Summary
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.