Acyl iodides in organic synthesis. reaction of acetyl iodide with Dialkyl sulfides and disulfides

Reactions of acetyl iodide with dialkyl and dialkenyl sulfides RSR (R = Et, Bu, CH₂=CH, CH₂=CHCH₂) and with disulfides RSSR (R = Pr, C₆H₁₃, PhCH₂) were studied. Dialkyl sulfides reacted with MeCOI to give the corresponding alkyl ethanethioates and alkyl iodides as a result of cleavage of the S-C bond. The reactions of acetyl iodide with divinyl and diallyl sulfides involved addition across the double bond and subsequent polymerization of 1-alkenylsulfanyl-2(3)-iodoalkyl methyl ketones. Dialkyl disulfides RSSR (R = Pr, C₆H₁₃) and dibenzyl disulfide reacted with acetyl iodide via cleavage of the S-S bond to produce the corresponding ethanethioates and organylsulfenyl iodides. The latter underwent disproportionation to form the initial disulfide and molecular iodine.     

Selective synthesis of organic sulfides and disulfides by the reduction of elemental sulfur with samarium diiodide

Elemental sulfur can be reduced to the corresponding thiolate anion species (S²⁻ and S²⁻₂) selectively by samarium diiodide in the presence and absence of HMPA, respectively. The subsequent alkylation of the thiolate anion species provides a useful synthetic route to dialkyl sulfides and disulfides. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9: 581–584, 1998     

Oxidation of organic sulfides by vanadium haloperoxidase model complexes

In addition to halide oxidation, the vanadium haloperoxidases are capable of oxidizing sulfides to sulfoxides. Four vanadium complexes with tripodal amine ligands, K[VO(O(2))(heida)] (1), VO(2)(bpg) (2), K[VO(2)(ada)] (3), and K(2)[VO(O(2))(nta)] (4), previously shown to perform bromide oxidation (Colpas, G. J.; Hamstra, B. J.; Kampf, J. W.; Pecoraro, V. L. J. Am. Chem. Soc. 1996, 118, 3469-3477), have now been shown to oxidize aryl alkyl sulfides to the corresponding sulfoxides. The oxidation was observed by the disappearance of thioanisole's ultraviolet absorption at 290 nm, by the change in the aromatic region of the (1)H NMR spectrum of the sulfides, and by changes in the complexes' (51)V NMR spectra. The amount of methyl phenyl sulfide oxidized in 3 h was 1000 equiv (per metal complex). The oxidation product is almost exclusively sulfoxide, with very little sulfone (less than 3% over a 3 h experiment) formed. This is consistent with an electrophilic oxidation mechanism, as had been proposed for oxidation of bromide by 1-4. The rate was found to be first order in substrate concentration, similar to the rate law observed for bromide oxidation. Unlike the bromide oxidation, the equivalent of acid required for peroxovanadium complex activation is not consumed. The complexes 1-4 are not reactive with styrene or cyclooctene. The relevance of these reactions to the mechanism of the vanadium haloperoxidases and, more generally, peroxovanadium oxygenation of sulfides will be discussed.     

Interaction of acetylene with organic disulfides

Conclusions Dialkyl disulfides are added to acetylene, forming 1,2-bis(alkyithio)ethenes and vinylalkyl sulfides.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 454–456, February, 1967.     

Synthesis of aryl perfluoroalkyl sulfides from aromatic disulfides

Thermolysis of xenon(ii) bis(perfluoroalkanecarboxylates) in the presence of diaryl disulfides occurs through the S—S bond cleavage to form dihalo-, halonitro-, and halodinitrophenyl perfluoroalkyl sulfides. The latter type of compounds was obtained for the first time. The main side process is the perfluoroalkylation of the aromatic ring.     

Catalytic synthesis of dialkyl sulfides from dialkyl disulfides

Dialkyl disulfides R₂S₂ where R = Me, Et, or Pr, both as individual compounds and as their mixtures, isolated from petroleum products can turn into alkanethiols and dialkyl sulfides under the action of catalysts having strong acid sites and medium-strength basic sites on their surface. In a helium atmosphere, the main conversion products are alkanethiols, while dialkyl sulfides form in low yield at a selectivity of no higher than 20%. A much higher dialkyl sulfide selectivity is attained in the reaction involving methanol. The most efficient catalyst for this reaction is alumina, with which the dialkyl sulfide selectivity is up to 99%.     

Fluorination of perfluoroalkylsulfenyl chlorides,perfluorodialkyl disulfides and perfluorodialkyl sulfides with chlorine monofluoride

In reactions with perfluoroalkylsulfenyl chlorides (R_fSCl; R_f = F₃, C₂F₅, n-C₃F₇, n-C₄F₉) and perfluoroalkyl disulfides (R_fSSR_f′; R_f = R_f′ = CF₃, R_f = CF₃, R_f′ = C₂F₅) at 25°, chlorine monofluoride acts primarily as a chlorinating and fluorinating reagent to give the corresponding perfluoroalkylsulfur chloride tetrafluorides, R_fSF₄Cl, in good yields. However, small amounts of perfluoroalkylsulfur pentafluorides, R_fSF₅, are also obtained. A mixture of the cis and trans isomers of bis(trifluoromethyl)sulfur tetrafluoride and of trifluoromethyl pentafluoroethylsulfur tetrafluoride has been formed by the reaction of the corresponding bis(perfluoroalkyl) sulfides and chlorine monofluoride. The new perfluoroalkylsulfur chloride tetrafluorides are colorless, unpleasant smelling liquids. The infrared, mass and ¹⁹F NMR spectral data, as well as thermodynamic and elementary analysis data, are given for the new compounds.     

Oxidation of polyfunctional sulfides with chlorine dioxide

3-Benzylsulfanyl-4,5-diphenyl-4H-1,2,4-triazole, 5-methylsulfanyl-1-phenyl-1H-tetrazole, 2-methylsulfanyl-1H-benzimidazole, 2-benzylsulfanyl-1H-benzimidazole, and 1-butylsulfanyl-4-nitrobenzene were oxidized to the corresponding sulfoxides with chlorine dioxide using different modes of oxidant supply. The oxidation process was characterized by high chemoselectivity.     

Oxidation of organic sulfides with atmospheric oxygen in the presence of phthalocyanine complexes as catalysts

Catalytic oxidation of a mixture of low-molecular-weight sulfides with atmospheric oxygen was studied. The catalytic activity of poly(cobalt phthalocyanine) in this process is higher than that of monomeric cobalt phthalocyanine.     

Oxidation of prochiral sulfides with chiral dioxirane

Dioxirane generated in situ by reaction of chiral 1,2:4,5-di-O-isopropylidene-D-erythro-hexo-2,4-diulo-2,6-pyranose with Oxone oxidizes prochiral sulfides to the corresponding sulfoxides with an enantiomeric excess of 2 to 25%.     

Oxidation of organic sulfides and sulfoxides by oxygen in the presence of copper complexes

In liquid-phase oxidation of sulfides and sulfoxides by air oxygen in acetone solution a high catalytic activity is shown by copper(II) phenolates containing electrodonor substituents in their benzene ring. Reactivity of aliphatic sulfides with R=C₁–C₅ in sulfoxide formation is 5–10 times higher than that of petroleum sulfides. Oxidation rate of sulfides to sulfoxides is by an order of magnitude higher than that of sulfoxides to sulfones.

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(II), - . R=C₁–C₅ 5–10 , . .

     

Oxidation of γ-oxo sulfides with chlorine dioxide

γ-Oxo sulfides were oxidized to the corresponding sulfoxides with an aqueous solution of chlorine dioxide.     

Acidity of organic sulfides

The rate of base-catalyzed hydrogen exchange (bases KNH₂ in NH₃. t-C₄H₃OK in t-C₄H₃OH) has been used to mesure the acidity of sulfides RSCD₃, in which R is CH₃, C₆H₆, C₆H₁₁, or C₅H₈, The cycloalkyli are found to act as electron acceptors. The effects of one and two CH₈ and SC₆H₆ are examined. The sulfides are compered with hydrocarbons and also with 3CH₃, OCH₁ and NCH₃ attached to benzene. The vacant 3d levels of the sulfur stabilize the sulfide carbanions; deuterium exchange shows that the charge distribution ir.p-dimethylaminothiazole is due to pd conjugations. Synthesis routes are described for compounds tagged with deuterium in specified positions: C₆H₁₁SCD₃, C₆H₈SCD₁, C₆H₅SCD₁CH₃, C₆H₃SCD(CH₃)₂, p-(CH₃)₂NC₅H₄SCD₃, and p-(CD₃)₂NC₅H₄SCH₃.     

Catalytic enantioselective oxidation of sulfides and disulfides by a chiral complex of bis-hydroxamic acid and molybdenum

A chiral bis-hydroxamic acid (BHA)-molybdenum complex was used for the catalytic asymmetric oxidation of sulfides and disulfides utilizing one equivalent of alkyl peroxide with yields up to 83% and ee up to 86%. An extension of our methodology combines the asymmetric oxidation with kinetic resolution providing excellent enantioselectivity (ee 92–99%).     

Reactions of thiols and organic disulfides with iron and its oxides

The influence of O₂ and H₂O on the formation of iron dithiolates (IDTs) by the reactions of thiols and organic disulfides with the iron powder was studied under the static (without mechanical activation of the reaction) and dynamic (with mechanical activation of the reaction) conditions. Under the static conditions in the absence of O₂ or H₂O, only BnSH and PhSH give IDTs, whereas DdSH (Dd is dodecyl) produces IDTs in the presence of O₂ or H₂O. For the mechanical activation of the reactions of organic disulfides with the iron powder, the formation of IDTs is possible if the reaction mixture contains H₂O. On the interaction with iron oxides excess thiols are oxidized to organic disulfides and also afford IDTs. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1383–1386, August, 2006.     

Synthesis of acylphosphine sulfides by rhodium-catalyzed reaction of acid fluorides and diphosphine disulfides

A rhodium complex catalyzed the reaction of acid fluorides and tetraethyldiphosphine disulfide giving acylphosphine sulfides. Aromatic acid fluorides with electron donating p-groups reacted smoothly giving the products in high yields. Aliphatic acid fluorides with secondary and tertiary α-carbons were also converted to alkanoylphosphine sulfides, whereas the reaction of a substrate with an α-methylene carbon was accompanied by enol ester formation.