4521-31-7Relevant articles and documents
Kinetics and mechanism of hydration of o-thioquinone methide in aqueous solution. Rate-determining protonation of sulfur
Chiang, Yvonne,Kresge, A. Jerry,Sadovski, Oleg,Zhan, Hao-Qiang
, p. 1643 - 1646 (2005)
(Chemical Equation Presented) o-Thioquinone methide, 2, was generated in aqueous solution by flash photolysis of benzothiete, 1, and rates of hydration of this quinone methide to o-mercaptobenzyl alcohol, 3, were measured in perchloric acid solutions, using H2O and D2O as the solvent, and also in acetic acid and tris(hydroxymethyl)methylammonium ion buffers, using H2O as the solvent. The rate profiles constructed from these data show hydronium-ion-catalyzed and uncatalyzed hydration reaction regions, just like the rate profiles based on literature data for hydration of the oxygen analogue, o-quinone methide, of the presently examined substrate. Solvent isotope effects on hydronium-ion catalysis of hydration for the two substrates, however, are quite different: kH/kD = 0.42 for the oxygen quinone methide, whereas kH/kD = 1.66 for the sulfur substrate. The inverse nature (kH/kD a preequilibrium proton-transfer reaction mechanism, with protonation of the substrate on its oxygen atom being fast and reversible and capture of the benzyl-type carbocationic intermediate so formed being rate-determining. The normal direction (kH/kD > 1) of the isotope effect in the sulfur system, on the other hand, suggests that protonation of the substrate on its sulfur atom is in this case rate-determining, with carbocation capture a fast following step. A semiquantitative argument supporting this hypothesis is presented.
Synthesis and antiproliferative activity of sulfa-Michael adducts and thiochromenes derived from carbohydrates
Luque-Agudo,Albarrán-Velo,Fernández-Bola?os,López,Light,Padrón,Lagunes,Román,Serrano,Gil
, p. 3154 - 3162 (2017)
The Michael addition reactions of carbohydrate-derived nitroalkenes with ethyl thioglycolate and 2-mercaptobenzyl alcohol were studied. Reactions were conducted under mild, solvent-free conditions with DABCO as a catalyst, affording the corresponding adducts in good yields. Furthermore, compounds resulting from the addition with 2-mercaptobenzyl alcohol were used as starting materials for the synthesis of chiral 3-nitro-2H-thiochromenes. For some of the compounds synthesized herein, the antioxidant and antiproliferative activities against a panel of human solid tumor cell lines were assayed and compared with those of carbohydrate-nitroalkene substrates.
A cascade deprotonation/intramolecular aldol reaction of α-carbonyl sulfonium ylides with 2-mercaptoindole-3-carbaldehydes and 2-mercaptobenzaldehydes to access thieno[2,3-b]indoles and benzothiophenes
Yang, Lei,Zhou, Shun,Zhao, Jian-Qiang,You, Yong,Wang, Zhen-Hua,Zhou, Ming-Qiang,Yuan, Wei-Cheng
supporting information, p. 3678 - 3686 (2021/05/05)
The first catalyst-free cascade deprotonation/intramolecular aldol reaction of α-carbonyl sulfonium ylides with 2-mercaptoindole-3-carbaldehydes and 2-mercaptobenzaldehydes was developed. A series of thieno[2,3-b]indoles and benzothiophenes were smoothly obtained in high to excellent yields. The salient features of the protocol include catalyst-free conditions, an environment-friendly solvent, broad substrate scope, and large-scale synthesis.
DEPALMITOYLATING COMPOSITIONS AND THE USE THEREOF
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Paragraph 0359; 0369-0370, (2021/02/19)
Disclosed herein, inter alia, are depalmitoylating compounds, compositions, and methods of use thereof.
Visible-light induced photo-click and release strategy between monoarylsydnone and phenoxylfumarate
Li, Baolin,Liu, Hui,Shen, Xin,Xie, Xinyu,Yu, Zhipeng,Zhao, Xiaohu,Zheng, Tingting,Zheng, Yuanqin
supporting information, p. 8135 - 8138 (2021/08/23)
We report a visible-light induced photo-click and release platform between monoarylsydnone (MASyd) and phenoxylfumarates. The pyrazoline produced by the cycloaddition undergoes a photo-aromatization to form a fluorescent pyrazole. Meanwhile, the photo-aro
Thiophenol-formaldehyde triazole causes apoptosis induction in ovary cancer cells and prevents tumor growth formation in mice model
Jia, Yan,Si, Lihui,Lin, Ruixin,Jin, Hongjuan,Jian, Wenwen,Yu, Qing,Yang, Shuli
, p. 62 - 70 (2019/04/04)
In the present study a library of thiophenol-formaldehyde-triazole (TFT) derivatives was synthesized and screened against CAOV3, CAOV4 and ES-2 ovary cancer cell lines. Initial screening revealed that five-compounds 5a, 5b, 5j, 5h and 5i inhibited the viability of tested cell lines. Analysis of apoptosis revealed that increase in compound 5a (most active) concentration from 0.25 to 2.0 μM enhanced apoptotic cell proportion. Transwell assay showed reduction in invasive potential of CAOV3 cells on treatment with compound 5a. In wound healing assay increasing the concentration of compound 5a from 0.5 to 2.0 μM caused a significant (P 0.05) decrease in the migration potential. Western blotting showed that compound 5a treatment markedly decreased the level of matrix metalloproteinase (MMP)-2 and ?9 in CAOV3 cells. Treatment of CAOV3 cells with compound 5a caused a marked decrease in Focal Adhesion Kinase (FAK) activation. Tumor growth was inhibited in the compound 5a treated mice markedly than those of untreated group. The tumor metastasis to liver, intestine, spleen and peritoneal cavity was markedly decreased in mice treated with 10 mg/kg dose of compound 5a. Examination of Von Willebrand factor (vWF) expression in liver, intestinal and pulmonary lesions showed a marked decrease in the compound 5a-treated mice. The infiltration of macrophages in the metastatic lesions showed a significant decrease in compound 5a-treated mice. In conclusion, the compound 5a inhibited ovary cancer cell viability and induced apoptosis through decrease in expression of vWF and metalloproteinase, suppression of FAK activation and decrease in infiltration of macrophages. The compound 5a therefore can be investigated further for the treatment of ovary cancer.
Silver-Mediated Oxidative Decarboxylative Trifluoromethylthiolation of Coumarin-3-carboxylic Acids
Li, Minghao,Petersen, Jeffrey L.,Hoover, Jessica M.
supporting information, p. 638 - 641 (2017/02/10)
The introduction of trifluoromethylthio groups into organic compounds, in particular heterocycles, is important because of the prevalence of these structures in medicinally and agriculturally relevant molecules. Herein, the silver-mediated oxidative decarboxylative trifluoromethylthiolation of coumarin-3-carboxylic acids is reported. This methodology utilizes existing carboxylic acid functionalities for the direct conversion to CF3S groups and results in a broad scope of 3-trifluoromethylthiolated coumarins, including analogues of natural products, in moderate to excellent yields.
Sulfinato Iron(III) complex for electrocatalytic proton reduction
Cavell, Andrew C.,Hartley, Carolyn L.,Liu, Dan,Tribble, Connor S.,McNamara, William R.
, p. 3325 - 3330 (2015/04/14)
We report the first example of a sulfinato Fe(III) complex acting as a highly active electrocatalyst for proton reduction. The sulfinate binds to the metal through oxygen, resulting in a seven-membered chelate ring that is likely hemilabile during catalys
The structural and electrochemical consequences of hydrogenating copper N2S2 Schiff base macrocycles
Trotter, Katherine D.,Taylor, Michelle K.,Forgie, John C.,Reglinski, John,Berlouis, Leonard E.A.,Kennedy, Alan R.,Spickett, Corinne M.,Sowden, Rebecca J.
experimental part, p. 1529 - 1538 (2010/08/05)
A series of cis and trans tetradentate copper macrocyclic complexes, of ring size 14-16, that employ amine and thioether donor groups are reported. Apart from 5,6,15,16-bisbenzo-8,13-diaza-1,4-dithia-cyclohexadecane copper(I) (cis-[Cu(H4Nb
Mechanistic insights into the rhodium-catalyzed intramolecular ketone hydroacylation
Shen, Zengming,Dornan, Peter K.,Khan, Hasan A.,Woo, Tom K.,Dong, Vy M.
supporting information; experimental part, p. 1077 - 1091 (2009/06/28)
[Rh((fl)-DTBM-SEGPHOS)]BF4 catalyzes the intramolecular hydroacylation of ketones to afford seven-membered lactones in large enantiomeric excess. Herein, we present a combined experimental and theoretical study to elucidate the mechanism and origin of selectivity in this C-H bond activation process. Evidence is presented for a mechanistic pathway involving three key steps: (1) rhodium(I) oxidative addition into the aldehyde C-H bond, (2) insertion of the ketone C=O double bond into the rhodium hydride, and (3) C-O bond-forming reductive elimination. Kinetic isotope effects and Hammett plot studies support that ketone insertion isthe turnover-limiting step. Detailed kinetic experiments were performed using both 1,3- bis(diphenylphosphino)propane (dppp) and (R)-DTBM-SEGPH OS as ligands. With dppp, the keto-aldehyde substrate assists in dissociating a dimeric precatalyst 8 and binds an active monomeric catalyst 9. With [Rh((R)-DTBM-SEGPHOS)]BF4, there is no induction period and both substrate and product inhibition are observed. In addition, competitive decarbonylation produces a catalytically inactive rhodium carbonyl species that accumulates over the course of the reaction. Both mechanisms were modeled with a kinetics simulation program, and the models were consistent with the experimental data. Density functional theory calculations were performed to understand more elusive details of this transformation. These simulations support that the ketone insertion step has the highest energy transition state and reveal an unexpected interactionbetween the carbonyl-oxygen lone pair and a Rh d-orbital in this transi tion state structure. Finally, a model based on the calculated transition-state geometry is proposed to rationalize the absolute sense of enantioinduction observed using (R)-DTBM-SEGPHOS as the chiral ligand.
