Disulfides applications, sulfides

Adewuyi, Y.G. and Carmichael, G.R. Kinetics of hydrolysis and oxidation of carbon disulfide by hydrogen peroxide in alkaline medium and application to carbonyl sulfide, Environ. Sci. Technol, 21(2) 170-177, 1987. 

The elemental fuels applicable to IE production are not as obvious as the hydrocarbons described above and simply have to be learned and memorized. Those most prevalent are powdered metals (aluminum, magnesium, titanium), carbon disulfide, phosphorus, sulfur, and antimony sulfide. One important side note is that, for the most part, these elemental fuels produce IE formulations that are very sensitive and often unstable. Mixtures incorporating any of them should be treated with extra caution. 

Other components in the feed gas may react with and degrade the amine solution. Many of these latter reactions can be reversed by application of heat, as in a reclaimer. Some reaction products cannot be reclaimed, however. Thus to keep the concentration of these materials at an acceptable level, the solution must be purged and fresh amine added periodically. The principal sources of degradation products are the reactions with carbon dioxide, carbonyl sulfide, and carbon disulfide. In refineries, sour gas streams from vacuum distillation or from fluidized catalytic cracking (FCC) units can contain oxygen or sulfur dioxide which form heat-stable salts with the amine solution (see Fluidization Petroleum). 

In situ generated acyllithium reagents not only can acylate ketones, but also can acylate aldehydes,3 esters,4 lactones,5 isocyanates and isothiocyanates,6 carbodiimides,7 carbon disulfide and carbonyl sulfide,8 organic disulfides,9 and trialkylchlorosilanes.10 For reviews, see references 11 and 12. This direct, nucleophilic acylation procedure, when applicable, makes unnecessary the usually... 

Many individual flavor chemicals which were isolated and identified from Maillard "side reactions" have been reported in the patent literature. It is evident from these patents that much work has been done to glean specific flavor chemicals from the complexities of the Maillard reaction. 3-Furyl alkyl sulfide, disulfide, and 0-chalcogenalkyl sulfide derivatives are claimed to provide bloody, meaty, and roasted notes to beef broth and beef products (64-66). 3-Methylcyclopent-2-en-l-one was declared for its flavor eiiEancement of beef bouillon (67). Firmenich claimed 2,6-dimethyl-2-octenal and its analogs as possessing meat flavor qualities (68). A method to produce disulfides for application to meat and savory flavors was patented (69). 

The principal use of titanium sulfides is as a cathode material in high efficiency batteries (11). In these applications, the titanium disulfide acts as a host material for various alkali or alkaline-earth elements. 

These methods suggested in the present form by Caunt83) rely on inhibition (retardation) effects of strong catalyst poisons on polymerization. Typical poisons potentially usable for this purpose are carbon oxides, carbonyl sulfide, carbon disulfide, acetylenes and dienes. All these substances exhibit a strong unsaturation they have either two double bonds or one triple bond. Most of the works devoted to application of the poisons to determination of active centers 10,63 83 102 1O7) confirm a complicated nature of their interaction with the catalytic systems. To determine the active centers correctly, it is necessary to recognize and — as much as practicable — suppress side processes, such as physical adsorption and chemisorption on non-propagative species, interaction with a cocatalyst, oligomerization and homopolymerization of the poison and its copolymerization with the main chain monomer. 

This reaction has found little application to mercaptan syntheses since the mercaptans are usually as readily available (by other methods) as the disulfides. The S-S linkage is reduced by zinc in acetic or sulfuric " acid, lithium aluminum hydride, or metallic sodium. y-Hydroxy-propyl disulfide is reduced electrolytically in 70% yield. Reduction by sodium disulfide does not reduce the nitro group in the preparation of p-nitrothiophenol (65%), whereas zinc and acetic acid converts o-nitro-phenyl disulfide to o-aminothiophenol (90%). Disulfides made by the action of ammonium hydrogen sulfide on aldehydes are sources for difficultly available aromatic and heterocyclic mercaptans. The disulfides are reduced by aluminum amalgam and water. ... 

The rapid development of chiral phosphine derivatives of ferrocene was undoubtedly due to their application in catalysis. In contrast, chiral sulfur compounds from lithiated iV,iV-dimethyl-l-ferrocenylethylamine were only prepared about 15 years later [140], For the synthesis of such derivatives, the lithiated amine is treated with disulfides as shown in Fig. 4-24, top (and analogously, diselenides [141]). The sulfides obtained are easily oxidized by peracids or NaI04 to the corresponding sulfoxides. As sulfur becomes a new center of chirality by the oxidation, diastereoisomeric sulfoxides are formed in ratios depending on the oxidant [140]. If chiral oxaziridines [106, 142] are used as oxidizing agents, the diastereoisomeric ratio is appreciably... 

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