2-Iodylphenol Ethers: Preparation, X-ray Crystal Structure, and Reactivity of New Hypervalent Iodine(V) Oxidizing Reagents
作者:Alexey Y. Koposov、Rashad R. Karimov、Ivan M. Geraskin、Victor N. Nemykin、Viktor V. Zhdankin
DOI:10.1021/jo0614947
日期:2006.10.1
2-Iodylphenol ethers were prepared by the dimethyldioxirane oxidation of the corresponding 2-iodophenol ethers and isolated as chemically stable, microcrystalline products. Single-crystal X-ray diffraction analysis of 1-iodyl-2-isopropoxybenzene 8c and 1-iodyl-2-butoxybenzene 8d revealed pseudopolymeric arrangements in the solid state formed by intermolecular interactions between IO2 groups of different
Selective Synthesis of Sulfoxides and Sulfones by Methyltrioxorhenium-Catalyzed Oxidation of Sulfides with Hydrogen Peroxide
作者:Shigekazu Yamazaki
DOI:10.1246/bcsj.69.2955
日期:1996.10
Methyltrioxorhenium-catalyzed oxidation of sulfides with hydrogenperoxide in ethanol has been found to be an efficient catalytic system for the selective formation of sulfoxides and sulfones. The oxidation using an equimolar amount of hydrogenperoxide afforded sulfoxides in excellent yield, and the use of two molar amounts of hydrogenperoxide gave sulfones quantitatively. Strongly deactivated sulfide, bis(4-nitrophenyl)
A Mild, Inexpensive, and Convenient Synthesis of Sulfoxides by the Oxidation of Sulfides with Calcium Hypochlorite and Moist Alumina
作者:Masao Hirano、Sigetaka Yakabe、Shikiko Itoh、James H. Clark、Takashi Morimotoa
DOI:10.1055/s-1997-1330
日期:1997.10
The dichloromethane-alumina biphasic system is a simple and effective reagent for the selective oxidation of sulfides to the sulfoxides with calcium hypochlorite.
The selenium-containing dinuclear peroxotungstate, [(n-C4H9)4N]2[SeO4WO(O2)2}2] (I), acts as a homogeneous catalyst for the selective oxidation of various kinds of cyclic mono- and disulfides with 30% aqueous H2O2. The cyclic disulfides were selectively oxidized to the corresponding monosulfoxides with one equivalent of H2O2 with respect to the sulfides. In the presence of two equivalents of H2O2, the oxidation of dibenzothiophene gave the corresponding sulfone in 98% yield under the mild conditions. The negative Hammett Ï value (â0.62) for the competitive oxidation of p-substituted thioanisoles and the low XSO (XSO = (nucleophilic oxidation)/(total oxidation)) value of 0.14 for the I-catalyzed oxidation of thianthrene 5-oxide (SSO) revealed that I is a strong electrophilic oxidant. The reactivities of the di- and tetranuclear peroxotungstates with XO4nâ ligands (X = Se(VI), As(V), P(V), S(VI), and Si(IV)) were strongly dependent on the kinds of hetero atoms. The reaction rates for the sulfoxidation decreased with an increase in the XSO values and a peroxotungstate with a stronger electrophilicity was more active for the sulfoxidation. The kinetic and mechanistic investigations showed that the electrophilic attack of the peroxo oxygen at the sulfur atom is a key step in the sulfoxidation. The computational investigation supported the high chemoselectivitiy for the sulfoxidation of diallyl sulfide.
An environmentally benign and selective electrochemical oxidation of sulfides and thiols in a continuous-flow microreactor
作者:Gabriele Laudadio、Natan J. W. Straathof、Menno D. Lanting、Benny Knoops、Volker Hessel、Timothy Noël
DOI:10.1039/c7gc01973d
日期:——
A practical and environmentally benign electrochemical oxidation of thioethers and thiols in a commercially-available continuous-flow microreactor is presented. Water is used as the source of oxygen to enable the oxidation process. The oxidation reaction utilizes the same reagents in all scenarios and the selectivity is solely governed by the applied potential. The procedure exhibits a broad scope