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.
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.
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
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.
