108646-71-5Relevant articles and documents
Efficient Metal-Free Aerobic Photooxidation of Sulfides to Sulfoxides Mediated by a Vitamin B2Derivative and Visible Light
Nevesely, Tomá?,Svobodová, Eva,Chudoba, Josef,Sikorski, Marek,Cibulka, Radek
, p. 1654 - 1663 (2016)
We have developed a metal-free process for the aerobic photooxygenation of sulfides to sulfoxides mediated by riboflavin tetraacetate or riboflavin (vitamin B2) photocatalysts and visible light (450 nm) in an acetonitrile-water (85:15 v/v) mixture. The optimised solvent system leads to both singlet-oxygen and electron-transfer pathways in photooxygenation, thus allowing oxidation of electron-poor and electron-rich thioanisoles, dialkyl sulfides and sterically hindered sulfides. Besides having a broad substrate scope, the method has very short reaction times and requires low catalyst loading (down to 0.1 mol%). These properties are due to the high photocatalyst stability and the extremely high quantum yields (1.3 for thioanisole oxygenation). Moreover, the method is chemoselective, producing only sulfoxides without overoxidation to sulfones. Taking into account the broad substrate scope, high selectivity and high efficiency, this method distinguishes itself from those previously reported. Other advantages include easy work-up of the reaction mixture, the availability and biodegradability of the photocatalysts and mild reaction conditions. We demonstrated, on a preparative scale, its practical application in the synthesis of the psychostimulant modafinil, in the selective oxidation of methionine derivatives, and in the detoxification of mustard gas. (Figure presented.).
Oxyhalogen-sulfur chemistry: Kinetics and mechanism of oxidation of N-Acetyl-L-methionine by aqueous iodine and acidified iodate
Chipiso, Kudzanai,Mbiya, Wilbes,Morakinyo, Moshood K.,Simoyi, Reuben H.
, p. 626 - 635 (2014)
The use of N-acetyl-l-methionine (NAM) as a bio-available source for methionine supplementation as well as its ability to reduce the toxicity of acetaminophen poisoning has been reported. Its interaction with the complex physiological matrix, however, has not been thoroughly investigated. This manuscript reports on the kinetics and mechanism of oxidation of NAM by acidic iodate and aqueous iodine. Oxidation of NAM proceeds by a two electron transfer process resulting in formation of a sole product: N-acetyl-l-methionine sulfoxide (NAMS≤O). Data from electrospray ionization mass spectrometry confirmed the product of oxidation as NAMS≤O. The stoichiometry of the reaction was deduced to be IO3- + 3NAM → I- + 3NAMS≤O. In excess iodate, the stoichiometry was deduced to be 2IO 3 + 5NAM+ 2H+ → I2+ 5NAMS≤O + H 2O. The reaction between aqueous iodine and NAM gave a 1:1 stoichiometric ratio: NAM + I2 + H2O → NAMS≤O + 2I- + H+. This reaction was relatively rapid when compared with that between NAM and iodate. It did, however, exhibit some auto-inhibitory effects through the formation of triiodide (I3-) which is a relatively inert electrophile when compared with aqueous iodine. A simple mechanism containing 11 reactions gave a reasonably good fit to the experimental data. CSIRO 2014.
Enantioselective Transfer Hydrogenation of Ketones using a Rhodium Catalyst containing a Methionine Sulphoxide Ligand
Kvintovics, Pal,James, Brian R.,Heil, Balint
, p. 1810 - 1811 (1986)
An in situ rhodium catalyst containing N-acetyl-(S)-methionine (R,S)-sulphoxide, and using propan-2-ol as a source of hydrogen, effects enantioselective hydrogenation of alkyl aryl ketones with up to 75percent enantiomeric excess.
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Morihara,K.
, p. 1787 - 1794 (1964)
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