21487-48-9Relevant academic research and scientific papers
Solution equilibrium, structural and cytotoxicity studies on Ru(η6-p-cymene) and copper complexes of pyrazolyl thiosemicarbazones
D?m?t?r, Orsolya,Kiss, Márton A.,Gál, G. Tamás,May, Nóra V.,Spengler, Gabriella,Nové, Márta,Ga?parovi?, Ana ?ipak,Frank, éva,Enyedy, éva A.
, (2019/11/11)
Solution chemical properties of two bidentate pyrazolyl thiosemicarbazones 2-((3-methyl-1-phenyl-1H-pyrazol-4-yl)methylene)hydrazinecarbothioamide (Me-pyrTSC), 2-((1,3-diphenyl-1H-pyrazol-4-yl)methylene)hydrazinecarbothioamide (Ph-pyrTSC), stability of their Cu(II) and Ru(η6-p-cymene) complexes were characterized in aqueous solution (with 30% DMSO) by the combined use of UV–visible spectrophotometry, 1H NMR spectroscopy and electrospray ionization mass spectrometry in addition to their solid phase isolation. The solid phase structures of Me-pyrTSC?H2O, [Ru(η6-p-cymene)(Me-pyrTSC)Cl]Cl and [Cu(Ph-pyrTSCH?1)2] were determined by single crystal X-ray diffraction. High stability mononuclear Ru(η6-p-cymene) complexes with (N,S) coordination mode are formed in the acidic pH range, and increasing the pH the predominating dinuclear [(Ru(η6-p-cymene))2(L)2]2+ complex with μ2-bridging sulphur donor atoms is formed (where L? is the deprotonated thiosemicarbazone). [CuL]+ and [CuL2] complexes show much higher stability compared to that of complexes of the reference compound benzaldehyde thiosemicarbazone. [CuL2] complexes predominate at neutral pH. Me-pyrTSC and Ph-pyrTSC exhibited moderate cytotoxicity against human colonic adenocarcinoma cell lines (IC50 = 33–76 μM), while their complexation with Ru(η6-p-cymene) (IC50 = 11–24 μM) and especially Cu(II) (IC50 = 3–6 μM) resulted in higher cytotoxicity. Cu(II) complexes of the tested thiosemicarbazones were also cytotoxic in three breast cancer and in a hepatocellular carcinoma cell line. No reactive oxygen species production was detected and the relatively high catalase activity of SUM159 breast cancer cells was decreased upon addition of the ligands and the complexes. In the latter cell line the tested compounds interfered with the glutathione synthesis as they decreased the concentration of this cellular reductant.
Simple and Efficient Ruthenium-Catalyzed Oxidation of Primary Alcohols with Molecular Oxygen
Ray, Ritwika,Chandra, Shubhadeep,Maiti, Debabrata,Lahiri, Goutam Kumar
supporting information, p. 8814 - 8822 (2016/07/06)
Oxidative transformations utilizing molecular oxygen (O2) as the stoichiometric oxidant are of paramount importance in organic synthesis from ecological and economical perspectives. Alcohol oxidation reactions that employ O2are scarce in homogeneous catalysis and the efficacy of such systems has been constrained by limited substrate scope (most involve secondary alcohol oxidation) or practical factors, such as the need for an excess of base or an additive. Catalytic systems employing O2as the “primary” oxidant, in the absence of any additive, are rare. A solution to this longstanding issue is offered by the development of an efficient ruthenium-catalyzed oxidation protocol, which enables smooth oxidation of a wide variety of primary, as well as secondary benzylic, allylic, heterocyclic, and aliphatic, alcohols with molecular oxygen as the primary oxidant and without any base or hydrogen- or electron-transfer agents. Most importantly, a high degree of selectivity during alcohol oxidation has been predicted for complex settings. Preliminary mechanistic studies including18O labeling established the in situ formation of an oxo–ruthenium intermediate as the active catalytic species in the cycle and involvement of a two-electron hydride transfer in the rate-limiting step.
Electronic Structure and Multicatalytic Features of Redox-Active Bis(arylimino)acenaphthene (BIAN)-Derived Ruthenium Complexes
Singha Hazari, Arijit,Ray, Ritwika,Hoque, Md Asmaul,Lahiri, Goutam Kumar
, p. 8160 - 8173 (2016/08/24)
The article examines the newly designed and structurally characterized redox-active BIAN-derived [Ru(trpy)(R-BIAN)Cl]ClO4 ([1a]ClO4-[1c]ClO4), [Ru(trpy)(R-BIAN)(H2O)](ClO4)2 ([3a](ClO4)2-[3c](ClO4)2), and BIAO-derived [Ru(trpy)(BIAO)Cl]ClO4 ([2a]ClO4) (trpy = 2,2′:6′,2′′-terpyridine, R-BIAN = bis(arylimino)acenaphthene (R = H (1a+, 3a2+), 4-OMe (1b+, 3b2+), 4-NO2 (1c+, 3c2+), BIAO = [N-(phenyl)imino]acenapthenone). The experimental (X-ray, 1H NMR, spectroelectrochemistry, EPR) and DFT/TD-DFT calculations of 1an-1cn or 2an collectively establish {RuII-BIAN0} or {RuII-BIAO0} configuration in the native state, metal-based oxidation to {RuIII-BIAN0} or {RuIII-BIAO0}, and successive electron uptake processes by the α-diimine fragment, followed by trpy and naphthalene π-system of BIAN or BIAO, respectively. The impact of the electron-withdrawing NO2 function in the BIAN moiety in 1c+ has been reflected in the five nearby reduction steps within the accessible potential limit of -2 V versus SCE, leading to a fully reduced BIAN4- state in [1c]4-. The aqua derivatives ({RuII-OH2}, 3a2+-3c2+) undergo simultaneous 2e-/2H+ transfer to the corresponding {RuIV-O} state and the catalytic current associated with the RuIV/RuV response probably implies its involvement in the electrocatalytic water oxidation. The aqua derivatives (3a2+-3c2+) are efficient and selective precatalysts in transforming a wide variety of alkenes to corresponding epoxides in the presence of PhI(OAc)2 as an oxidant in CH2Cl2 at 298 K as well as oxidation of primary, secondary, and heterocyclic alcohols with a large substrate scope with H2O2 as the stoichiometric oxidant in CH3CN at 343 K. The involvement of the {RuIV-O} intermediate as the active catalyst in both the oxidation processes has been ascertained via a sequence of experimental evidence.
An expedient osmium(vi)/K3Fe(CN)6-mediated selective oxidation of benzylic, allylic and propargylic alcohols
Fernandes, Rodney A.,Bethi, Venkati
, p. 40561 - 40568 (2015/02/18)
A chemoselective osmium(vi) catalyzed oxidation of benzylic, allylic and propargylic alcohols using K3Fe(CN)6as a secondary oxidant is described. This protocol is operationally simple and exhibits excellent chemoselectivity favouring the oxidation of benzylic alcohols over the aliphatic alcohols. A larger scale reaction was also found to be compatible. This journal is
2-(3-Methyl-1-phenyl-1 H-pyrazol-4-yl)-3-phenylthiazolidin-4-ones as potent antioxidant and antidiabetic agent
Sen, Sandip,De, Biplab,Easwari
, p. 6616 - 6622 (2015/02/19)
A series of 2-(3-methyl-1-phenyl-1H-pyrazol-4-yl)-3-phenylthiazolidin-4-ones (7a-7j) were synthesized by intramolecular cyclization of imines (6a-6j) with thioglycolic acid in the presence of acid catalyst. The Schiff bases were obtained upon reaction between electrophilic carbon atom of 3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde (4) and nucleophilic nitrogen atom of substituted aromatic amines. in vitro Antioxidant activity was determined by DPPH redical scavenging assay mehod using ascorbic acid as standard. The antidiabetic activity was carried out by streptazocine induced diabetic method using rosiglitazone as standard drug on wister rats. From the study it were found that 3-(4-chlorophenyl)-2-(3-methyl-1-phenyl-1H-pyrazol-4-yl)thiazolidin-4-one (7a), 3-(4-bromophenyl)-2-(3-methyl-1-phenyl-1H-pyrazol-4-yl)thiazolidin-4-one (7b), 3-(3,4-dichlorophenyl)-2-(3-methyl-1-phenyl-1H-pyrazol-4-yl)thiazolidin-4-one (7d ), 3-(3,4-difluorophenyl)-2-(3-methyl-1-phenyl-1H-pyrazol-4-yl)thiazolidin-4-one (7f) 2-(3-methyl-1-phenyl-1H-pyrazol-4-yl)-3-(4-(trifluoromethyl) phenyl) thiazolidin-4-one (7h), 3-(4-methoxyphenyl)-2-(3-methyl-1-phenyl-1H-pyrazol-4-yl) thiazolidin-4-one (7j) shown more IC50compare to standard. Where as compound 7a, 7b, 7h, 7j show more significant antidiabetic effect against hyperglycemic rats compare to standard drugs at the dose of 5 mg/kg after 21 days of treatment.
Synthesis and antiviral activity of novel pyrazole derivatives containing oxime esters group
Ouyang, Guiping,Chen, Zhuo,Cai, Xue-Jian,Song, Bao-An,Bhadury, Pinaki S.,Yang, Song,Jin, Lin-Hong,Xue, Wei,Hu, De-Yu,Zeng, Song
experimental part, p. 9699 - 9707 (2009/04/11)
Fourteen title compounds, 1-substituted-5-substitutedphenylthio-4-pyrazolaldoxime ester derivatives 4a-4n, were synthesized from the starting material 1-substitutedphenyl-3-methyl-5-substitutedphenylthio-4-pyrazolaldoximes 3 by treatment with acyl chlorid
Research in the Azole Series. Synthesis and 13C NMR Study of Pyrazole-4-carboxaldehydes
Echevarria, Aurea,Elguero, Jose,Meutermans, Wim
, p. 957 - 960 (2007/10/02)
Ten new pyrazoles have been prepared and their 13C nmr chemical shifts compared with those of twelve other pyrazoles, some of them prepared purposely for this study.The chemical shifts are discussed statistically assuming that they are additive.A formyl group in the position 4 of the pyrazole ring produces a large effect on carbon C4 (SCS = 17.3 ppm) and medium effects on carbons C3 (SCS = 1.9 ppm) and C5 (SCS = 3.8 ppm).The azines derived from pyrazole-4-carboxaldehydes are of the E,E-configuration.
