22966-16-1Relevant articles and documents
C3 amino-substituted chalcone derivative with selective adenosine rA1 receptor affinity in the micromolar range
Janse van Rensburg, Helena D.,Legoabe, Lesetja J.,Terre’Blanche, Gisella
, p. 1581 - 1605 (2020/11/20)
Abstract: To identify novel adenosine receptor (AR) ligands based on the chalcone scaffold, herein the synthesis, characterization and in vitro and in silico evaluation of 33 chalcones (15–36 and 37–41) and structurally related compounds (42–47) are reported. These compounds were characterized by radioligand binding and GTP shift assays to determine the degree and type of binding affinity, respectively, against rat (r) A1 and A2A ARs. The chalcone derivatives 24, 29, 37 and 38 possessed selective A1 affinity below 10?μM, and thus, are the most active compounds of the present series; compound 38 was the most potent selective A1 AR antagonist (Ki (r) = 1.6?μM). The structure–affinity relationships (SAR) revealed that the NH2-group at position C3 of ring A of the chalcone scaffold played a key role in affinity, and also, the Br-atom at position C3′ on benzylidene ring B. Upon in vitro and in silico evaluation, the novel C3 amino-substituted chalcone derivative 38—that contains an α,?-unsaturated carbonyl system and easily allows structural modification—may possibly be a synthon in future drug discovery. Graphic abstract: C3 amino-substituted chalcone derivative (38) with C3′ Br substitution on benzylidene ring B possesses selective adenosine rA1 receptor affinity in micromolar range.[Figure not available: see fulltext.]
Biocatalytic green alternative to existing hazardous reaction media: Synthesis of chalcone and flavone derivatives via the Claisen-Schmidt reaction at room temperature
Tamuli, Kashyap J.,Sahoo, Ranjan K.,Bordoloi, Manobjyoti
supporting information, p. 20956 - 20965 (2020/12/31)
Owing to the increasing amount of waste materials around the globe, the conversion of waste or secondary by-products to value-added products for various applications has gained significant interest. Herein, two novel agro-food waste products, Musa sp. 'Malbhog' peel ash (MMPA) and Musa Champa Hort. ex Hook. F. peel ash (MCPA) are used as catalysts to promote an inexpensive, efficient and eco-friendly carbon-carbon bond forming crossed aldol reaction at room temperature in solvent free conditions. Furthermore, the resulting products were subjected to reactions with these promoters in an oxygen atmosphere and led to the formation of novel flavone derivatives. Moreover, the used catalysts were properly characterized using different sophisticated analytical techniques such as Fourier-transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), Brunauer-Emmett-Teller analysis (BET), Raman spectroscopy, scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDS), transition electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) along with element detection using atomic absorption spectroscopy and ion chromatographic methods. These two approaches are metal free, as well as being devoid of any extra additives, co-catalysts, harsh conditions, the use of column chromatography for purification and result in a higher yield of the product within a short space of time. The catalytic abilities of the promoter were also examined to synthesize important bioactive molecules such as butein and apigenin at room temperature. With gram scale synthesis of the chalcone derivatives, the used catalysts (MMPA and MCPA) were further reused for five cycles and did not demonstrate any loss in catalytic activity.
A general approach to the synthesis of substituted isoxazolo[4,3-c] quinolines via chalcones
Madapa, Sudharshan,Sridhar, Divya,Yadav, Gaya P.,Maulik, Prakas R.,Batra, Sanjay
, p. 4343 - 4351 (2008/04/13)
A general and practical approach to the synthesis of substituted isoxazolo[4,3-c]quinolines from the substituted isoxazolines obtained by 1,3-dipolar cycloadditions between 2-nitrobenzonitrile oxide and chalcones is described. SnCl2·2H2O-mediated reduction of the nitro group, followed by intramolecular cyclization involving the amino and the keto groups in these substrates, furnished mixtures of isoxazolo[4,3-c] quinolines and 3,5-dihydroisoxazolo[4,3-c]-quinolines. In contrast, the reduction of these substrates with Fe/AcOH unexpectedly yielded 3-benzoylquinolin-4-yl-amine derivatives. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Mechanochemical aminochlorination of electron-deficient olefins with chloramine-T promoted by (diacetoxyiodo)benzene
Wang, Guan-Wu,Wu, Xue-Liang
, p. 1977 - 1982 (2008/09/17)
A direct and convenient procedure for the solvent-free mechanochemical aminochlorination of electron-deficient olefins promoted by (diacetoxyiodo) benzene [PhI(OAc)2] was described using commercially available and cheap chloramine-T as a nitrogen and chlorine source. The vicinal chloramine derivatives were obtained in high regio- and stereoselectivity with good yields. PhI(OAc)2 was superior to metal salts for the aminochlorination of electron-deficient olefins.
A new and efficient one-pot solid-supported synthesis of 1,2,4,6-tetraaryl-1,4-dihydropyridines
Verma, Anil K.,Koul, Summon,Razdan, Tej K.,Kapoor, Kamal K.
, p. 1064 - 1073 (2007/10/03)
1,2,4,6-Tetraaryl-1,4-dihydropyridines were obtained by the one-pot reaction of chalcones and substituted anilines on the surface of Bi(III)nitrate-Al2O3. The reaction seems to proceed via β-oxygenation of Bi(III) enolised chalcones followed by Michael addition and heteroannulation with simultaneous retro aldol disproportionation. The presence of the ring-activating groups at ortho and para positions in the aniline seems to be essential for the reaction.
Superacid-Catalyzed Reactions of Cinnamic Acids and the Role of Superelectrophiles
Rendy, Rendy,Zhang, Yun,McElrea, Aaron,Gomez, Alma,Klumpp, Douglas A.
, p. 2340 - 2347 (2007/10/03)
The chemistry of cinnamic acids and related compounds has been studied. In superacid-catalyzed reactions with arenes, two competing reaction mechanisms are proposed. Both mechanisms involve the formation of dicationic intermediates (superelectrophiles), and the reactions can lead to either chalcone-type products or indanone products. The direct observation of a dicationic species (by low-temperature 13C NMR) is reported. We provide clear evidence that protonated carboxylic acid groups (or the corresponding acyl cation) can enhance the reactivity of an adjacent electrophilic center. Triflic acid is also found to be an effective acid catalyst for the direct synthesis of some electron-deficient chalcones and heterocyclic chalcones from cinnnamic acids.
Efficient and Clean Aldol Condensation Catalyzed by Sodium Carbonate in Water
Zhang, Ze,Dong, Ya-Wei,Wang, Guan-Wu
, p. 966 - 967 (2007/10/03)
Efficient and environmentally friendly synthesis of chalcone and azachalcone was performed by aldol condensation of aldehydes with ketones in pure water catalyzed by sodium carbonate. In this convenient methodology, side reactions were avoided and thus high yields were achieved.
The kinetics and mechanism of the reaction of trimethyl phosphite with benzylideneacetophenones
Petnehazy, Imre,Clementis, Gyoergy,Jaszay, Zsuzsa M.,Toeke, Laszlo,Hall, C. Dennis
, p. 2279 - 2284 (2007/10/03)
The kinetics and mechanism of the equilibrium reaction of benzylideneacetophenones 4 with trimethyl phosphite (TMP) to yield, 2,2,2-trimethoxy-2,3-dihydro-1,2λ5-oxaphospholes 5 are reported. The second-order rate constants for the formation of 5 were determined using a polarographic method and the rate constants for the decomposition reaction were calculated from the equilibrium constants. The linear Hammett plots in some cases and the curved ones in others indicate that the rate-determining step depends on the character of the ring substituants in 4 and 5. A thermodynamic study of the forward reaction showed a relatively small enthalpy and a large negative entropy of activation in agreement with the existence of a strongly polarised and/or crowded structure in the transition state. The proposed mechanism, in cases where electron-donating substituents (Y) or hydrogen are on the aromatic ring next to the carbonyl carbon or where electron-donating substituents (X) are on the aromatic ring next to the double bond, involves nucleophilic attack of phosphite on the carbonyl carbon atom in the rate-limiting step to form intermediate I2 followed by a ring closure to an oxaphosphirane I2 and ring enlargement to the oxaphospholene 5. The use of electron-withdrawing substituents (both for X and Y) results in a change in the reaction pathway in which phosphite attacks the carbon atom β to the carbonyl group in the rate-limiting step followed by a fast ring closure of I3 to oxaphospholene 5.
