Home >

news Help

Publication Information


Title
Japanese:Epoxidation of Alkenes with Hydrogen Peroxide Catalyzed by Selenium-Containing Dinuclear Peroxotungstate and Kinetic, Spectroscopic, and Theoretical Investigation of the Mechanism. 
English:Epoxidation of Alkenes with Hydrogen Peroxide Catalyzed by Selenium-Containing Dinuclear Peroxotungstate and Kinetic, Spectroscopic, and Theoretical Investigation of the Mechanism. 
Author
Japanese: Keigo Kamata, Ryo Ishimoto, Tomohisa Hirano, Shinjiro Kuzuya, Kazuhiro Uehara, Noritaka. Mizuno.  
English: Keigo Kamata, Ryo Ishimoto, Tomohisa Hirano, Shinjiro Kuzuya, Kazuhiro Uehara, Noritaka. Mizuno.  
Language English 
Journal/Book name
Japanese:Inorganic Chemistry 
English:Inorganic Chemistry 
Volume, Number, Page Vol. 49    No. 5    pp. 2471-2478
Published date 2010 
Publisher
Japanese:American Chemical Society 
English:American Chemical Society 
Conference name
Japanese: 
English: 
Conference site
Japanese: 
English: 
DOI https://doi.org/10.1021/ic902381b
Abstract The dinuclear peroxotungstate with a SeO42- ligand, (TBA)2[SeO4{WO(O2)2}2] (I; TBA = [(n-C4H9)4N]+), could act as an efficient homogeneous catalyst for the selective oxidn. of various kinds of org. substances such as olefins, alcs., and amines with H2O2 as the sole oxidant. The turnover frequency (TOF) was as high as 210 h-1 for the epoxidn. of cyclohexene catalyzed by I with H2O2. The catalyst was easily recovered and reused with maintenance of the catalytic performance. The SeO42- ligand in I played an important role in controlling the Lewis acidity of the peroxotungstates, which significantly affects their electrophilic oxygen-transfer reactivity. Several kinetic and spectroscopic results showed that the present catalytic epoxidn. included the following two steps: (i) formation of the subsequent peroxo species [SeWmOn]o- (II; m = 1 and 2) by the reaction of I with an olefin and (ii) regeneration of I by the reaction of II with H2O2. Compd. I was the dominant species under steady-state turnover conditions. The reaction rate for the catalytic epoxidn. showed a first-order dependence on the concns. of olefin and I and a zero-order dependence on the concn. of H2O2. The rate of the stoichiometric epoxidn. with I agreed well with that of the catalytic epoxidn. with H2O2 by I. All of these kinetic and spectroscopic results indicate that oxygen transfer from I to the C-C double bond is the rate-detg. step. The computational studies support that the oxygen-transfer step is the rate-detg. step. [on SciFinder(R)]

©2007 Tokyo Institute of Technology All rights reserved.