- Organo Photoinduced Decarboxylative Alkylation of Coumarins with N-(Acyloxy)phthalimide
-
A metal-free and mild, photoinduced decarboxylative 4-position alkylation of coumarins has been reported. Photoinduced single electron transfer has been initiated by utilizing the visible-light absorptivity of Eosin Y for a reductive generation of alkyl r
- Tripathi, Krishna N.,Belal, Md.,Singh, Ravi P.
-
-
Read Online
- Iodine-mediated one-pot synthesis of 3-cyanocoumarins and 3-cyano-4-methylcoumarins
-
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.
-
-
Read Online
- Sonochemistry as a General Procedure for the Synthesis of Coumarins, Including Multigram Synthesis
-
This study describes a general procedure for the synthesis of different coumarins via sonochemistry using active methylene compounds and 2-hydroxybenzaldehydes or resorcinol. The application of sonochemistry for the synthesis of these compounds was also very effective on a multigram scale with a higher yield, higher amount of crystalline compound, and shorter reaction time compared with the compounds obtained using the classical procedures.
- Da Silveira Pinto, Ligia S.,De Souza, Marcus V. N.
-
-
Read Online
- Investigation of the Relationship between H2O2 and HClO in Living Cells by a Bifunctional, Dual-ratiometric Responsive Fluorescent Probe
-
As two important reactive oxygen species, hydrogen peroxide (H2O2) and hypochlorous acid (HClO) play vital roles in many physiological and pathological processes. However, the relationship between these two species is seldom investigated, in part, because
- Han, Jinliang,Liu, Xingjiang,Song, Xiangzhi,Wang, Benhua,Wang, Jingpei,Wang, Wei,Xiong, Haiqing
-
-
Read Online
- ZrCl4/[bmim]BF4-catalyzed condensation of salicylaldehydes and malononitrile: Single-step synthesis of 3-cyanocoumarin derivatives
-
Figure represented. A versatile and efficient single-step route to 3-cyanocoumarins via Knoevenagel condensation of salicylaldehydes and malononitrile using ZrCl4 as the catalyst (15 mol %) in ionic liquid 1-(n-butyl)-3-methylimidazolium tetrafluoroborate as reaction medium and catalyst is described. The novel procedure features single step, short reaction time, good yields, and simple workup.
- Valizadeh, Hassan,Mahmoodian, Manzar,Gholipour, Hamid
-
-
Read Online
- One-Pot Synthesis of 3-Carboxycoumarins via Consecutive Knoevenagel and Pinner Reactions in Water
-
Chloro-, hydroxy-, methoxy-, and tert-butyl-substituted 3-carboxycoumarins have been prepared by one-pot procedure by reaction of suitably substituted salicylaldehydes with malononitrile in water. The over-all yields are high and the protocol does not require organic solvents.
- Fringuelli, Francesco,Piermatti, Oriana,Pizzo, Ferdinando
-
-
Read Online
- One-Pot Green Synthesis of 2-Oxo-2H-chromene-3-carbonitriles Using Dual-Frequency Ultrasonication
-
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.
-
p. 1508 - 1512
(2021/10/26)
-
- Coumarin derivatives act as novel inhibitors of human dipeptidyl peptidase III: Combined in vitro and in silico study
-
Dipeptidyl peptidase III (DPP III), a zinc-dependent exopeptidase, is a member of the metalloproteinase family M49 with distribution detected in almost all forms of life. Although the physiological role of human DPP III (hDPP III) is not yet fully elucida
- ?ubari?, Domagoj,Agi?, Dejan,Be?lo, Drago,Kara?i?, Zrinka,Karna?, Maja,Lisjak, Miroslav,Lon?ari?, Melita,Molnar, Maja,Popovi?, Boris M.,Rastija, Vesna,Tomi?, Sanja
-
-
- FeCl3-catalyzed cascade reaction: An efficient approach to functionalized coumarin derivatives
-
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
-
supporting information
p. 1507 - 1514
(2014/05/20)
-
- Synthesis of 3-cyano and 3-cyano-4-methyl-coumarins using phase transfer catalysis
-
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
-
p. 1307 - 1308
(2007/10/03)
-
- Synthesis of new iminocoumarins and their transformations into N-chloro and hydrazono compounds
-
The Knoevenagel reaction between 2-hydroxybenzaldehydes and active methylene compounds (malononitrile and ethyl cyanoacetate) produces iminocoumarins and/or coumarins. In order to study the reactivity of the prepared iminocoumarins, chlorination and reaction with N-nucleophiles were studied.
- Volmajer, Julija,Toplak, Renata,Leban, Ivan,Le Marechal, Alenka Majcen
-
p. 7012 - 7021
(2007/10/03)
-
- Conversion of coumarins accompanied by opening and recyclization of the lactone ring. 1. Study of the reaction of 3-ethoxycarbonyl(3-acyl)coumarins with cyanoacetylhydrazine and its derivatives
-
A stepwise sequence for the interaction of 3-ethoxycarbonyl(acyl)coumarins with cyanoacetylhydrazine, its N-acetyl and N-isopropylidene derivatives, leading to the formation of 3-cyanocoumarins, is proposed and demonstrated. It was established that the 3-cyanocoumarins formed are also able to participate in further conversions by a type of Michael reaction.
- Nemeryuk,Dimitrova,Anisimova,Sedov,Solov'eva,Traven
-
p. 1454 - 1465
(2007/10/03)
-
- Simple and efficient one-pot preparation of 3-substituted coumarins in water
-
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
-
p. 1257 - 1266
(2007/10/03)
-