Sulfides alkyl

Various S-nucleophiles are allylated. Allylic acetates or carbonates react with thiols or trimethylsilyl sulfide (353) to give the allylic sulfide 354[222], Allyl sulfides are prepared by Pd-catalyzed allylic rearrangement of the dithio-carbonate 355 with elimination of COS under mild conditions. The benzyl alkyl sulfide 357 can be prepared from the dithiocarbonate 356 at 65 C[223,224], The allyl aryl sufide 359 is prepared by the reaction of an allylic carbonate with the aromatic thiol 358 by use of dppb under neutral condi-tions[225]. The O-allyl phosphoro- or phosphonothionate 360 undergoes the thiono thiolo allylic rearrangement (from 0-allyl to S -allyl rearrangement) to afford 361 and 362 at 130 C[226],... 

Nucleophilic reactivity of exocyclic sulfur appears in acidic medium. 2-AryI thiazolyl sulfones are obtained from the corresponding sulfides by oxidation with HjO- in HOAc at 100°C (272). The same oxidation takes place with alkyl sulfides (203. 214, 273-275) and dithiazolylsulfides (129). However, the same reaction with 2-benzylthio derivatives gives benzylal-cohol and the related A-4-thiazoline-2-thione (169). 

For example, p-bromophenacylaryl (or alkyl) sulfides (160) with 157, R] =Et, yield the 5-(aryl or alkyl)-thiothiazolyl-2-ones (161) (Scheme 82) (487). 

The 3 -heterocychcs ia the mid-distiUate range are primarily the thiacyclanes, ben2othiophenes, and diben2othiophenes. There are lesser amounts of dialkyl—, diaryl—, and aryl—alkyl sulfides (29). Alkylthiophenes are scarce or absent, but some evidence exists for ben2thiacyclanes (Fig. 6). As for the naphtha fractions, these sulfur species account for a minimal fraction of the total sulfur ia the cmde. 

Organosulfur Adsorbates on Metal and Semiconductor Surfaces. Sulfur compounds (qv) and selenium compounds (qv) have a strong affinity for transition metal surfaces (206—211). The number of reported surface-active organosulfur compounds that form monolayers on gold includes di- -alkyl sulfide (212,213), di- -alkyl disulfides (108), thiophenols (214,215), mercaptopyridines (216), mercaptoanilines (217), thiophenes (217), cysteines (218,219), xanthates (220), thiocarbaminates (220), thiocarbamates (221), thioureas (222), mercaptoimidazoles (223—225), and alkaneselenoles (226) (Fig. 11). However, the most studied, and probably most understood, SAM is that of alkanethiolates on Au(lll) surfaces. 

Formation of Sulfides. Thiols react readily with alkenes under the same types of conditions used to manufacture thiols. In this way, dialkyl sulfides and mixed alkyl sulfides can be produced. Sulfides are a principal by-product of thiol production. Mixed sulfides can be formed by the reaction of the thiol using a suitable starting material, as shown in equations 21, 22, and 23. Vinyl sulfides can be produced by the reaction of alkynes with thiols (38). 

Various alkylating agents are used for the preparation of pyridazinyl alkyl sulfides. Methyl and ethyl iodides, dimethyl and diethyl sulfate, a-halo acids and esters, /3-halo acids and their derivatives, a-halo ketones, benzyl halides and substituted benzyl halides and other alkyl and heteroarylmethyl halides are most commonly used for this purpose. Another method is the addition of pyridazinethiones and pyridazinethiols to unsaturated compounds, such as 2,3(4//)-dihydropyran or 2,3(4//)-dihydrothiopyran, and to compounds with activated double bonds, such as acrylonitrile, acrylates and quinones. 

Paint and varnish manufacturing Resin manufacturing closed reaction vessel Varnish cooldng-open or closed vessels Solvent thinning Acrolein, other aldehydes and fatty acids (odors), phthalic anhydride (sublimed) Ketones, fatty acids, formic acids, acetic acid, glycerine, acrolein, other aldehydes, phenols and terpenes from tall oils, hydrogen sulfide, alkyl sulfide, butyl mercaptan, and thiofen (odors) Olefins, branched-chain aromatics and ketones (odors), solvents Exhaust systems with scrubbers and fume burners Exhaust system with scrubbers and fume burners close-fitting hoods required for open kettles Exhaust system with fume burners... 

Thiophenethiols are prepared by reduction of the sulfonyl chlorides or, more conveniently, by the reaction of Grignard rea-gents or thienyllithium compounds with sulfur. They have also been obtained by cleavage or thienyl alkyl sulfides with sodium in liquid ammonia. 3-Thiophenethiol is a by-product in the commercial thiophene synthesis. Thiophenethiols have recently also been prepared by a synthesis involving Friedel-Crafts reaction of 2,4-dinitrobenzenesulfenyl chloride with thiophenes, followed by basic cleavage of the resulting sulfide. ... 

Alkyl phosphates, preparation, 16, 9 Alkyl sulfides, preparation, 15, 72 JV-Alkyl- -toluidines, 18, 42 Allantoin, 13,1... 

Subsequently, a number of reactions at poly-L-valine coated carbon electrodes 237-243) gj.g reported to yield optically active products. Reductions, e.g. of citraconic acid or l,l-dibromo-2,2-diphenylcyclopropane as well as the oxidation of aryl-alkyl sulfides proceeded with chiral induction at such electrodes... 

In 2008, Rykowski et al. reported the synthesis of optically active 2,2 -bipyridine alkyl sulfoxides by asymmetric oxidation of their corresponding readily accessible 2,2 -bipyridine alkyl sulfides. These sulfoxides were further evaluated as ligands for the enantioselective addition of ZnEt2 to benzaldehyde, providing only low enantioselectivities of up to 14% ee (Scheme 3.34). 

Micellaneous Vitamins, plant growth regulators (auxin.s, cytokinins, gib-berellins), alkyl sulfides, ethanol, H. K nitrate, phosphate, HCO,... 

For some organic compounds, such as phenols, aromatic amines, electron-rich olefins and dienes, alkyl sulfides, and eneamines, chemical oxidation is an important degradation process under environmental conditions. Most of these reactions depend on reactions with free-radicals already in solution and are usually modeled by pseudo-first-order kinetics ... 

A class of enzymes capable of removing sulfur from alkane sulfonates exists, which may have relevance in microbial desulfurization of alkyl sulfides. A gene cluster ssuEADCB was identified in E. coli. The enzyme SsuD was capable of conversion of pentane sulfonic acid to pentaldehyde and sulfite. It was reported to be capable of conversion of alkyl sulfonates from C2 to CIO, as well as substituted ethanesulfonates and sulfonated buffers. The SsuE was a flavin-reducing enzyme that provided FMNH2 to the SsuD. 

In 1978 and 1980 the coupling of aryl bromides and iodides with both aliphatic and aromatic thiols was first reported in the presence of NaO-t-Bu and Pd(PPh3)4 (Equation (35)).118,119 In contrast to aryl halide aminations and etherifications, the thiation reactions did not require unusual catalysts. Yet, reactions that form aryl alkyl sulfides from alkyl thiols occurred in modest yields in many cases ... 

Structure, acidity and basicity 100 Oxidation of sulfinic acids 101 Disproportionation 102 Reactions with alkyl sulfides and disulfides 103 Desulfonylation 106... 

Kice et al., 1967). The kinetics of the acid- and sulfide-catalyzed reaction of thiolsulfinates with sulfinic acids show that its mechanism involves a rate-determining nucleophilic attack of the alkyl sulfide on the protonated... 

In relatively acid solutions, aromatic sulfinic acids and alkyl sulfides undergo an interesting reaction having the stoichiometry shown in (110) (Kice and... 

The hydrolysis of aryl sulfinyl sulfones can be catalyzed by alkyl sulfides such as n-butyl sulfide (Kice and Guaraldi, 1967, 1966b). The dependence of rate on sulfide structure (for variation of R in R2S, p = —1.6) indicates that the sulfide acts as a nucleophile (Kice and Guaraldi, 1966b). This sulfide-catalyzed hydrolysis also, however, requires acid catalysis, i.e. Rate = its[H+][R2S] [ArS(0)S02Ar]. Presumably the need for acid catalysis arises as follows. In intermediate [38], akin to the situation discussed above for [37], loss of ArS02... 

Alkyl sulfides are not the only nucleophiles that can catalyze the hydrolysis of sulfinyl sulfones. The various halide ions, thiocyanate ion, acetate ion, and thiourea, are very effective catalysts (Kice and Guaraldi, 1968). The mechanism for the hydrolysis as catalyzed by these nucleophiles is shown in... 

Similarly, the metal-catalyzed oxidation of aryl alkyl sulfides by t-butyl hydroperoxide carried out in a chiral alcohol gives rise to optically active sulfoxides of low optical purity (e.e., 0.6-9.8%) (57). 

Saturated heteroatomic systems Alkyl sulfides Cycloalkyl sulfides Alkyl side chains on ring systems... 

The total sulfur content (ASTM D1072, D2784, D3031) is normally acceptably low, frequently so low that it needs augmentation by means of alkyl sulfides, mercaptans, or thiophenes in order to maintain an acceptable safe level of odor. 

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