Seleninic acid
A seleninic acid is an organoselenium compound and an oxoacid with the general formula RSeO2H, where R ≠ H. Its structure is R−Se(=O)−OH. It is a member of the family of organoselenium oxoacids, which also includes selenenic acids and selenonic acids, which are R−Se−OH and R−Se(=O)2−OH, respectively. The parent member of this family of compounds is methaneseleninic acid (CH3−Se(=O)−OH), also known as methylseleninic acid or "MSA".
Reactions and applications in synthesis
[edit]Seleninic acids (particularly areneseleninic acids) are useful catalysts for hydrogen peroxide epoxidations, Baeyer–Villiger oxidations, oxidations of thioethers, etc.; peroxyseleninic acids (R−Se(=O)−OOH) are thought to be the active oxidants.[1][2][3]
Structure, bonding, properties
[edit]Methaneseleninic acid has been characterized by X-ray crystallography.[4] The configuration about the selenium atom is pyramidal, with Se-C = 1.925(8) Å, Se-O = 1.672(7) Å, Se-OH = 1.756(7) Å, the angle OSeO = 103.0(3)°, the angle HO-Se-C = 93.5(3)°, and the angle OSeC = 101.4(3)°. The structure is isomorphous to that of methanesulfinic acid [5]
Benzeneseleninic acid (C6H5−Se(=O)−OH) had been previously characterized by X-ray methods[6] and its optical resolution reported.[7]
References
[edit]- ^ Ten Brink, Gerd-Jan; Fernandes, Bruno C. M.; Van Vliet, Michiel C. A.; Arends, Isabel W. C. E.; Sheldon, Roger A. (2001). "Selenium catalysed oxidations with aqueous hydrogen peroxide. Part I: Epoxidation reactions in homogeneous solution". Journal of the Chemical Society, Perkin Transactions 1 (3): 224–228. doi:10.1039/b008198l.
- ^ Ten Brink, Gerd-Jan; Vis, Jan-Martijn; Arends, Isabel W. C. E.; Sheldon, Roger A. (2001). "Selenium-Catalyzed Oxidations with Aqueous Hydrogen Peroxide. 2. Baeyer−Villiger Reactions in Homogeneous Solution1". The Journal of Organic Chemistry. 66 (7): 2429–2433. doi:10.1021/jo0057710. PMID 11281784.
- ^ Mercier, Eric A.; Smith, Chris D.; Parvez, Masood; Back, Thomas G. (2012). "Cyclic Seleninate Esters as Catalysts for the Oxidation of Sulfides to Sulfoxides, Epoxidation of Alkenes, and Conversion of Enamines to α-Hydroxyketones". The Journal of Organic Chemistry. 77 (7): 3508–3517. doi:10.1021/jo300313v. PMID 22432805.
- ^ Block, Eric; Birringer, Marc; Jiang, Weiqin; Nakahodo, Tsukasa; Thompson, Henry J.; Toscano, Paul J.; Uzar, Horst; Zhang, Xing; Zhu, Zongjian (2001). "Allium Chemistry: Synthesis, Natural Occurrence, Biological Activity, and Chemistry of Se -Alk(en)ylselenocysteines and Their γ-Glutamyl Derivatives and Oxidation Products". Journal of Agricultural and Food Chemistry. 49 (1): 458–470. doi:10.1021/jf001097b. PMID 11305255.
- ^ Seff, K.; Heidner, E. G.; Meyers, M.; Trueblood, K. N. "The crystal and molecular structure of methanesulfinic acid." Acta Crystallographica Section B 1969, 25, 350–354.
- ^ Bryden, J. H.; McCullough, J. D. (1954). "The crystal structure of benzeneseleninic acid". Acta Crystallographica. 7 (12): 833–838. Bibcode:1954AcCry...7..833B. doi:10.1107/S0365110X54002551.
- ^ Shimizu, Toshio; Watanabe, Itaru; Kamigata, Nobumasa (2001). "Optically Active Seleninic Acids: Optical Resolution and Stability". Angewandte Chemie International Edition. 40 (13): 2460–2462. doi:10.1002/1521-3773(20010702)40:13<2460::AID-ANIE2460>3.0.CO;2-Q. PMID 11443664.