- Synthesis and optical properties of new 2-oxo-4-vinyl-2H-chromene-3-carbonitrile dyes
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New derivatives of 2-oxo-4-vinyl-2H-chromene-3-carbonitrile have been synthesized by the Knoevenagel reaction of 4-methyl-2-oxo-2H-chromene-3-carbonitrile with aromatic and heteroaromatic aldehydes. The first hyperpolarizability β for the obtained compoun
- Levchenko, Konstantin S.,Chudov, Konstantin A.,Zinoviev, Evgeni V.,Lyssenko, Konstantin A.,Fakhrutdinov, Artem N.,Demin, Dmitri U.,Poroshin, Nikolay O.,Zhukova, Anna A.,Shmelin, Pavel S.,Grebennikov, Evgeni P.
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- Easy solventless synthesis of new mono and bis amino-5H-chromeno [3,4-c] pyridin-5-one derivatives
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A new series of mono and bis amino-5H-chromeno [3,4-c] pyridin-5-one derivatives were prepared via the reaction of primary amines with 4-(2-(dimethylamino)vinyl)-2-oxo-2H-chromene-3-carbonitrile 3. The X-rays structures of 4-(hexylamino)-5H-chromeno[3.4-c
- Kibou, Zahira,Villemin, Didier,Lohier, Jean-Fran?ois,Cheikh, Nawel,Bar, Nathalie,Choukchou-Braham, Noureddine
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- Studies with polyfunctionally substituted heteroaromatics: Synthesis of new heterocyclic aromatic amines as potential intermediates for preparation of dyes for thermal diffusion printing
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Several new dibenzopyrans as well as novel thiadiazaacenaphthenes are obtained via 4 + 2 addition of the thienocoumarins (1) and thienopyridazines (2) to electron-poor olefins.
- Erian, Ayman Wahba,Hafez, Ebtisam Abdul Aziz,Darwish, Elham Sayed,Elnagdi, Mohamed Hilmy
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- On the Condensation of 2,2-Difluoro-4-methyl-benzo[d]-1,3,2-dioxaborines with Cyano Acetic Acid Derivatives. Formation and Transformation of 3-Cyano-4-methyl-benzo [b]pyran-2-ones and their 2-Imine Precursors
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By condensation of 2,2-difluoro-4-methyl-benzo[d]-1,3,2-2H-dioxaborines(12) with cyano acetic acid derivatives in presence of weak bases, 3-cyano-4-methyl-benzo[b]pyran-2-ones (13) or their 3-cyano-4-methyl-benzo[b]pyran-2-imine precursors (14) are available in satisfactory yields.
- Boutome,Hartmann
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- One-Pot Green Synthesis of 2-Oxo-2H-chromene-3-carbonitriles Using Dual-Frequency Ultrasonication
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Abstract: A green synthesis of 2-oxo-2H-chromene-3-carbonitriles has been carried out in one step by reacting 2-hydroxybenzaldehydes or 2-hydroxyacetophenones with ethyl cyanoacetate under dual-frequency ultrasonica-tion (ultrasonic bath of 40 KHz and probe of 20 KHz). The compounds were obtained in very high yield, and their structures were confirmed by IR and NMR data.
- Aruna,Kumar, S.,Sharma, S. P.,Vashisht, N.
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p. 1508 - 1512
(2021/10/26)
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- Palladium-Catalyzed Regioselective and Diastereoselective C-Glycosylation by Allyl-Allyl Coupling
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A Pd-catalyzed C-glycosylation reaction was developed by allyl-allyl coupling process using Achmatowicz rearrangement products as donors and methylcoumarins as acceptors under mild conditions. This method featured regio- and diastereoselectivities, stereo
- Li, Junhao,Zheng, Nan,Duan, Xuelun,Li, Rui,Song, Wangze
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supporting information
p. 846 - 850
(2020/12/13)
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- Zirconium(IV) oxychloride: A simple and efficient catalyst for the synthesis of chromen-2-one derivatives
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The present work explores a highly efficient, environmental friendly, green protocol for the synthesis of chromen-2-one derivatives (3a-m) by the condensation of salicylaldehydes with various active methylene compounds using zirconium (IV) oxychloride as catalyst. This is a convenient and rapid method for Knoevenagel condensation and this methodology offers several advantages including shorter reaction time, milder conditions, inexpensive catalyst, simple operational procedure and allowed to achieve the desired products in excellent yields. The structures of all the synthesized compounds were confirmed by spectral data.
- TASQEERUDDIN,ASIRI, YAHYA I.,SHAHEEN
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p. 2611 - 2616
(2020/10/22)
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- Iridium-catalyzed direct asymmetric vinylogous allylic alkylation
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The catalytic asymmetric vinylogous allylic alkylation of α,β-unsaturated lactones (including coumarins) was achieved with excellent regio- and enantioselectivity. Transformations of the product were carried out by means of the versatile terminal olefin and lactone moieties. The synthetic application of the present methodology was showcased by the asymmetric synthesis of an advanced synthetic Merck intermediate toward a new drug candidate.
- Shi, Chang-Yun,Xiao, Jun-Zhao,Yin, Liang
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supporting information
p. 11957 - 11960
(2018/11/02)
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- Synthesis, characterization, antimicrobial and antioxidant activities of the homocyclotrimer of 4-oxo-4h-thieno[3,4-c]chromene-3-diazonium sulfate
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The in situ formed 4-oxo-4H-thieno[3,4-c]chromene-3-diazonium sulfate (5) in the coupling reactions involving the parent 2-aminothiophene (4) and various phenolic and arylamines’ couplers, readily undergoes homocyclotrimerization at low temperature to aff
- Fondjo, Emmanuel Sopbue,Sorel, Djeukoua Dimo Kamal,Jean-de-Dieu, Tamokou,Joseph, Tsemeugne,Sylvian, Kouamo,Doriane, Ngouanet,Rodolphe, Chouna Jean,Pepin, Nkeng-Efouet-Alango,Jules-Roger, Kuiate,Arnaud, Ngongang Ndjintchui,Lucas, Sondengam Beibam
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- FeCl3-catalyzed cascade reaction: An efficient approach to functionalized coumarin derivatives
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An efficient and environmentally benign synthesis of 3-substituted or 3,4-disubstituted coumarins was accomplished via iron(III) chloride-catalyzed cascade reactions of salicylaldehydes and activated methylene compounds. The reaction preceded cleanly under mild reaction conditions to provide the desired coumarin derivatives in good to excellent yields.
- He, Xinwei,Yan, Zhenglei,Hu, Xiaoqian,Zuo, Yin,Jiang, Chang,Jin, Lei,Shang, Yongjia
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supporting information
p. 1507 - 1514
(2014/05/20)
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- Iodine-mediated one-pot synthesis of 3-cyanocoumarins and 3-cyano-4-methylcoumarins
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2-Hydroxybenzaldehydes 1a-e on reaction with malononitrile (2) in the presence of iodine as catalyst give 3-cyanocoumarins 3a-e in one step under thermal heating as well as under microwave irradiation. The latter conditions are much more efficient in terms of time (2-5 min) and yield as compared to the thermal conditions (2-2.5 h). Following a similar procedure, 3-cyano-4-methylcoumarins 3f-i were also prepared by the reaction of 2-hydroxyacetophenones 1f-i with 2.
- Sharma, Dinesh,Makrandi, Jagdish K.
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p. 527 - 531
(2014/06/10)
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- Enantioselective intramolecular [2+2] photocycloaddition reactions of 4-substituted coumarins catalyzed by a chiral Lewis acid
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Eight coumarins, which carry a terminal alkene tethered by a CH 2XCH2 group to their 4-position (X=CH2, CMe2, O, S, NBoc, NZ, NTs, NBn), were synthesized in overall yields of 51-80 %. Starting materials for the syntheses were either commercially available 4-hydroxycoumarin or 4-formylcoumarin. The intramolecular [2+2] photocycloaddition of these coumarins gave diastereoselectively products with a tetracyclic 3,3a,4,4a-tetrahydro-1H-cyclopenta[2,3]cyclobuta[1,2-c]chromen-5(2H) -one skeleton. Direct irradiation at λ=300 nm in dichloromethane (c=10 mM) led to product formation in good yields for most substrates, presumably via a singlet excited state intermediate. Due to the low coumarin absorption at λ >350 nm the photocycloaddition was slow upon irradiation at λ=366 nm. Addition of a chiral oxazaborolidine-based Lewis acid (50 mol %) increased the reaction rate at λ=366 nm and induced a significant enantioselectivity in the [2+2] photocycloaddition. Six out of eight coumarin substrates (X=CH2, CMe2, O, NBoc, NZ, NTs) gave the respective products in yields of 72-96 % and with 74-90 % enantiomeric excess (ee) upon irradiation in dichloromethane (c=20 mM) at -75 °C. The Lewis acid presumably acts by coordination to the coumarin carbonyl oxygen atom, which leads to a bathochromic shift (redshift) of the UV absorption and which increases the singlet state lifetime. A second electrostatic interaction of the hydrogen atom at C3 with the oxygen atom of the oxazaborolidine is likely. Copyright
- Brimioulle, Richard,Guo, Hao,Bach, Thorsten
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supporting information; experimental part
p. 7552 - 7560
(2012/07/30)
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- Silicon-assisted O-heterocyclic synthesis: Mild and efficient one-pot syntheses of (E)-3-benzylideneflavanones, coumarin-3-carbonitriles / carboxamides, and benzannulated spiropyran derivatives
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A new general and efficient method for the one-pot synthesis of (E)-benzylideneflavanones, dibenzospiropyrans and coumarin-3-carbonitriles/ carboxamides is achieved through tandem aldol-cyclocondensation of o-hydroxyaryl carbonyl compounds with aryl aldeh
- Salama, Tarek A.,Ismail, Mohamed A.,Khalil, Abdel-Galil M.,Elmorsy, Saad S.
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p. 242 - 253
(2013/02/23)
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- Migratory decarboxylative coupling of coumarins: Synthetic and mechanistic aspects
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On the move: Decarboxylative coupling of allyl 4-methyl-3-carboxycoumarins provides the products of γ-allylation of the methyl group rather than the typical regiospecific α-allylation. Mechanistic studies show that intramolecular proton transfer from the 4-methyl group to the 3-carboxylate allows allylation of the remote methyl group. The resulting 4-butenyl-3-carboxyl coumarin undergoes Pd0-catalyzed decarboxylation to provide the observed products (see scheme). Copyright
- Jana, Ranjan,Partridge, James J.,Tunge, Jon A.
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supporting information; experimental part
p. 5157 - 5161
(2011/07/30)
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- One-pot greener protocol for the synthesis of substituted coumarins
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An expeditious one-pot procedure for the synthesis of substituted coumarins under microwave irradiation is accounted. The method describes an easy and fast method for the synthesis of substituted acetoxy coumarins which are very good fluorophores for medical as well as industrial applications. It makes use of easily available reagents such as triethylamine and acetic anhydride as catalyst. The method finds good applications for the synthesis of multisubstituted coumarins.
- Ranjith, Choorikkat,Paul, Nidhin,Vijayan
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experimental part
p. 235 - 238
(2011/11/30)
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- Synthesis of 3-cyano and 3-cyano-4-methyl-coumarins using phase transfer catalysis
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Synthesis of 3-cyano and 3-cyano-4-methylcoumarins have been achieved by the reaction of 2-hydroxybenzaldehydes/2-hydroxyacetophenones with malanonitrile in biphase medium using phase transfer catalysis.
- Seema,Kumar, Surender,Makrandi
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p. 1307 - 1308
(2007/10/03)
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- Gas-phase pyrolysis of 2-heteroaromatic-1-dimethylaminoethylenes: kinetic and mechanistic study
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Gas-phase pyrolysis reactions of 4(2′-dimethylaminoethenyl)-2-oxo-2H- benzo[b]pyran-3-carbonitrile (1), 4(2′-dimethylaminoethenyl)-2-oxo-2H- naphtho[1,2-b]pyran-3-carbonitrile (2), 1,6-dihydro-4-(2′-dimethylaminoethenyl)-6- oxo-1-phenylpyridazine-3,5-dica
- Elnagdi, Mohamed H.,Al-Awadi, Nouria A.,Kumar, Agith,Khalik, Mervat Abdul
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- Reactivity of condensed thiophenes in the Diels-Alder reaction: The reactivity of 3-aminothieno [3,4:3',4'] benzo [b] pyranone; 3-aminothieno [3,4-c] quinoline and of 5-amino-7-substituted thieno [3,4-d] pyridazinone toward electron-poor olefins and acetylenes
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The thieno [3,4:3',4'] benzo [b] pyranone (3b) and the thieno [3,4-c] quinoline (3c) are prepared via reacting 4-methylcoumarin-3-carbonitrile (9a) and 4-methyl-2-oxo-1,2-dihydroquinolin-3-carbonitrile (9b) with elemental sulphur, Similarly the thieno [3,4:3',4'] naphtho [1,2-b] pyran (11) is prepared from reaction of (10) and elemental sulphur. The condensed thiophenes (3b,c) and (11) react with a variety of electronpoor olefins to yield products of addition followed by hydrogen sulphide elimination. The reaction of (3b,c) and (11) with ethyl propiolate in refluxing dioxane/acetic acid mixture affords the condensed thiepins (24a,c). The nature of product of reaction of (3b,c) and (11) with dimethyl acetylenedicarboxylate is dependent on applied reaction conditions. Thus the reaction of (3b,c) and (11) with dimethyl acetylenedicarboxylate in refluxing dioxane afforded condensed thiepins while at 250°C products of addition and desulfurization are obtained. Whereas thienopyridazinones (1a,b) react with ethyl acrylate and diethyl fumarate to yield thiadiazaacenaphthenones (31a-c) respectively, compounds (1a,b) react with N-phenylmaleimide to yield phthalazine (32). The thienopyridazinone (1c) failed to react with the same reagents under similar conditions.
- Al-Omran, Fatima,Khalik, Mervat Mohammed Abdel,Al-Awadhi, Hanan,Elnagdi, Mohammed Hilmy
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p. 11915 - 11928
(2007/10/03)
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- Simple and efficient one-pot preparation of 3-substituted coumarins in water
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3-Cyanocoumarin and seven derivatives [4-Me; 6-NO2; 7-OH; 7-OMe; 8-OH; 5,7-OMe; 6,7-(-CH=CH-)-2] and eight coumarins substituted at C-3 (CO2Et; NO2; Ph; p-NO2-C6H4; Ph-SO2; 2-pyridyl; 2-thienyl; 2-benzothiazolyl) were prepared, on multigram scale by a one-pot procedure in water alone, by the Knoevenagel reaction of o-hydroxyaryl aldehydes and o-hydroxyacetophenone with acetonitriles. The yields are high and the procedure does not require organic solvents. The reactions carried out in heterogeneous aqueous phase, sometimes in the presence of a surfactant, always have higher yields than the same reactions executed in homogeneous ethanolic medium.
- Brufola, Gianluca,Fringuelli, Francesco,Piermatti, Oriana,Pizzo, Ferdinando
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p. 1257 - 1266
(2007/10/03)
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- NITRILES IN HETEROCYCLIC SYNTHESIS: NOVEL SYNTHESIS OF BENZOCOUMARIN AND OF BENZOPYRANOQUINOLINE DERIVATIVES
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Novel syntheses of benzocoumarins and benzopyranoquinolines utilizing 3-cyano-4-methylcoumarin and pyranoquinolin are reported.
- Hafez, Ebtisam Abdel Aziz,Elnagdi, Mohamed Hilmy,Elagamey, Abdel Ghani Ali,El-Taweel, Fathy Mohamed Abdel Aziz
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p. 903 - 907
(2007/10/02)
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