Dibenzyl sulfide oxidation

Despite the fact that dibenzothiophene can be readily oxidized with peracetic acid, it is generally resistant to milder oxidative conditions. It is, for example, stable to heating in an inert solvent at 150° in the presence of bronze and oxygen, conditions under which both biphenyl sulfide and dibenzyl sulfide gave insoluble precipitates. It is not surprising, therefore, that dibenzothiophene has been reported to have little or no antioxidant properties and more recent work has generally confirmed this. Octahydrodibenzothiophene has, however, been reported to be useful as an oil antioxidant. ... 

Similar behavior of other aromatic disulfides and thiols on gold electrodes has been described based on the SERS experiments [167]. Adsorption of benzenethiol, benzenemethanethiol, p-cyanobenzenemethanethiol, diphenyl sulfide, and dibenzyl sulfide was studied on the roughened gold electrode. All these species adsorb dissociatively as the corresponding thiolates. Monolayers formed from symmetric disulfides were exactly like those formed from the corresponding thiols. These monolayers were stable in a wide potential window from -1-800 to —1000 mV (versus SCE), which was limited by the oxidation of the Au surface from the positive side and hydrogen evolution at —1000 to —1200 mV at the negative side. 

X-ray Photoelectron Spectroscopy (XPS) tests were conducted on surfaces lubricated with a sulfur-containing extreme pressure additive, dibenzyl sulfide (Baldwin, 1976 Bird and Galvin, 1976). The films can arise from the use of additives that contain sulfur, phosphorus, chlorine, bromine, or boron and the differences in reactivity are affected by the formation of protective layers. Triboinduced electrons are said to activate the formation of iron halides, iron phosphates and iron sulfides (Dorison and Ludema, 1985 Grunberg, 1966 Kajdas, 2001 McFadden et al., 1998 ). When a chemical reaction takes place, e.g., oxygen interacts with aluminum to form aluminum oxide, a large oxygen peak is seen at approximately 500 eV in the Auger electron spectra (Benndorf et al., 1977 Nakayama et al., 1995). 

Alkyl sulfides. Di-n-butyl sulfide and dibenzyl sulfide have been oxidized to the sulfoxides by prolonged shaking of a petroleum ether solution with active MnOj. Diallyl sulfoxide was obtained by this method in 13% yield. 

Thiophenol is oxidized with DCT or TBT to diphenyl disulfide. The latter reacts with DCT under more rigid conditions to give benzyl chloride. DCT oxidizes dibenzyl sulfide in methanol to dibenzyl sulfoxide (69ZC325) (Scheme 120). 

Bacteria selected for growth with bis-(3-pentflnorophenylpropy)-sulfide as sulfur source are able to use dimethyl sulfoxide, dibenzyl snlfide, and some long-chain disulfides as sources of sulfur (van Hamme et al. 2004). Degradation takes place by oxidation to the sulfone, scission of the C-S bond to an alkanol, and an alkyl sulfinate that is degraded with loss of the snlfnr, which is nsed for growth. 

Dibenzyl trisulfide provides a useful source of sulfur for the preparation of sulfide anions via oxidative replacement of R8 ligands (equation 38). [Fe2(/r-82)(85)2] contains two Fe85 rings bridged by two 8 anions. 

Contrary to DCT, reaction of CBT with diphenyl sulfide is not smooth. Benzyl chloride, dibenzyl disulfide, and some unidentified products were obtained. In the case of di-tert-butyl sulfide the formation of oxidation products was not observed [69JCS(CC)365]. 

Organic sulfides are oxidized to sulfonyl chlorides by iodosylbenzene, activated by crushing and grinding with a HCl-treated silica gel [522,523], Sulfides 431 with benzylic substituents, such as dibenzyl, alkyl benzyl and benzyl phenyl sulfides, are converted by this reaction into the corresponding sulfonyl chlorides 432 and 433 in high yields (Scheme 3.173). Other types of sulfides, such as dialkyl and alkyl phenyl sulfides, give sulfonyl chlorides only in moderate yield. 

Formamidinesulfmic acid (obtained by the oxidation of thiourea with hydrogen peroxide) has been used to reduce disulfides to sulfides (see Eqs. 12.6 and 13.22) and N-tosylsulfilimines to sulfides (see Eqs. 12.7 and 13.23), under phase transfer catalytic conditions in the presence of hexadecyltributylphosphonium bromide [15]. Diphenyl, dibenzyl and dibutyldisulfides were reduced by this method to the corresponding sulfides in 72%, 62% and 90% yields respectively. Examples of the reduction of N-tosylsulfilimines are recorded in Table 12.4. 

More recently it was found that methyl sulfide-iV-chlorosuccin-imide in toluene at 0°C gives good yields of ketones by the oxidation of primary and secondary alcohols. However, allylic and dibenzylic alcohols give halides. The latter alcohols can be oxidized to ketones with a dimethyl sulfoxide-chlorine reagent. 

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