20451-53-0Relevant articles and documents
Oxidation of aryl vinyl sulfides in the Butooh-Ti(OPri)4-(R,R)-diethyl tartrate system
Shainyan,Danilevich
, p. 1825 - 1827 (1998)
Oxidation of aryl vinyl sulfides into aryl vinyl sulfoxides in the ButOOH-Ti(OPri)4-(R, R)-diethyl tartrate system was studied. The process afforded low optical yields (no more than 5%). A model of the oxidation was proposed that allows interpreting the dependence of the reaction enantioselectivity on the structure of a substrate.
Accelerated Oxidation of Organic Sulfides by Microdroplet Chemistry
Li, Jia,Liu, Chengyuan,Chen, Hao,Zare, Richard N.
, p. 5011 - 5015 (2021/04/02)
We report the rapid oxidation of organic sulfides to sulfoxides by means of microdroplet chemistry at room temperature using a spray solution containing an organic sulfide dissolved in water/methanol, dilute (11%-14%) sodium hypochlorite (NaClO), and 5% chloroauric acid (HAuCl4). Ultrasonic nebulization, easy ambient sonic-spray ionization, or electrosonic spray ionization serves as the microdroplet source. High-resolution mass spectrometry was used as an online detector, and nuclear magnetic resonance was used as an offline detector. We found that the sulfoxide yields vary between 66 and 95%, the highest rate of product formation is 195 mg/min for benzyl phenyl sulfoxide, and the time required is a few minutes, which is much less than that required for the conventional means of achieving this chemical transformation. We also applied this microdroplet method to protein fingerprinting. We found that protein sequences containing methionine can be quickly oxidized, providing useful information for protein structure determinations.
Accessing Enantiopure Epoxides and Sulfoxides: Related Flavin-Dependent Monooxygenases Provide Reversed Enantioselectivity
Heine, Thomas,Scholtissek, Anika,Hofmann, Sarah,Koch, Rainhard,Tischler, Dirk
, p. 199 - 209 (2019/11/13)
Enantiopure organic compounds are of major importance for the chemical and pharmaceutical industry. Flavin-dependent group E monooxygenases, composed of monooxygenase and reductase, are known to perform epoxidation of substituted alkenes as well as sulfoxidation in a regio- and enantioselective fashion. Group E is divided into styrene monooxygenases (SMO) and indole monooxygenases (IMO). Hitherto mainly SMOs have been characterized. In this study, we assayed 31 monooxygenases from both types, while 23 of which showed activity. They almost exclusively produced (S)-styrene oxide at high enantiomeric excess with maximum activities of 0.73 μmol min?1 mg?1 (kcat=0.54 s?1). In case of sulfoxidation, we found that the enantioselectivity is contrary between both types. IMOs preferably produce the (S)-enantiomer while SMOs have a tendency to produce the (R)-enantiomer. Sequence analysis and molecular docking of substrates allowed identifying fingerprint motives: SMO N46-V48-H50-Y73-H76-S96 and IMO S46-Q48-M50-V/I73-I76-A96. These form an essential part of the active site while the loop (AS44-51) interacts with the co-substrate and other amino acids direct the substrate. The motives clearly distinguish group E monooxygenases and define the enantioselectivity and thus direct biotechnological applications. Two-hour biotransformations with several sulfides in conjunction with upscale experiments (10 and 100 mg scale) resulted in the identification of promising candidates for the realization of biocatalytic processes.