55685-62-6Relevant articles and documents
Synthesis of cyclic sulfites from epoxides and sulfur dioxide with silica-immobilized homogeneous catalysts
Takenaka, Yasumasa,Kiyosu, Takahiro,Mori, Goro,Choi, Jun-Chul,Fukaya, Norihisa,Sakakura, Toshiyasu,Yasuda, Hiroyuki
, p. 194 - 199 (2012)
Quaternary ammonium- and amino-functionalized silica catalysts have been prepared for the selective synthesis of cyclic sulfites from epoxides and sulfur dioxide, demonstrating the effects of immobilizing the homogeneous catalysts on silica. The cycloaddition of sulfur dioxide to various epoxides was conducted under solvent-free conditions at 100 °C. The quaternary ammonium- and amino-functionalized silica catalysts produced cyclic sulfites in high yields (79-96 %) that are comparable to those produced by the homogeneous catalysts. The functionalized silica catalysts could be separated from the product solution by filtration, thereby avoiding the catalytic decomposition of the cyclic sulfite products upon distillation of the product solution. Heterogenization of a homogeneous catalyst by immobilization can, therefore, improve the efficiency of the purification of crude reaction products. Despite a decrease in catalytic activity after each recycling step, the heterogeneous pyridine-functionalized silica catalyst provided high yields after as many as five recycling processes. Immobilized for crimes of pyrolysis: Quaternary ammonium- and amino-functionalized silica catalysts promote the cycloaddition of sulfur dioxide to epoxides to produce cyclic sulfites in high yields (79-96 %) that are comparable to those with the homogeneous catalysts. Separation of the functionalized silica catalyst from the product solution by filtration avoids pyrolysis of the cyclic sulfites during purification by distillation. Copyright
Reactions of 4-chloromethyl-1,3,2-dioxathiolane 2-oxides with sodium phenoxide. A reinvestigation
Bredikhina, Z. A.,Pashagin, A. V.,Bredikhin, A. A.
, p. 1753 - 1756 (2007/10/03)
The reactions of 4-chloromethyl-1,3,2-dioxathiolane 2-oxides with PhONa in EtOH are accompanied by ring opening under the action of the ethoxide ion rather than leading to a rearrangement of the starting molecule as has been assumed previously. Under conditions precluding competition with other nucleophiles, the phenoxide anion smoothly replaces the chlorine atom in chloromethyl-substituted cyclic sulfites.
