Alkyl sulfides, preparation

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

Benzothiazolyl alkyl sulfides, prepared from the corresponding alcohols, are easily desulfurized (87-99%) by TBTH-AIBN. This reaction constitutes a good indirect deoxygenation of alcohols. Desulfurization of dithioketals may be controlled. Thus 1,3-dithiolanes with 1 mol equiv. of TBTH lead to 3-alkyl (or 3-aryl) thiols (64-82%), while 4 mol equiv. of TBTH leads to the completely desulfurized derivative. Desulfurization of heterocyclic thiones is also performed with this reagent. In passing, it should be noted that generation of radicals from C—S bonds and tin hydrides in the presence of radical initiators is of large synthetic interest. ... 

Alkyl phosphates, preparation, 16, 9 Alkyl sulfates, preparation, 19, 27 Alkyl sulfides, preparation, 15, 72 Alkyl sulfites, preparation, 19, 29 Ai-AlkyW -toluidines, 18,42 Allanioin, 13,1 Allyl alcohol, 10, 107 16, 85 Allylamine, 18, 5 Allyl cyanide, 16, 85 Allyl isothiocyanate, 18, 5 Alumina, 17, 27... 

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],... 

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. 

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. ... 

The preparations of aryl sulfides typically employ aryl halides as starting materials. The procedure described here makes use of the ubiquitous class of commercially available phenolic compounds in the form of aryl triflates, which expands the range of readily accessible aryl sulfides. Prior to this disclosure, the use of aryl triflates in a palladium-catalyzed process for the formation of aryl alkyl sulfides was unprecedented. This procedure appears to be general with regard to electronically neutral or electron-deficient aryl triflates (Table 1). The yields in Table I correspond to the initially disclosed procedure employing sodium (ert-butoxide as the base. Lower yields were obtained with the 4-nitro-... 

VO(OR)3 are very convenient and easily available precursors for the preparation of a wide range of V(V) derivatives and via their reduction by matalla-lkyls even for the derivatives of the lower oxidation states. The complete or partial substitution of OR-groups has led to halides, carboxylales, P-diketo-nates, alkyls, sulfides, azids, complexes with Shiffbases, phenylisocyanate, and so on. Hydrolysis of VO(OR)3 is discussed in Chapter 9. 

Irradiation with a mercury lamp of (diacyloxyiodo)benzene (64) in the presence of disulfide, generates the corresponding alkyl sulfide (65) together with iodobenzene and carbon dioxide (eq. 2.31) [75, 76]. This is useful for the preparation of adamantyl sulfides or selenides, since the preparation of such caged tert-alkyl sulfides or selenide is not so easy with polar reaction methods. 

Ham and coworkers85 have developed a one-pot synthetic method for the formation of aryl-alkyl sulfides, 94, from various alkyl halides and lithium aryl thiolates 93, which are prepared in situ from 92 formed by lithium—halogen exchange of 91, employing n-butyllithium (Scheme 31). The method avoids the use of unstable arylthiols and a catalyst is not required. Several aryl bromides were successfully employed in the reaction, and the corresponding sulfides were obtained in 71 to 96% yields. 

Very simple and straightforward alkylation of NH-heterocycles (NaH, Cl(CH2) SMe, = 2 or 3, 68-86%) permits one-pot preparation of pyrrole and carbazole sulfide models for the reaction with triflic anhydride <2003S1191>. Cyclization of the (l/7-pyrrol-l-yl)alkyl sulfides 1470 obtained leads to 2,3-dihydropyrrolo[2,l- ][l,3]thiazole 1472 and 3,4-dihydro-2/7-pyrrolo[2,T ][l,3]thiazine 1473 via intermediate l-methyl-2,3-dihydropyrrolo[2,l-/ ][l,3]thiazol-1-ium or l-methyl-3,4-dihydro-27/-pyrrolo[2,T ][l,3]thiazin-Tium salts 1471 (n = Z or 3), respectively, that were isolated in high yields in most cases (Scheme 281) <2003S1191>. 

Diacyl sulfides, preparation, 558 Dialdehydes, preparation, 286, 291 preparations listed in table 26, 303 Diamides, dehydration, 597 Hofmann degradation, 675 preparations listed in table 63, 580 Diamines, alkylation, 668... 

The t-butyl sulfide reagent provides access to tetramers difficult to prepare by other methods. The order of reactivity in this replacement correlates with the acidity of the RSH reagent aryl sulfides replace alkyl sulfides, which have reactivity order p-XC6H4SH, X = NO2, Me, H, NMc2, [NMc3] PhCHjSH HOCH2CH2SH EtSH. The synthetic analogues of iron-sulfur proteins are described. ... 

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