- Synthesis, photophysical and electrochemical properties of novel and highly fluorescent difluoroboron flavanone β-diketonate complexes
-
Difluoroboron β-diketonates complexes are highly luminescent with extensive properties such as their fluorescence both in solution and in solid state and their high molar extinction coefficients. Due to their rich optical properties, these compounds have been studied for their applications in organic electronics such as in self-assembly and applications in biosensors, bio-imaging and optoelectronic devices. The easy and fast synthesis of difluoroboron β-diketonate (BF2dbm) complexes makes their applications even more attractive. Although many different types of difluoroboron β-diketonates complexes have been studied, the cyclic flavanone analogues of these compounds have never been reported in the literature. Therefore, the present work aims to synthesize difluouroboron flavanone β-diketonate complexes, study their photophysical and electrochemical properties and assess their suitability for applications in optoelectronic devices. The synthesis was based on a Baker-Venkataraman reaction which initially provided substituted diketones, which were subsequently reacted with aldehydes to afford the proposed flavanones. The complexation was achieved by reacting flavanones and BF3·Et2O and in total 9 novel compounds were obtained. A representative difluoroboron flavanone complex was subjected to single crystal X-ray diffraction to unequivocally confirm the chemical structure. A stability study indicated only partial degradation of these compounds over a few days in a protic solvent at elevated temperatures. Photophysical studies revealed that the substituent groups and the solvent media significantly influence the electrochemical and photophysical properties of the final compounds, especially the molar absorption coefficient, fluorescence quantum yields, and the band gap. Moreover, the compounds exhibited a single excited-state lifetime in all studied solvents. Computational studies were employed to evaluate ground and excited state properties and carry out DFT and TDDFT level analysis. These studies clarify the role of each state in the experimental absorption spectra as well as the effect of the solvent.
- Paez, Elida Betania Ariza,Curcio, Sergio,Neme, Natália P.,Matos, Matheus J. S.,Correa, Rodrigo S.,Pereira, Fabio Junio,Hilário, Flaviane Francisco,Cazati, Thiago,Taylor, Jason Guy
-
supporting information
p. 14615 - 14631
(2020/10/02)
-
- Trypanocidal activity of flavanone derivatives
-
Chagas disease, also known as American trypanosomiasis, is classified as a neglected disease by the World Health Organization. For clinical treatment, only two drugs have been on the market, Benznidazole and Nifurtimox, both of which are recommended for use in the acute phase but present low cure rates in the chronic phase. Furthermore, strong side effects may result in discontinuation of this treatment. Faced with this situation, we report the synthesis and trypanocidal activity of 3-benzoyl-flavanones. Novel 3-benzoyl-flavanone derivatives were prepared in satisfactory yields in the 3-step synthetic procedure. According to recommended guidelines, the whole cell-based screening methodology was utilized that allowed for the simultaneous use of both parasite forms responsible for human infection. The majority of the tested compounds displayed promising anti-Trypanosoma cruzi activity and the most potent flavanone bearing a nitrofuran moiety was more potent than the reference drug, Benznidazole.
- Andrade, Josimara Souza,Diogo, Gabriela Maciel,Dos Santos, Viviane Martins Rebello,Murta, Silvane Maria Fonseca,Sales, Policarpo Ademar,Taylor, Jason Guy
-
-
- Novel Bifunctionalization of Activated Methylene: Base-Promoted Trifluoromethylthiolation of β-Diketones with Trifluoromethanesulfinyl Chloride
-
A novel bifunctionalization of activated methylene was achieved successfully through the base-promoted trifluoromethylthiolation of β-diketones or β-ketoesters with trifluoromethanesulfinyl chloride. A series of α-trifluoromethylthiolated α-chloro-β-diketones and α-chloro-β-ketoesters were obtained in moderate to good yields under mild conditions. When β-diketones containing a phenyl group with a hydroxyl or amino substituent at the ortho position were used as substrates, intramolecular trifluoromethylthiolation/cyclization reaction took place to give the corresponding cyclic products. Furthermore, the protocol could be extended to perfluoroalkylthiolation with the sodium perfluoroalkanesulfinate/POCl3 system. On the basis of experimental results, plausible mechanisms are proposed.
- Sun, Dong-Wei,Jiang, Min,Liu, Jin-Tao
-
supporting information
p. 10797 - 10802
(2019/07/03)
-
- Rh(III)-Catalyzed Aldehydic C?H Functionalization Reaction between Salicylaldehydes and Sulfoxonium Ylides
-
A novel aldehydic C?H functionalization reaction between salicylaldehydes and sulfoxonium ylides has been developed under rhodium(III) catalysis, affording coupling products in moderate to good yields. A plausible mechanism involving aldehydic C(sp2)?H activation by rhodium(III) and rhodium(III) catalyzed carbene insertion is also proposed. It was also found that the aldehydic C?H functionalization followed by dehydrative cyclization was able to produce flavonoids in one-pot. (Figure presented.).
- Xu, Guo-Dong,Huang, Kenneth L.,Huang, Zhi-Zhen
-
supporting information
p. 3318 - 3323
(2019/06/25)
-
- An Efficient One-Pot Synthesis and Anticancer Activity of 4'-Substituted Flavonoids
-
A number of 4'-substituted (R = H, Me, Cl, F) flavone derivatives is synthesized from 2-hydroxyacetophenones using the modified Baker–Venkataraman reaction. Compound [3-(4-fluorobenzoyl)-5- hydroxy-4'-fluoroflavone] was synthesized for the first time with the yield of 12%. Antiproliferative assays indicate that the synthesized flavones with F substituent at the 4' position demonstrate higher activity than the other flavone derivatives, particularly against HeLa and MCF-7 with the IC50 9.5 and 2.7 μM, respectively.
- Wang,Liu,Zhang
-
p. 1036 - 1041
(2018/07/06)
-
- Discovery and Optimization of Chromeno[2,3-c]pyrrol-9(2H)-ones as Novel Selective and Orally Bioavailable Phosphodiesterase 5 Inhibitors for the Treatment of Pulmonary Arterial Hypertension
-
Phosphodiesterase 5 (PDE5) inhibitors have been used as clinical agents to treat erectile dysfunction and pulmonary arterial hypertension (PAH). Herein, we detail the discovery of a novel series of chromeno[2,3-c]pyrrol-9(2H)-one derivatives as selective and orally bioavailable inhibitors against phosphodiesterase 5. Medicinal chemistry optimization resulted in 2, which exhibits a desirable inhibitory potency of 5.6 nM with remarkable selectivity as well as excellent pharmacokinetic properties and an oral bioavailability of 63.4%. In addition, oral administration of 2 at a dose of 5.0 mg/kg caused better pharmacodynamics effects on both mPAP (mean pulmonary artery pressure) and RVHI (index of right ventricle hypertrophy) than sildenafil citrate at a dose of 10.0 mg/kg. These activities along with its reasonable druglike properties, such as human liver microsomal stability, cytochrome inhibition, hERG inhibition, and pharmacological safety, indicate that 2 is a potential candidate for the treatment of PAH.
- Wu, Deyan,Zhang, Tianhua,Chen, Yiping,Huang, Yadan,Geng, Haiju,Yu, Yanfa,Zhang, Chen,Lai, Zengwei,Wu, Yinuo,Guo, Xiaolei,Chen, Jianwen,Luo, Hai-Bin
-
p. 6622 - 6637
(2017/08/17)
-
- Transition-Metal-Free Photoinduced Intramolecular Annulation of 2,3-Di(hetero)arylchromen-4-one
-
An efficient transition-metal-free photoinduced intracyclization of 4H-chromen-4-ones in EtOH-H2O (7:1, v/v) at ambient temperature for the construction of complicated fused-ring heteroaromatics is established. The reaction proceeds smoothly without requiring any catalysts/additives.
- Han, Jie,Wang, Tao,Liang, Yong,Li, Ying,Li, Chenchen,Wang, Rui,Feng, Siqi,Zhang, Zunting
-
supporting information
p. 3552 - 3555
(2017/07/17)
-
- One-Pot Synthesis of Benzopyran-4-ones with Cancer Preventive and Therapeutic Potential
-
A one-pot synthesis of novel benzopyran-4-ones is described. In a tandem reaction, organobase-catalysed Michael addition of R1COCH2COR2 on chromone-3-carboxylic acid led to decarboxylation and pyran-4-one ring opening of the latter. This was followed by chromone-and/or chromanone ring closure of the resulting Michael adducts when R1 is an ortho-hydroxyaryl group. Antioxidant testing of 14 derivatives identified strong antiradical properties of chromanones 3o-r (2.1-3.1 μmol Trolox equiv./μmol compound in the DPPH assay). Chromanones 3p and 3r and 2-styrylchromone 3k were also most potent in inducing the cytoprotective Keap1-Nrf2 signalling pathway in a reporter gene assay (fivefold induction at concentrations 3 μM). Of the seven compounds evaluated for antiproliferative activities, 3k and 3r were the most active, inhibiting leukaemia K562 cell proliferation by 50 % after 72 h at concentrations of 4.5 and 7.9 μM, whereas normal peripheral blood mononuclear cells were not affected. Chromanones 3p and 3r and 2-styrylchromones 3k potently activate the Nrf2 response in the AREc32 cell line at low micromolar concentrations (C5 3 μM). Compounds 3k and 3r are also the most active in inhibiting cell proliferation by 50 % after 72 h incubation at concentrations of 4.5 and 7.7 μM, whereas normal peripheral blood mononuclear cells were not affected.
- Talhi, Oualid,Brodziak-Jarosz, Lidia,Panning, Jana,Orlikova, Barbora,Zwergel, Clemens,Tzanova, Tzvetomira,Philippot, Stéphanie,Pinto, Diana C. G. A.,Paz, Filipe A. Almeida,Gerhaüser, Clarissa,Dick, Tobias P.,Jacob, Claus,Diederich, Marc,Bagrel, Denyse,Kirsch, Gilbert,Silva, Artur M. S.
-
p. 965 - 975
(2016/03/01)
-
- Synthesis and anti-trypanosoma cruzi activity of diaryldiazepines
-
Chagas disease is a so-called "neglected disease" and endemic to Latin America. Nifurtimox and benznidazole are drugs that have considerable efficacy in the treatment of the acute phase of the disease but cause many significant side effects. Furthermore, in the Chronic Phase its efficiency is reduced and their therapeutic effectiveness is dependent on the type of T. cruzi strain. For this reason, the present work aims to drive basic research towards the discovery of new chemical entities to treat Chagas disease. Differently substituted 5,7-diaryl-2,3-dihydro-1,4-diazepines were synthesized by cyclocondensation of substituted flavones with ethylenediamine and tested as anti-Trypanosoma cruzi candidates. Epimastigotes of the Y strain from T. cruzi were used in this study and the number of parasites was determined in a Neubauer chamber. The most potent diaryldiazepine that reduced epimastigote proliferation exhibited an IC50 value of 0.25 μM, which is significantly more active than benznidazole.
- Menezes, Jlio Csar L.,Vaz, Luana Beatriz A.,De Vieira, Paula Melo Abreu,Fonseca, Ktia Da Silva,Carneiro, Cludia Martins,Taylor, Jason G.
-
-
- Synthesis and modification of light-sensitive 3-acyl-2-hetarylchromones containing bromomethyl group in the acyl fragment
-
A synthesis of photosensitive 3-acyl-2-hetarylchromones containing bromomethyl group in the 3-aroyl fragment and their further modification by the reactions with N-, S- and O-nucleophiles are described. A dependence of spectral properties from the structu
- Semenova,Levchenko,Yarovenko,Krayushkin,Barachevskii,Kobeleva,Valova
-
p. 1761 - 1768
(2013/11/19)
-
- An efficient synthesis of 3-bromoflavones under solvent free conditions using grinding technique
-
Selective bromination of 1-(2-hydroxyphenyl)-3-phenylpropane- 1,3-diones has been carried out with ammonium bromide and ammonium persulphate at room temperature using grinding technique under solvent free conditions to give 2-bromo derivatives which on cyclodehydration with p-toluenesulphonic acid under grinding conditions give 3-bromoflavones. Also, flavones on bromination using above mentioned conditions give 3-bromoflavones directly.
- Jakhar, Komal,Makrandi
-
body text
p. 770 - 773
(2012/06/30)
-
- Structure activity relationship studies of some potent antifungal flavones, 4-thioflavones and 4-iminoflavones
-
A series of flavones, carrying halogens, methoxy and nitro groups at various positions were synthesized by the Baker-Venkataraman rearrangement and were subsequently converted to 4-thioflavones and 4-iminoflavones. The synthesized compounds were evaluated for their in vitro antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glabrata. All synthesized compounds showed significant activity against T. longusus, A. flavus, M. canis and F. Solani but inactive against C. albicans and C. glabrata, respectively. 2-phenyl-4H-1-benzopyran-4-thiones were relatively more active than flavones and 4-iminoflavones. However, some compounds were even more active than standard miconazol and amphotericin B drugs.
- Hasan, Aurangzeb,Mughal,Sadiq
-
scheme or table
p. 4361 - 4364
(2012/09/07)
-
- Synthesis and antibacterial activity of substituted flavones, 4-thioflavones and 4-iminoflavones
-
Synthesis of flavones, 4-thioflavones and 4-iminoflavones was carried out with the substitution of variable halogens, methyl, methoxy and nitro groups in the A, B and AB rings of the respective compounds and we also report here their antibacterial activity. Most of the synthesized compounds were found to be active against Escherichia coli, Bacillus subtilis, Shigella flexnari, Salmonella aureus, Salmonella typhi and Pseudomonas aeruginosa. Activity of 4-thioflavones and 4-iminoflavones was found to be higher than that of their corresponding flavone analogues. Investigated compounds having substituents like F, OMe and NO2 at 4′-position in ring-B exhibited enhanced activity and the presence of electronegative groups in the studied compounds showed a direct relationship to the antibacterial activity.
- Ullah Mughal, Ehsan,Ayaz, Muhammad,Hussain, Zakir,Hasan, Aurangzeb,Sadiq, Amina,Riaz, Muhammad,Malik, Abdul,Hussain, Samreen,Choudhary, M. Iqbal
-
p. 4704 - 4711
(2007/10/03)
-
- Synthesis of 3-alkenyl-2-arylchromones and 2,3-dialkenylchromones via acid-catalysed retro-Michael ring opening of 3-acylchroman-4-ones
-
3-Acylchromones and 3-acylflavones, readily available by acylation of 2′-hydroxydibenzoylmethane with acid anhydrides in the presence of base, undergo efficient conjugate reduction with NaBH4 in pyridine to give the corresponding chroman-4-ones/flavanones in high yields. The reduction is both regio- and chemoselective. Treatment of the chroman-4-ones with MeSO 3H generates the 3-alkenyl-2-arylchromones by a dehydrative rearrangement initiated by retro-Michael cleavage of the pyranone ring. This reduction-rearrangement sequence can be extended to 2-alkyl-3-alkenoylchromones to generate 3-alkenyl-2-styrylchromones, the first examples of 2,3-dialkenylchromones.
- Clarke, David S.,Gabbutt, Christopher D.,Hepworth, John D.,Heron, B. Mark
-
p. 5515 - 5519
(2007/10/03)
-
- Novel flavonoids and their use in cosmetic and dermatological preparations
-
Flavonoids of the formula in which R is one of the radicals of the formula Ia or Ib where R1 is hydrogen or C1- to C4-alkyl, hydroxyl, C1- to C4-alkoxy, phenyloxy or benzyloxy, R2 is hydrogen or C1- to C4-alkyl, R3 is hydrogen, C1- to C4-alkyl, C1- to C4-alkoxy or cyano, R4 is hydrogen, C1- to C4-alkyl or phenyl, n is 0 or 1 and Het is a pyridyl, furyl or methylpyrrolyl radical, with the proviso that when the radical R=Ia and n=0, at most 2 of the radicals R1 to R3 are hydrogen at the same time, and their use in cosmetic and dermatological preparations.
- -
-
-
- A new metal complex promoted system for highly selective synthesis of 4H-chromen-4-ones (chromones)
-
Co(III)(salpr)(OH), a six coordinate cobalt Schiff base complex, promotes the highly selective conversion of 1-(o-hydroxyaryl)-1,3-diketones to 4H-chromen-4-ones under neutral conditions.
- Nishinaga,Ando,Maruyama,Mashino
-
p. 839 - 841
(2007/10/02)
-
- Epoxidation of Flavones by Dimethyldioxirane
-
The synthesis of epoxides 2 by epoxidation of flavones 1 with isolated dimethyldioxirane (as acetone solution) at subambient temperatures is reported.These labile epoxides were isolated and completely characterized by UV, IR, 1H and 13C NMR, MS, and C,H analyses.Warming to room temperature led to rearrangement to afford quantitatively the 3-hydroxyflavones 3b,h,i,n.Treatment of the epoxides 2b,f with methanol led to the 3-hydroxy-2-methoxyflavanones 4b,f, as a mixture of cis and trans isomers.
- Adam, Waldemar,Golsch, Dieter,Hadjiarapoglou, Lazaros
-
p. 7292 - 7297
(2007/10/02)
-
- Reactions of Carbonyl Compounds in Basic Solutions. Part 11. The Baker-Venkataraman Rearrangement
-
The detailed mechanism of the Baker-Venkataraman rearrangement has been studied.The kinetics of the rearrangement of a series of 2-acetylphenyl 3- or 4-substituted benzoates and acetylnaphthyl benzoates catalysed by a basic 'non-nucleophilic' buffer in dimethyl sulphoxide have been measured.Studies of substituent effects, kinetic isotope effects, and acidity function correlations indicate a pathway involving pre-equilibrium formation of the carbanion, followed by rate-determining intramolecular nucleophilic attack.The methanolysis of the 2-acetylphenyl benzoates catalysed by methoxide in methanolic dimethyl sulphoxide has been similary investigated.In this case the pathway appears to involve neighbouring group participation by the ketonic carbonyl group.
- Bowden, Keith,Chehel-Amiran, Mohsen
-
p. 2039 - 2044
(2007/10/02)
-
- 2-(2'-Hydroxyphenyl)-4-aryl-1,5-benzodiazepines as CNS active agents
-
1-Aryl-3(2'-hydroxyphenyl)-propane-1,3-diones (III) have been prepared by the Baker-Venkataraman transformation of the corresponding 2-substituted benzoyloxyacetophenones (II). The aforesaid propane-1,3-diones (III) were condensed with o-phenylene diamine
- Srivastava,Satsangi,Kishore
-
p. 1512 - 1514
(2007/10/02)
-