91059-67-5Relevant academic research and scientific papers
Packing-induced solid-state fluorescence and thermochromic behavior of peptidic luminophores
Pramanik, Apurba,Haldar, Debasish
, p. 389 - 395 (2017)
The effect of packing on the solid state fluorescent propensities of peptidic luminophores has been investigated. A series of peptides containing 6-nitro-coumarin-3-carboxylic acid and α-aminoisobutyric acid (Aib) has been synthesized to study the structure-property relationship and stimuli responsive emission properties of the luminophores. In spite of the presence of a coumarin chromophore, peptide 2 exhibits no solid state fluorescence. The alkyl chains of Aib affect the solid state molecular packing modes and optoelectronic properties significantly. However, the fluorescence microscopy confirmed the change of blue fluorescence of peptide 3 in crystal and in amorphous states. The X-ray crystallography sheds some light on the molecular orientation, packing and the diverse degree of π-π stacking orbital overlap of adjacent coumarin chromophores of the peptide 3. Irrespective of coumarin chromophore, the peptides exhibit different packing-induced solid state emission properties varying from one peptide to another, which highlights the effect of Aib side chains.
Topology-Controlled AIEE of Iminocoumarin Luminophores
Chattapadhyay, Deepta,Mondal, Sahabaj,Kumar, Santosh,Haldar, Debasish
, p. 2723 - 2728 (2021)
Aggregation-induced emission enhancement (AIEE) is an unusual phenomenon where luminophores show a higher photoluminescence efficiency in the aggregated and solid state. We report the design and synthesis of a series of luminophores 1–4 with imine functionality at 6 position of coumarin and studied their AIE propensities on self-assembly. The effect of the topology of the phenolic hydroxyl group on the emission behaviour of the luminophores has been investigated. The imines show significant solvatochromism with high emission in non-polar solvents, whereas the emission gets quenched in the polar solvent. The fluorescence in the toluene-hexane mixture arises due to the aggregation of fluorophores and falls under the category of AIEE. Not only the solution state emission of the isomeric iminocoumarin luminophores is notably varied, but also their solid-state emission found to be significantly different from each other. Moreover, the iminocoumarin 1 selectively recognizes Fe(III) over Fe(II) with a prominent color change. In situ oxidation of Fe(II) with H2O2 exhibits the same effect like Fe(III) and developed a chemical combinational logic gate.
3-carboxylic acid and formyl-derived coumarins as photoinitiators in photo-oxidation or photo-reduction processes for photopolymerization upon visible light: Photocomposite synthesis and 3d printing applications
Dumur, Frédéric,Gigmes, Didier,Graff, Bernadette,Hamieh, Tayssir,Lalevée, Jacques,Noirbent, Guillaume,Rahal, Mahmoud,Toufaily, Joumana
, (2021/06/16)
In this paper, nine organic compounds based on the coumarin scaffold and different substituents were synthesized and used as high-performance photoinitiators for free radical pho-topolymerization (FRP) of meth(acrylate) functions under visible light irradiation using LED at 405 nm. In fact, these compounds showed a very high initiation capacity and very good polymerization profiles (both high rate of polymerization (Rp) and final conversion (FC)) using two and three-component photoinitiating systems based on coum/iodonium salt (0.1%/1% w/w) and coum/iodonium salt/amine (0.1%/1%/1% w/w/w), respectively. To demonstrate the efficiency of the initiation of photopolymerization, several techniques were used to study the photophysical and photochemical properties of coumarins, such as: UV-visible absorption spectroscopy, steady-state photolysis, real-time FTIR, and cyclic voltammetry. On the other hand, these compounds were also tested in direct laser write experiments (3D printing). The synthesis of photocomposites based on glass fiber or carbon fiber using an LED conveyor at 385 nm (0.7 W/cm2 ) was also examined.
Co-immobilization of Laccase and TEMPO in the Compartments of Mesoporous Silica for a Green and One-Pot Cascade Synthesis of Coumarins by Knoevenagel Condensation
Mogharabi-Manzari, Mehdi,Amini, Mohsen,Abdollahi, Mohammad,Khoobi, Mehdi,Bagherzadeh, Ghodsieh,Faramarzi, Mohammad Ali
, p. 1542 - 1546 (2018/02/28)
Co-immobilization of bio- and chemocatalysts produces sustainable, recyclable hybrid systems that open new horizons for green cascade approaches in organic synthesis. Here, the co-immobilization of laccase and 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) in mesoporous silica was used for the one-pot aqueous synthesis of 30 coumarin-3-carboxylate derivatives under mild conditions through the condensation of in situ oxidized 2-hydroxybenzyl alcohols and malonate derivatives. A maximum yield was obtained after incubating at pH 6.0 and 45 °C for 24 h. An efficient organic synthesis was catalyzed by the hybrid catalyst in 10 % organic solvent. More than 95 % of the initial activity of the enzyme was preserved after 10 cycles, and no significant catalyst deactivation occurred after 10 runs. This new system efficiently catalyzed the in situ aerobic oxidation of salicyl alcohols, followed by Knoevenagel condensation, which confirmed the possibility of producing efficient hybrid catalysts by co-immobilization of catalytic species in mesoporous materials.
Novel nano-titania embedded on graphite (nano-TiO2@Cg) as an efficient, eco-friendly, and recyclable catalyst for one-pot, solvent-free synthesis of 4-aryl-3,4-dihydroquinolin-2(1H)-ones, 3-methyl-4-aryl/alkyl-2,4,5,7-tetrahydropyrazolo[3,4-b]pyridin-6-ones, and coumarin-3-carboxylic esters
Nikoofar, Kobra,Molaei Yielzoleh, Fatemeh
, p. 7353 - 7367 (2018/08/29)
Abstract: A novel acid catalyst has been synthesized by commercial anatase phase nano-TiO2 and graphite (nano-TiO2@Cg) via a simple procedure and characterized by Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy, and potentiometric titration techniques. It has been utilized as a convenient nano-catalyst to accelerate the one-pot, solvent-free, three-component reaction of Meldrum’s acid, aromatic amines (5-methylpyrazol-3-amine), and various aromatic aldehydes to form 4-aryl-3,4-dihydroquinolin-2-(1H)-ones and 3-methyl-4-aryl/alkyl-2,4,5,7-tetrahydropyrazolo[3,4-b]pyridin-6-ones, respectively. The catalytic activity has also examined for the preparation of coumarin-3-carboxylic esters from Meldrum’s acid, salicylaldehydes, and alcohols successfully. Low catalyst loading, clean process without utilizing any hazardous solvent, easy workup procedure, reusability and recyclability of the nano-catalyst within four runs without activity loss, high yields of the products, in addition with utilizing a vast range of substrates are some highlighted points of the reported protocols. Graphical abstract: [Figure not available: see fulltext.]
Coumarin-3-carboxylic acid ester derivative preparation method
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Paragraph 0045; 0062-0066, (2017/02/02)
The invention discloses a preparation method for a coumarin-3-carboxylic ester derivative shown as the formula (I) or the formula (II) in the specification. The method comprises the step that under the existence of FeCl3 being used as a catalyst, salicylaldehyde derivative shown as the formula (III) in the specification and 2-hydroxy-1-naphthaldehyde shown as the formula (IV) in the specification are in contact reaction with alcohol and meldrum's acid which have a general formula, namely R2OH. Through the fact that the salicylaldehyde derivative, the 2-hydroxy-1-naphthaldehyde, the alcohol or the meldrum's acid is catalyzed by FeCl3 in multi-component contact reaction under a relatively temperate condition, the coumarin-3-carboxylic ester derivative with relatively high productivity is synthesized in relatively short reaction time, and the method is simple in step, efficient and environment-friendly, and completely meets the concept of green chemistry.
Synthesis of coumarin-3-carboxylic esters via FeCl3-catalyzed multicomponent reaction of salicylaldehydes, Meldrum's acid and alcohols
He, Xinwei,Shang, Yongjia,Zhou, Yao,Yu, Zhiyu,Han, Guang,Jin, Wenjing,Chen, Jiaojiao
, p. 863 - 868 (2015/01/30)
A FeCl3-catalyzed multicomponent reaction was developed for the facile synthesis of coumarin-3-carboxylic ester derivatives in a highly atom-economic and environmentally friendly way. Using simple and cheaply available salicylaldehydes, Meldrum's acid and alcohols as the starting materials, the method needs no extra additives and features wide substrate scope, good functional group tolerance and mild reaction conditions.
Synthesis of methyl (E)-2-nitromethylcinnamates derived from baylis-hillman acetates and conversion into several coumarin derivatives
Hong, Wan Pyo,Lee, Kee-Jung
, p. 33 - 38 (2007/10/03)
Fast and easy access to methyl (E)-2-nitromethylcinnamates, from the corresponding Baylis-Hillman acetates with NaNO2 in DMF is described. Several ortho-chloro-2-nitromethylcinnamates undergo intramolecular aromatic substitution reaction follow
One-pot preparation of coumarins by Knoevenagel condensation in solvent-free condition under microwave irradiation
Balalaie, Saeed,Nemati, Navid
, p. 67 - 72 (2007/10/03)
3-Substituted coumarins were prepared by the Knoevenagel reaction of 2-hydroxybenzaldehyde derivatives and 2-hydroxy-1-naphthaldehyde in the presence of ammonium aceteate on basic alumina or silica gel under microwave irradiation. High yields, low reaction times, being environmentally friendly, elimination of organic base and solvent are advantages of this method.
5-Arylidene 1,3-Dimethylbarbituric Acid Derivatives, Mild Organic Oxidants for Allylic and Benzylic Alcohols
Tanaka, Kiyoshi,Chen, Xing,Kimura, Teiji,Yoneda, Fumio
, p. 60 - 69 (2007/10/02)
Various 5-arylidene 1,3-dimethylbarbituric acid derivatives and closely related compounds were synthesized as models of redox coenzymes and used for oxidation of alcohols.Under mild neutral conditions, 5-arylidene 1,3-dimethylbarbituric acid derivatives, especially those having an electron-withdrawing group on the aromatic ring, effectively oxidized allylic and benzylic alcohols to the corresponding carbonyl compounds.The relationship between the oxidizing ability and the structure of the oxidant (coenzyme model) was investigated and it was found that the electron density on the carbon-carbon double bond is a critical factor for the oxidation.In the case of the deuterium-labeled compound, the observed value of normal and primary isotope effect was 3.3 and so it was concluded that mechanism of this oxidation mainly involves the hydride transfer from the alcohol.An electrochemical investigation was also carried out and the redox potentials of the coenzyme models, 5-arylidene 1,3-dimethylbarbituric acid derivatives and related compounds, were measured.Keywords - 5-arylidene 1,3-dimethylbarbituric acid; coenzyme model; oxidation; allylic alcohol; benzylic alcohol; oxidation mechanism; hydride transfer; primary isotope effect; cyclic voltammetry; redox potential
