrupted” Feist–Bénary (IFB) reaction of isatin derivatives, 1,3-dicarbonyl compounds and N-phenacyl pyridinium salts in the presence of triethylamine. The reaction has been carried out under mild conditions in ethanol, and the products were obtained in good to moderate yields with a simple work-up procedure.
- Baharfar, Robabeh,Asghari, Sakineh,Zaheri, Farya,Shariati, Narges
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- Computer-aided molecular design of solvents for accelerated reaction kinetics
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Solvents can significantly alter the rates and selectivity of liquid-phase organic reactions, often hindering the development of new synthetic routes or, if chosen wisely, facilitating routes by improving rates and selectivities. To address this challenge, a systematic methodology is proposed that quickly identifies improved reaction solvents by combining quantum mechanical computations of the reaction rate constant in a few solvents with a computer-aided molecular design (CAMD) procedure. The approach allows the identification of a high-performance solvent within a very large set of possible molecules. The validity of our CAMD approach is demonstrated through application to a classical nucleophilic substitution reaction for the study of solvent effects, the Menschutkin reaction. The results were validated successfully by in situ kinetic experiments. A space of 1,341 solvents was explored in silico, but required quantum-mechanical calculations of the rate constant in only nine solvents, and uncovered a solvent that increases the rate constant by 40%.
- Struebing, Heiko,Ganase, Zara,Karamertzanis, Panagiotis G.,Siougkrou, Eirini,Haycock, Peter,Piccione, Patrick M.,Armstrong, Alan,Galindo, Amparo,Adjiman, Claire S.
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- Silver-Promoted (4 + 1) Annulation of Isocyanoacetates with Alkylpyridinium Salts: Divergent Regioselective Synthesis of 1,2-Disubstituted Indolizines
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An unprecedented silver-promoted regioselective (4 + 1) annulation of isocyanoacetates with pyridinium salts is reported. The established protocol provides controlled, facile, and modular access to a range of synthetically useful N-fused heterocyclic scaffolds containing indolizines, pyrrolo[1,2-a]quinolines, pyrrolo[2,1-a]isoquinolines, and 1H-imidazo[4,5-a]indolizin-2(3H)-ones. A mechanistic pathway involving nucleophilic addition/protonation/elimination/cycloisomerization is proposed.
- Chen, Yan,Shatskiy, Andrey,Liu, Jian-Quan,K?rk?s, Markus D.,Wang, Xiang-Shan
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supporting information
p. 7555 - 7560
(2021/10/02)
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- Diversified Transformations of Tetrahydroindolizines to Construct Chiral 3-Arylindolizines and Dicarbofunctionalized 1,5-Diketones
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Enantioselective diverse synthesis of a small-molecule collection with structural and functional similarities or differences in an efficient manner is an appealing but formidable challenge. Asymmetric preparation and branching transformations of tetrahydroindolizines in succession present a useful approach to the construction of N-heterocycle-containing scaffolds with functional group, and stereochemical diversity. Herein, we report a breakthrough toward this end via an initial diastereo- A nd enantioselective [3 + 2] cycloaddition between pyridinium ylides and enones, following diversified sequential transformations. Chiral N,N′-dioxide-earth metal complexes enable the generation of optically active tetrahydroindolizines in situ, across the strong background reaction for racemate-formation. In connection with deliberate sequential transformations, involving convenient rearomatic oxidation, and light-active aza-Norrish II rearrangement, the tetrahydroindolizine intermediates were converted into the final library including 3-arylindolizine derivatives and dicarbofunctionalized 1,5-dicarbonyl compounds. More importantly, the stereochemistry of four-stereogenic centered tetrahydroindolizine intermediates could be efficiently transferred into axial chirality in 3-arylindolizines and vicinal pyridyl and aryl substituted 1,5-diketones. In addition, densely functionalized cyclopropanes and bridged cyclic compounds were also discovered depending on the nature of the pyridinium ylides. Mechanism studies were involved to explain the stereochemistry during the reaction processes.
- Feng, Xiaoming,He, Qianwen,Liu, Xiaohua,Pan, Chenjing,Su, Zhishan,Wu, Zhikun,Zhang, Dong,Zhou, Yuqiao
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supporting information
p. 15975 - 15985
(2020/10/18)
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- Indolizine derivative and preparation method thereof
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The invention discloses an indolizine derivative and a preparation method thereof. The indolizine derivative is prepared from pyridinium bromide and allenic acid ester through [3+2] cycloaddition reaction in a reaction solvent under the action of an inorganic base catalyst and a Lewis base promoter in a nitrogen atmosphere. The reaction substrate of the preparation method is simple, easy to synthesize and low in price; wherein the [3+2] cycloaddition reaction has the advantages of mild reaction conditions, high reaction efficiency, high indolizine derivative yield and high atom economy. Therefore, the indolizine derivative has the advantages of no catalyst residue, high purity and high application value.
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Paragraph 0060-0064; 0072-0075; 0081-0084
(2020/11/23)
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- Base-mediated 1,3-dipolar cycloaddition of pyridinium bromides with bromoallyl sulfones: a facile access to indolizine scaffolds
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An expedient and transition-metal-free synthetic strategy has been developed for the construction of substituted indolizines from a unique combination of pyridinium salts and 2-bromoallyl sulfones. This approach does not compromise with the diverse substitutions on both the pyridinium salts and 2-bromoallyl sulfones. Wide substrate scope, operational simplicity, milder reaction conditions and good to moderate yields are the merits associated with the current approach. Moreover, this method provides two products which are amenable for the generation of a library of key indolizine building blocks. This journal is
- Ganga Reddy, Velma,Hari Krishna, Namballa,Jadala, Chetna,Kamal, Ahmed,Shankaraiah, Nagula
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p. 8694 - 8701
(2020/11/17)
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- DMAP-Catalyzed Annulation Approach for Modular Assembly of Furan-Fused Chromenes
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With a tandem DMAP-catalyzed reaction between o-AQM, in which it is generated in situ from propargylic amine, and acyl carbene surrogate (from pyridinium ylide), a variety of polyarylated chromenes are assembled in good yields. This process does not require transition-metal catalyst and exhibits easy manipulation of the arene group and good functional group compatibility, particularly the -Br group which can be further transformed to other functionalities by cross-coupling reactions. The modular feature of o-AQM substrates and the simple operation procedures add further advantages to this synthetic method.
- He, Xinwei,Li, Ruxue,Choy, Pui Ying,Liu, Tianyi,Wang, Junya,Yuen, On Ying,Leung, Man Pan,Shang, Yongjia,Kwong, Fuk Yee
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supporting information
p. 9444 - 9449
(2020/12/21)
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- A metal-free approach for the synthesis of amides/esters with pyridinium salts of phenacyl bromides via oxidative C–C bond cleavage
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An efficient, simple, and metal-free synthetic approach for the N- and O-benzoylation of various amines/benzyl alcohols with pyridinium salts of phenacyl bromides is demonstrated to generate the corresponding amides and esters. This protocol facilitates the oxidative cleavage of a C–C bond followed by formation of a new C–N/C–O bond in the presence of K2CO3. Various pyridinium salts of phenacyl bromides can be readily transformed into a variety of amides and esters which is an alternative method for the conventional amidation and esterification in organic synthesis. High functional group tolerance, broad substrate scope and operational simplicity are the prominent advantages of the current protocol.
- Manasa, Kesari Lakshmi,Tangella, Yellaiah,Krishna, Namballa Hari,Alvala, Mallika
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supporting information
p. 1864 - 1871
(2019/08/12)
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- Unexpected reactivity of pyridinium salts toward alkynyl Fischer complexes to produce oxo-heterocycles
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The unprecedented reaction of ketone-containing aromatic pyridinium salts 3a-e and alkynyl Fischer complexes 1a-f proceeds via a mild domino process to provide 4,6-disubstituted pyran-2-ones 5a-k and 2,3,5-trisubstituted furans 6a-h (45-97%). According of the results of isotopic labeling experiments, a mechanism involving an initial Michael addition appears to be the key step, obtaining a mesomeric structure responsible for the formation of both products.
- Flores-Conde, María Inés,de la Cruz, Fabiola N.,López, Julio,Jiménez-Halla, J. óscar C.,Pe?a-Cabrera, Eduardo,Flores-álamo, Marcos,Delgado, Francisco,Vázquez, Miguel A.
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- Method of preparing 4,5-disubstituted 1,2,3-triazole with pyridinium salt
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The invention relates to a method of synthesizing a 4,5-disubstituted 1,2,3-triazole compound. The method comprises the following step of by taking pyridine, halohydrocarbon, sulfonic ester, aldehydeand sodium azide as raw materials, and performing room-temperature reaction with a one-pot method. The synthetic method does not need a metal-containing catalyst, has the advantages of high yield of synthetic products, mild reaction condition, good functional group compatibility and the like, is simple in operation step, mild in reaction condition and wide in application range of a substrate, hasinnovativeness and a potential practical value and is suitable for industrial production.
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Paragraph 0037-0038
(2018/09/08)
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- Facile one-pot tandem synthesis of perfluoroalkylated indolizines under metal-free mild conditions
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A direct metal-free method for the synthesis of perfluoroalkylated indolizines by means of DIPEA-promoted tandem C[sbnd]N/C[sbnd]C bond formation was developed. Various substituted pyridines and bromoacetyl derivatives with methyl perfluoroalk-2-ynoates proceeded smoothly in this mild transformation, and the desired products were obtained in good to excellent yields under air.
- He, Dong,Xu, Yuhong,Han, Jing,Deng, Hongmei,Shao, Min,Chen, Jie,Zhang, Hui,Cao, Weiguo
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p. 938 - 944
(2017/01/25)
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- DABCO-catalyzed multi-component domino reactions for the one-pot efficient synthesis of diverse and densely functionalized benzofurans in water
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An efficient, three-component strategy for the improved synthesis of a pharmaceutically interesting diverse kind of multi-functionalized benzofurans via one-pot two-step domino protocol with high diastereoselectivity in excellent yields has been established. The synthesis was achieved by reacting phenacyl bromides, N-heterocycles, aromatic aldehydes, and cyclic 1,3-dicarbonyl compounds in the presence of a catalytic amount of DABCO (1,4-diazabicyclo[2.2.2]octane) as an inexpensive, impressive, and readily available catalyst in water under reflux. In this process in total three new bonds (two C–C and one C–O) form in one pot. Short reaction time, excellent yields, no chromatographic purification, and evasion of environmentally hazardous or toxic catalysts and organic solvents in the entire reaction process may make this protocol very useful for academia and industry.
- Golchin, Sajedeh,Mosslemin, Mohammad Hossein,Yazdani-Elah-Abadi, Afshin,Shams, Nasim
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p. 1735 - 1749
(2017/02/15)
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- Preparation method of N-phenacylpyridinium bromide
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The invention relates to a preparation method of N-phenacylpyridinium bromide. The preparation method comprises the following steps: dissolving acetophenone into a certain solvent, and enabling the acetophenone and liquid bromine to react at the temperature of -20 DEG C to 40 DEG C according to a certain ratio, wherein reacting is performed for 2 to 8 hours to prepare 2-bromoacetophenone; in a certain solvent, enabling the 2-bromoacetophenone and pyridine to react at the temperature of 0 to 80 DEG C according to a certain ratio for 3 to 15 hours; after reacting, cooling to room temperature; extracting with ethyl acetate, washing with water and saturated salt water, drying with anhydrous sodium sulfate, and carrying out rotary evaporation and concentration to obtain an N-phenacylpyridinium bromide crude product; recrystallizing the crude product to obtain a pure product. The preparation method has the advantages that the raw materials are relatively easy to obtain and have a reasonable price; reaction conditions are moderate and the preparation method is easy to operate and easy to control; the post-treatment is simple; the product has stable quality and high purity.
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Paragraph 0010; 0011; 0012; 0013
(2017/08/29)
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- Novel 9H-indeno[2,1-b]pyridine compound and organic electroluminescent device comprising the same
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The present invention relates to a novel 9H-indeno[2,1-b]pyridine compound, and an organic light-emitting device including the same. According to the present invention, the organic light-emitting device which includes the 9H-indeno[2,1-b]pyridine compound in an electron transfer layer as an electron transfer material is excellent in light-emitting properties owing to enhanced electron transferability, induced an increase in power efficiency by improving driving voltage, and also ensures long lifespan and favorable power consumption.(AA) Comparative example 1(BB) Example 4(CC) Example 5(DD) Example 6COPYRIGHT KIPO 2017
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Paragraph 0096-0097
(2018/03/13)
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- NEW HOST MATERIAL AND ORGANIC ELECTROLUMINESCENT DEVICE USING THE SAME
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The present invention relates to a novel luminous host material and an organic electroluminescent device using the same. The organic electroluminescent device has excellent luminous characteristics and improves power consumption by enhancing driving voltage and inducing an increase in electrical power efficiency. The novel host material of the present invention is represented by chemical formula 1.COPYRIGHT KIPO 2016
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Paragraph 0176; 0182-0184
(2016/10/09)
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- Transition-Metal-Free Synthesis of Indolizines from Electron-Deficient Alkenes via One-Pot Reaction Using TEMPO as an Oxidant
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A one-pot method for the synthesis of multisubstituted indolizines from α-halo carbonyl compounds, pyridines, and electron-deficient alkenes is reported. The oxidative dehydrogenation reaction takes place under transition-metal-free conditions using TEMPO as an oxidant. This protocol uses ready available starting materials in a convenient procedure under mild reaction conditions.
- Shi, Fei,Zhang, Yu,Lu, Zhaole,Zhu, Xiaolei,Kan, Weiqiu,Wang, Xiang,Hu, Huayou
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p. 413 - 420
(2016/01/28)
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- Synthesis and biological activities of indolizine derivatives as alpha-7 nAChR agonists
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Human α7 nicotinic acetylcholine receptor (nAChR) is a promising therapeutic target for the treatment of schizophrenia accompanied with cognitive impairment. Herein, we report the synthesis and agonistic activities of a series of indolizine derivatives targeting to α7 nAChR. The results show that all synthesized compounds have affinity to α7 nAChR and some give strong agonistic activity, particularly most active agonists show higher potency than control EVP-6124. The docking and structure-activity relationship studies provide insights to develop more potent novel α7 nAChR agonists.
- Xue, Yu,Tang, Jingshu,Ma, Xiaozhuo,Li, Qing,Xie, Bingxue,Hao, Yuchen,Jin, Hongwei,Wang, Kewei,Zhang, Guisen,Zhang, Liangren,Zhang, Lihe
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- Synthesis of novel 2-aryl-3-benzoyl-1H-benzo[f]indole-4,9-diones using a domino reaction
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A convenient one-pot multicomponent synthetic approach was developed for the synthesis of novel 2-aryl-3-benzoyl-1H-benzo[f]indole-4,9-diones using 2-amino-1,4-naphthoquinone, N-acylmethylpyridinium bromides, and a variety of aromatic aldehydes.
- Nguyen, Trung Quang,Le Nhat, Thuy Giang,Vu Ngoc, Doan,Dang Thi, Tuyet Anh,Nguyen, Ha Thanh,Hoang Thi, Phuong,Nguyen, Hung Huy,Cao, Hai Thuong,Abbaspour Tehrani, Kourosch,Nguyen, Tuyen Van
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p. 4352 - 4355
(2016/09/13)
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- Selective hydrolysis of 1-cyanocyclopropane-1-carboxylates: Concise preparation of 1-carbamoylcyclopropane-1-carboxylates
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An efficient and straightforward method has been developed for the preparation of 1-carbamoylcyclopropane-1-carboxylate derivatives selective hydrolysis of 1-cyanocyclopropane-1-carboxylates by using hydroxylamine and sodium acetate system strategy. The of 1-carbamoylcyclopropane-1-carboxylate 2a was further confirmed by X-ray single crystal analysis.
- Liu, Jiaming,Zhang, Feixiang,Wang, Ting,Qing, Xushun,Wang, Cunde
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p. 694 - 697
(2016/11/18)
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- Highly Fluorinated Ir(III)-2,2′:6′,2″-Terpyridine-Phenylpyridine-X Complexes via Selective C-F Activation: Robust Photocatalysts for Solar Fuel Generation and Photoredox Catalysis
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A series of fluorinated Ir(III)-terpyridine-phenylpyridine-X (X = anionic monodentate ligand) complexes were synthesized by selective C-F activation, whereby perfluorinated phenylpyridines were readily complexed. The combination of fluorinated phenylpyridine ligands with an electron-rich tri-tert-butyl terpyridine ligand generates a "push-pull" force on the electrons upon excitation, imparting significant enhancements to the stability, electrochemical, and photophysical properties of the complexes. Application of the complexes as photosensitizers for photocatalytic generation of hydrogen from water and as redox photocatalysts for decarboxylative fluorination of several carboxylic acids showcases the performance of the complexes in highly coordinating solvents, in some cases exceeding that of the leading photosensitizers. Changes in the photophysical properties and the nature of the excited states are observed as the compounds increase in fluorination as well as upon exchange of the ancillary chloride ligand to a cyanide. These changes in the excited states have been corroborated using density functional theory modeling.
- Porras, Jonathan A.,Mills, Isaac N.,Transue, Wesley J.,Bernhard, Stefan
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supporting information
p. 9460 - 9472
(2016/08/12)
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- Synthesis and pH-dependent spectroscopic behavior of 2,4,6-trisubstituted pyridine derivatives
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Seven 2,4,6-trisubstituted pyridine derivatives with N,N-diethylaniline substituents at the 4-position were synthesized, and their spectroscopic properties in the absence and presence of acid were studied. The spectral effects of protonation, molar absorptivities, pKa values, and the structural origins of the observed spectral behavior were ascertained. The pyridine nitrogen was found to be more basic than the diethylamino nitrogen atom. Protonation of the pyridine ring nitrogen is associated with the appearance of a red-shifted intramolecular charge transfer peak in the UV-visible spectra. Favorable color indicating properties result from electron-donating substitution at the 2 and 6 positions of pyridine, which provide a greater absorptivity of the red-shifted peak associated with protonation of the pyridine nitrogen. These findings will assist in the design and optimization of these compounds for ion-indicating and pH-sensing applications.
- Chapman, Gala,Solomon, Isaac,Patonay, Gabor,Henary, Maged
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p. 861 - 872
(2015/05/26)
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- One-pot synthesis of indolizine via 1,3-dipolar cycloaddition using a sub-equivalent amount of K2Cr2O7 as an efficient oxidant under base free conditions
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A one-pot method for synthesizing multi-substituted indolizines from α-halo-carbonyl compounds, pyridines and electron deficient alkenes was developed. A sub-equivalent amount of potassium dichromate was used as an oxidant under base free conditions. The transformation developed should be of economic efficiency.
- Wang, Chao,Hu, Huayou,Xu, Juanfang,Kan, Weiqiu
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p. 41255 - 41258
(2015/05/20)
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- NEW MATERIAL FOR TRANSPORTING ELECTRON AND ORGANIC ELECTROLUMINESCENT DEVICE USING THE SAME
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The present invention relates to a novel electron transport material represented by chemical formula 1 and an organic luminescent device using the same. By using the electron transport material, the organic luminescent device which has enhanced luminescent properties and improved electric power consumption by reinforcing driving voltage and inducing increase of power factor can be manufactured.
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Paragraph 0071; 0077; 0078
(2016/10/10)
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- Novel indolizine derivatives with unprecedented inhibitory activity on human farnesyltransferase
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The rational structural modification of new substituted indolizin-3-yl(phenyl)methanones 1a-i, 2a-i and 3a-i has greatly improved human farnesyltransferase inhibition. The para-bromophenyl analog 2f bearing an ester unit on the indolizine ring demonstrates the highest inhibition potential, with IC50 value of 1.3 ± 0.2 μM. The amidic series 1a-i proves to be the most promising for future modulations, particularly at the triple bond level.
- Dumea, Carmen,Belei, Dalila,Ghinet, Alina,Dubois, Jolle,Farce, Amaury,Bcu, Elena
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supporting information
p. 5777 - 5781
(2015/01/08)
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- One-pot two-step synthesis of 1-(ethoxycarbonyl)indolizines via pyridinium ylides
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Pyridinium salts Py+-CH2-EWG (EWG = CO2Et, CONEt2, CN, COMe, COPh) reacted with Michael acceptors Ar-CH=C(CO2Et)(Acc) (Acc = CO2Et, COMe, SO2Me, CONH2) at ambient temperature in the presence of base to give [3 + 2]-cycloadducts by stepwise [3 + 2]-cycloaddition of the intermediate pyridinium ylides. Treatment of the crude reaction mixtures with 1 equiv. of chloranil and atmospheric oxygen in the presence of sodium hydroxide gave 1-(ethoxycarbonyl)indolizines by dehydrogenation and elimination of the acceptor group (Acc). A good yield of indolizine was also obtained from Py +-CH2CN and iPr-CH=C(CO2Et)2, which indicates that this method is not restricted to aromatic Michael acceptors. Structurally related isoquinolinium salts react with Michael acceptors analogously to give pyrrolo[2,1-a]isoquinolines.
- Allgaeuer, Dominik S.,Mayr, Herbert
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supporting information
p. 6379 - 6388
(2013/10/21)
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- THERMOCHROMIC COMPOSITIONS FROM TRISUBSTITUTED PYRIDINE LEUCO DYES
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A thermochromic leuco dye composition contains a leuco dye moiety including one or more tri-aryl substituted pyridines, a UVA developer moiety including at least one UVA developer selected from the group consisting of salicylic acid and derivatives thereof, and biphenyls and derivatives thereof, and a carrier selected from the group consisting of a fatty ester, fatty alcohol, fatty amide, and combinations thereof.
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Paragraph 0035
(2013/04/13)
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- Molecular diversity of cycloaddition reactions of the functionalized pyridinium salts with 3-phenacylideneoxindoles
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The cycloaddition reactions of a series of functionalized pyridinium salts, which were generated from reaction of pyridine with active alkyl halides such as p-nitrobenzyl bromide, N,N-diethyl chloroacetamide and phenacyl bromides with 3-phenacylideneoxindoles in the presence of triethylamine showed very interesting molecular diversities. A series of the functionalized spiro[cyclopropane-1,3′-indolines], and 3-furan-3(2H)-ylidene)indolin-2- ones were successfully prepared depending upon the structures of the pyridinium salts and reaction conditions. The regioselectivity and stereoselectivity of the reactions as well as reaction mechanisms were briefly discussed.
- Fu, Qin,Yan, Chao-Guo
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supporting information
p. 5841 - 5849
(2013/07/27)
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- Regioselective CH bond activation on stabilized nitrogen ylides promoted by Pd(II) complexes: Scope and limitations
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The orthopalladation of N-ylides [HxCyN-CHC-(O)Ar] (HxCyN = pyridine, benzylamine, imidazole, aniline, and phenylpyridine; Ar = aryl) has been studied. The incorporation of the Pd atom to these substrates is regioselective, since the orthopalladation is produced, in most of the cases, only at the aryl ring of the benzoyl group with concomitant C-bonding of the Nylide. The X-ray structure of one representative example is reported. Factors governing the observed orientation are discussed, because this regioselectivity is worthy of note, considering the deactivating nature of the carbonyl group. Two exceptions to the general trend have been observed. The first one is the double metalation of the ylide [PhMe2NCHC(O)Ph], which incorporates one Pd at each Ph. The second one is the palladation of the phenylpyridine derivative, which occurs at the pyridinic 2-phenyl ring and produces a six-membered palladacycle.
- Grande, Loreto,Serrano, Elena,Cuesta, Luciano,Urriolabeitia, Esteban P.
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scheme or table
p. 394 - 404
(2012/04/23)
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- Microwave-assisted, one-pot three component synthesis of 2-phenyl H-imidazo[1, 2-α]pyridine
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A novel synthesis of 2-phenylH-imidazio[1, 2-α] pyridines is described from a one-pot, three-component reaction between pyridine, guanidine (urea or thiourea) and α-bromoketones under microwave irradiation and solvent-free conditions in excellent yields.
- Motevalli, Kourosh,Yaghoubi, Zahra,Mirzazadeh, Roghieh
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experimental part
p. 1047 - 1052
(2012/06/01)
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- Copper acetate monohydrate: A cheap but efficient oxidant for synthesizing multi-substituted indolizines from pyridinium ylides and electron deficient alkenes
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We report a highly practical one-pot method for synthesizing multi-substituted indolizines from ?±-halide carbonyl compounds, pyridines and electron deficient alkenes in the presence of copper acetate monohydrate and sodium acetate in DMF. A variety of function groups are tolerable in standard reaction conditions, including aldehyde. 36 examples were presented. The yield of indolizine was from moderate to high. Furthermore, multi-substituted indolizines can be prepared at gram scale by this method.
- Hu, Huayou,Feng, Junjun,Zhu, Yulan,Gu, Ning,Kan, Yuhe
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p. 8637 - 8644
(2015/02/19)
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- Pyridine-mediated, one-pot, stereoselective synthesis of acyclic enaminones
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A new one-pot, three-component reaction of phenacyl pyridinium bromides, various primary aromatic amines, and phenyl glyoxal or ethyl glyoxalate for the stereoselective synthesis of acylic enaminones in good chemical yields is described.
- Ghandi, Mehdi,Jameà, Amir Hossein
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experimental part
p. 4005 - 4007
(2011/08/21)
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- Amberlite-IRA-402 (OH) ion exchange resin mediated synthesis of indolizines, pyrrolo [1,2-a] quinolines and isoquinolines: Antibacterial and antifungal evaluation of the products
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A number of indolizines and pyrrolo[1,2-a]quinolines/isoquinolines were prepared from phenacyl pyridinium, quinolinium and isoquinolinium salts derived fromthe reaction of the heterocycles with 2-bromo acetophenone with alkynes and alkenes using amberlite-IRA-402 (OH) ion exchange resin as the base. Antibacterial and antifungal studies were carried out against thirteen bacterial and four fungal strains, which revealed that three derivatives (4a, 4b, 7a) out of fifteen are effective against all the thirteen strains and one derivative, 10, showed dual antibactericidal and antifungal efficacy.
- Hazra, Abhijit,Mondal, Shyamal,Maity, Arindam,Naskar, Subhendu,Saha, Pritam,Paira, Rupankar,Sahu, Krishnendu B.,Paira, Priyankar,Ghosh, Soma,Sinha, Chandrima,Samanta, Amalesh,Banerjee, Sukdeb,Mondal, Nirup B.
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body text
p. 2132 - 2140
(2011/06/21)
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- Effect of structure of nucleophile and substrate on the quaternization of heterocyclic amines
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The influence of the nature of the quaternizing agent and substrate on the quaternization of heterocyclic amines, derivatives of pyridine, ss-picoline, nicotinamide, pyridoxine, was studied. The synthesized compounds were characterized by IR spectroscopy and elemental analysis. The conclusions were made about the effect of the structure of nucleophile and substrate on the process of quaternization reaction. Pleiades Publishing, Ltd., 2010.
- Zhuravlev,Verolainen,Voronchikhina
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experimental part
p. 1025 - 1028
(2011/01/11)
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- Microwave-assisted, one-pot reaction of pyridines, -bromoketones and ammonium acetate: An efficient and simple synthesis of Imidazo[1,2- a ]-pyridines
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A novel and efficient synthesis of imidazo[1,2-a]pyridines is described. N-Phenacylpyridinium bromides, which were prepared in situ from the addition of pyridines to -bromoketones, undergo nucleophilic addition of ammonium acetate under microwave irradiation and solvent-free conditions to afford the corresponding imidazo[1,2-a]pyridines in excellent yields.
- Adib, Mehdi,Mohamadi, Ali,Sheikhi, Ehsan,Ansari, Samira,Bijanzadeh, Hamid Reza
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experimental part
p. 1606 - 1608
(2010/08/20)
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- Novel one-pot three component reaction for the synthesis of [2-(alkylsulfanyl)imidazo[1,2-a]pyridin-3-yl](aryl)methanone
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A one-pot, three-component reaction between pyridine, phenacyl bromide, and thiocyanate is described. The reaction afforded the corresponding special type of fully substituted imidazo[1,2-a]pyridine derivatives in good yields without using any catalyst or activation.
- Kianmehr, Ebrahim,Ghanbari, Mohammad,Niri, Mehri Nadiri,Faramarzi, Reza
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experimental part
p. 41 - 44
(2010/10/03)
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- Synthesis of zwitterionic salts of pyridinium-meldrum acid and barbiturate through unique four-component reactions
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An efficient synthetic procedure for the preparation of the unusual charge-separated pyridinium-Meldrum acid and N,N-dimethylbarbiturate acid zwitterionic salts was developed though a unique one-pot fourcomponent reaction involving pyridine, aromatic aldehyde, Meldrum acid or N,N-dimethylbarbituric acid, and p-nitrobenzyl bromide in acetonitrile. By varying combinations of four components involving nitrogencontaining heterocycles, we conveniently established reactiveα-halomethylene compounds, aldehydes and β-dicarbonyl compounds a library of zwitterionic salts.
- Wang, Qi-Fang,Hui, Li,Hou, Hong,Yan, Chao-Guo
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supporting information; experimental part
p. 260 - 265
(2010/08/05)
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- Electrophilic and nucleophilic side chain fluorination of para-substituted acetophenones
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para-Substituted α-fluoroacetophenones have been synthesised by three different routes. Electrophilic fluorination of trimethylsilyl enol ethers of acetophenones using Selectfluor (F-TEDA-BF4, 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis-(tetrafluoroborate)) gave high to moderate yield depending on the electronic properties of the substituents. F-TEDA-BF4 mediated fluorination of acetophenones in methanol resulted in a mixture of α-fluoroacetophenones and the corresponding 2-fluoro-1,1-dimethyl acetals. The dimethyl acetals were hydrolysed using trifluoroacetic acid in water to maximise the yield of the product. Nucleophilic fluorination of α-bromoacetophenones using tetrabutylammonium hydrogen bifluoride (TBABF) led to moderate yield when having electron-donating substituents, whereas low yields were experienced when more electron-withdrawing substituents were introduced.
- Fuglseth, Erik,Thvedt, Thor H?kon Krane,M?ll, Maria F?rde,Hoff, B?rd Helge
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p. 7318 - 7323
(2008/12/21)
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- Stability of 1-phenacylpyridinium and 1-(2-hydroxy-2-phenylvinyl)pyridinium cations
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1-Phenacylpyridinium cation, C5H5N+-CH2COC6H 4R-p, is the only tautomeric form detected in DMSO solution. This shows that the vicinity of the strong electron-acceptor pyridinium group has a minor effect on acidity of the methylene protons in 1-phenacylpyridinium salts. It was found that substitution in the benzene ring does not affect the tautomeric equilibrium. Although 1-(2-hydroxy-2-phenylvinyl)pyridinium cation is stabilized by conjugation, the ab initio calculated energies confirm the higher stability of the keto form (electron-acceptor substituents slightly increase stability of the enol form). It was found that 1-(2-hydroxy-2-phenylvinyl)pyridinium cation is not planar. Calculations show that electrostatic attraction between the onium nitrogen and hydroxy oxygen atoms takes place in this cation.
- Osmialowski,Janota,Gawinecki
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p. 169 - 177
(2007/10/03)
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- Streptogramin derivatives, preparation method and compositions containing same
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Group B streptogramin derivatives of general formula (I): wherein Ra, Rb, Rc, Rd, R1, R2 and Y are as defined in the description, including preparation methods and compositions containing same. Such derivatives are particularly useful as antimicrobial agents, optionally combined with at least one group A streptogramin derivative.
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- Studies with functionally substituted heteroaromatics: The chemistry of N-phenylhydrazonylalkylpyridinium salts and of phenylhydrazonylalkylbenzoazoles
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2-Pyrid-1-yliniumacetonitrile bromide 1a and 2-pyrid-1- ylinium-1-phenylethanone bromide 1b coupled with benzenediazonium chloride to yield the corresponding phenylhydrazones 3a, b. Similarly, compounds 2a-c also coupled with aryldiazonium chloride, yielding the arylhydrazones 10a-b, which were used as precursors for the synthesis of azolypyfidazinones 11a, b. Compounds 3a, b were converted into 1,2,4,5-dihydrotetrazines 4a, b on refluxing in acetonitrile in the presence of ammonium acetate. Refluxing 3a in dimethylformamide resulted in the formation of the 3-cyanoindazole 6. Compound 3a was converted to pyrazole 8 on treatment with the enaminone 7, and to hydrazonyl bromide 9 on heating in dioxane/acetonitrile. Compound 12 was synthesized from the reaction of 10b with ethanolic aqueous sodium hydroxide.
- Abdel-Khalik, Mervat Mohammed,Elnagdi, Mohammed Hilmy,Agamy, Samia Michel
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p. 1166 - 1169
(2007/10/03)
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- Kinetics and Mechanism of the Pyridinolysis of Phenacyl Bromides in Acetonitrile
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Kinetic studies of the reactions of substituted phenacyl bromides (YC6H4COCH2Br) with pyridines (XC5H4N) are carried out in acetonitrile at 45.0°C. A biphasic Bronsted plot is obtained with a change in slope from a large (βX ? 0.65-0.80) to a small (βX ? 0.36-0.40) value at pKao = 3.2-3.6, which can be attributed to a change in the rate-determining step from breakdown to formation of a tetrahedral intermediate in the reaction path as the basicity of the pyridine nucleophile increases. This mechanism is supported by the faster rates with pyridines than with anilines and the change of cross-interaction constant ρXY from a large positive (ρXY ? +1.4) to a small positive (ρXY ? +0.1) value. The large magnitude of Hammett ρX (= -5.5 to -6.9) values for the pyridines with electron-withdrawing substituents and positive deviations of the π-acceptors, p-CH3CO and p-CN, are quite similar to those for the pyridinium ion formation equilibria. The activation parameters are also in line with the proposed mechanism.
- Koh, Han Joong,Han, Kwang Lae,Lee, Hai Whang,Lee, Ikchoon
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p. 4706 - 4711
(2007/10/03)
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- Michael addition versus 1,3-cycloaddition reactions of pyridinium ylides with (arylmethylene)isoxazol-5-ones: Diastereoselective formation of 4-[1-aryl-2-(1-pyridinio)ethyl]isoxazolium-5-olates
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The reactions of (arylmethylene)isoxazol-5-ones 1 with pyridinium ylides 2 lead to the diastereoselective formation of olates 4. The reasons for the favored Michael addition and the unsuccessful subsequent cyclization to fused O-heterocycles are discussed on the basis of X-ray analysis as well as 1H-NMR and chemical evidences. VCH Verlagsgesellschaft mbH, 1997.
- Risitano, Francesco,Grassi, Giovanni,Bruno, Giuseppe,Nicolo, Francesco
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p. 441 - 445
(2007/10/03)
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