Of organic sulfides

Electrolysis of organic sulfides in FIF affords a variety of fluorocarbon derivatives ... 

Holland HE (1988) Chiral sulfoxidation by biotransformation of organic sulfides. Chem Rev 88 473-485. 

Sodium chlorite reacts very violently with organic compounds of divalent sulfur, or with free sulfur (which may ignite), even in presence of water. Contact of the chlorite with rubber vulcanised with sulfur or a divalent sulfur compound should therefore be avoided [1]. Application of factorial design techniques to experimental planning gave specific conditions for the safe oxidation of organic sulfides to sulfoxides using sodium chlorite or calcium hypochlorite [2],... 

Clennan, E.L., Zhou, W. and Chan, J. (2002). Mechanistic organic chemistry in a microreactor. Zeolite-controlled photooxidations of organic sulfides. J. Org. Chem. 67, 9368-9378... 

Jensen, F., Greer, A. and Clennan, E.L. (1998). Reaction of organic sulfides with singlet oxygen. A revised mechanism. J. Am. Chem. Soc. 120, 4439 4449... 

Anodic nucleophilic functionalization of an a-carbon turned out to be particularly efficient for the fluorination of organic sulfides. The introduction of one or two fluorine atoms at the a-carbon was reported in several papers for sulfides bearing EWGs = CN, COMe, COPh, CF3, COzEt, CONEt2, PO(OEt)2) (Scheme 18) [75-78], Two systems are mainly used as the supporting electrolyte and fluorine source at a time namely, EtsN-SHF and Etr NF. 

The assistance of some electron-rich groups [94-96], heteroatoms [90, 97, 98] or filled cr-orbitals [99,100] in the oxidation of organic sulfides was studied in a series of papers (Scheme 24). Since the 3p orbitals of sulfur are quite compact compared to those of Se, the mentioned electronic and stereoelectronic effects are rather remarkable. These interactions (discussed in terms of a trans-annular... 

A variety of organic sulfides can be monofluorinated with tetrabutylammonium dihydro-gen trifluoride and 1.3-dibromo-5,5-dimethylhydantoin at the a-position to the sulfur atom.79... 

An isohexide monoester (not specified) has been used as an adjuvant for the synthesis of organic sulfides and oligosulfides.221... 

Modified Waksman s medium was prepared in a Fernbach culture flask. An amount of organic sulfide normalized to an equivalent sulfur content of the standard medium (10 g/1.) was added followed by an emulsifier. The medium was then autoclaved for 30 min at 15 psi (121°C), or, as with the polysulfide and elemental sulfur, sterilization was achieved by membrane filtration. Upon cooling, the medium was inoculated with 10 cc of the pure strain of Thiobacillus thiooxidans. The culture s initial pH value was read, and an initial gravimetric sulfate assay was performed. Thereafter, pH and sulfate values were determined at two-day intervals for 25 days. 

Figure 1. Conversion of organic sulfide into sulfate in 25-day period...

The pyridine-catalysed Cr(V) oxidation of organic sulfides to sulfoxides may be explained by Michaelis-Menten (MM) kinetics between intermediate Cr(V)-catalyst and Cr(V)-catalyst-substrate complexes.14... 

Bloodworth AJ, Courtneidge JL, Davies AG (1984) Rate constants for the formation of oxiranes by y-scission in secondary p-t-butylperoxyalkyl radicals. J Chem Soc Perkin Trans 2 523-527 Bohr V (2002) Repair of oxidative DNA damage in nuclear and mitochondrial DNA, and some changes with aging in mammalian cell. Free Rad Biol Med 32 804-812 Bonifacic M, Stefanic I (2000) Oxidation of organic sulfides by peroxyl radicals search for an adduct intermediate. Nukleonika 45 39-44... 

Schmidt KH, Flan P, Bartels DM (1995) Radiolytic yields of the hydrated electron from transient conductivity improved calculation of the hydrated electron diffusion coefficient and analysis of some diffusion-limited (e )aq reaction rates. J Phys Chem 99 10530-10539 Schoneich C, Aced A, Asmus K-D (1991) Halogenated peroxyl radicals as two-electron-transfer agents. Oxidation of organic sulfides to sulfoxides. J Am Chem Soc 113 375-376 Schuchmann Fl-P, von Sonntag C (1981) Photolysis at 185 nm of dimethyl ether in aqueous solution Involvement of the hydroxymethyl radical. J Photochem 16 289-295 Schuchmann Fl-P, von Sonntag C (1984) Methylperoxyl radicals a study ofthey-radiolysis of methane in oxygenated aqueous solutions. Z Naturforsch 39b 217-221 Schuchmann Fl-P, von Sonntag C (1997) Heteroatom peroxyl radicals. In Alfassi ZB (ed) Peroxyl radicals. Wiley, Chichester, pp 439-455... 

Studies of the oxidation of organic sulfides with amino acid-derived ligands in acetonitrile revealed very little difference between the mechanism of their oxidation and that of halides, except for one major exception. Despite the fact that acid conditions are still required for the catalytic cycle, hydroxide or an equivalent is not produced in the catalytic cycle, so no proton is consumed [48], As a consequence, there is no requirement for maintenance of acid levels during a catalyzed reaction. Peroxo complexes of vanadium are well known to be potent insulin-mimetic compounds [49,50], Their efficacy arises, at least in part, from an oxidative mechanism that enhances insulin receptor activity, and possibly the activity of other protein tyrosine kinases activity [51]. With peroxovanadates, this is an irreversible function. Apparently, there is no direct effect on the function of the kinase, but rather there is inhibition of protein tyrosine phosphatase activity. The phosphatase regulates kinase activity by dephosphorylating the kinase. Oxidation of an active site thiol in the phosphatase prevents this down-regulation of kinase activity. Presumably, this sulfide oxidation proceeds by the process outlined above. 

Smith, T.S. and V.L. Pecoraro. 2002. Oxidation of organic sulfides by vanadium haloperoxidase model complexes. Inorg. Chem. 41 6754—6760. 

The effect of the particular functional group on adsorption, however, is not always the same as seen on oxide surfaces. For example, carboxylic acids adsorb strongly on metal oxide surfaces, and the heat of adsorption of stearic acid is higher than that of the corresponding ester, methyl stearate (Hironaka et al., 1978). For adsorption on the nascent surface, however, propionic acid is a poor adsorbate, and the adsorption activity of propionic acid is lower than that of methyl propionate. Although propyl amine adsorbs easily on metal oxide surfaces, the adsorption activity of propyl amine is low on the fresh steel surfaces. Also, the heat of adsorption of organic sulfides on iron oxide is less than that of esters (Forbes et al., 1970b), but the results of adsorption activity on the nascent surface were the opposite. It is thus noteworthy that the chemical nature of the nascent surface of steel is often opposite to that of oxide-covered metal surfaces, with respect to adsorption. 

Figure 8 Examples of oxygen transfer to different substrates using hydroperoxo or alkylperoxo species A, the epoxidation of olefins catalyzed by Mo (VI) complexes as in the Oxirane process B, the Baeyer-Villiger oxidation of ketones catalyzed by Pt(II) complexes C, the epoxidation of olefins catalyzed by Ti(IV) silicates D, the oxidation of organic sulfides catalyzed by V(V) complexes.

As enantiomericaUy pure sulfoxides are excellent chiral auxUiaries for asymmetric synthesis, different approaches for biocatalytic asymmetric oxidations at the S-atom have been explored [30, 31]. Asymmetric peroxidaseorganic sulfides to sulfoxides in organic solvents opens up attractive opportunities by increased substrate solubility and diminished side reactions [32]. Plant peroxidases located in the cell wall are capable of oxidizing a broad range of structurally different substrates to products with antioxidant, antibacterial, antifungal, antiviral, and antitumor activities [33]. Hydroperoxides and their alcohols have been obtained in excellent e.e. in the biocatalytic kinetic resolution of secondary hydroperoxides with horseradish and Coprinus peroxidase [34]. 

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