Methanesulfenyl chloride

Fluoride ion attacks the sulfur atom in 2,3-diphenylthiirene 1,1-dioxide to give ck-1,2-diphenylethylenesulfonyl fluoride (23%) and diphenylacetylene (35%). Bromide or iodide ion does not react (80JOC2604). Treatment of S-alkylthiirenium salts with chloride ion gives products of carbon attack, but the possibility of sulfur attack followed by addition of the sulfenyl chloride so produced to the alkyne has not been excluded (79MI50600). In fact the methanesulfenyl chloride formed from l-methyl-2,3-di- -butylthiirenium tetrafluoroborate has been trapped by reaction with 2-butyne. A sulfurane intermediate may be indicated by NMR experiments in liquid sulfur dioxide. 

The difference between the distillation and pot temperatures is closely related to the success of this preparation. If the specified weights of reactants and temperatures are employed a 3 temperature difference should be reached before the yellow intermediate fraction, probably containing methanesulfenyl chloride, chloromethanesulfenyl chloride, and acetic acid, has attained a volume of 10 ml. Toward the end of the distillation the pot temperature may begin to rise owing to the presence in the residue of methanesulfonyl chloride (b.p. 63°/20 mm.,... 

DMSO or other sulfoxides react with trimethylchlorosilanes (TCS) 14 or trimefhylsilyl bromide 16, via 789, to give the Sila-Pummerer product 1275. Rearrangement of 789 and further reaction with TCS 14 affords, with elimination of HMDSO 7 and via 1276 and 1277, methanesulfenyl chloride 1278, which is also accessible by chlorination of dimethyldisulfide, by treatment of DMSO with Me2SiCl2 48, with formation of silicon oil 56, or by reaction of DMSO with oxalyl chloride, whereupon CO and CO2 is evolved (cf also Section 8.2.2). On heating equimolar amounts of primary or secondary alcohols with DMSO and TCS 14 in benzene, formaldehyde acetals are formed in 76-96% yield [67]. Thus reaction of -butanol with DMSO and TCS 14 gives, via intermediate 1275 and the mixed acetal 1279, formaldehyde di-n-butyl acetal 1280 in 81% yield and methyl mercaptan (Scheme 8.26). Most importantly, use of DMSO-Dg furnishes acetals in which the 0,0 -methylene group is deuter-ated. Benzyl alcohol, however, affords, under these reaction conditions, 93% diben-zyl ether 1817 and no acetal [67]. 

Because the reactive intermediate 1277 and methanesulfenyl chloride 1278 are electrophiles, they can react with olefins [72-75]. Thus d -steroids give rise to 6-)9-methylmercapto-zl" -steroids [74]. trans-6-Phenylcyclohex-3-ene-3-carboxyUc add 1291 reacts with DMSO/MesSiBr 16 to form, via 1292, the lactone 1293 in 87% yield, whereas attempted bromolactonization of 1291 affords only 59% 1294 [75] (Scheme 8.29). 

As a continuation to the studies by Darwish and Braverman on the [2,3]-sigmatropic rearrangement of allylic sulfinates to sulfones, and in view of its remarkable facility and stereospecificity (see Chapter 13), Braverman and Stabinsky investigated the predictable analogous rearrangement of allylic sulfenates to sulfoxides, namely the reverse rearrangement of that attempted by Cope and coworkers . These authors initiated their studies by the preparation of the claimed allyl trichloromethanesulfenate using the method of Sosnovsky . This method involves the reaction between trichloro-methanesulfenyl chloride and allyl alcohol in ether at 0 °C, in the presence of pyridine (equation 6). 

The preparation of 5-chloro-l,2,4-thiadiazol-2-ium chlorides 95 by treatment of formimidoyl isothiocyanates 94 with a twofold excess of methanesulfenyl chloride has been reported in an unusual variation of a type C synthesis. These salts show interesting chemical behavior toward several nitrogen and carbon nucleophiles. The nature of the N-substituent determines the stability of the salt 95. When the substitutent on nitrogen is /-butyl, the salt 95 decomposes readily in solution to give the 5-chloro-l,2,4-thiadiazole 96 (Scheme 10) <2003HAC95>. 

While the vast majority of the chemistry of thiolsulfonates involves reactions in which the sulfenyl sulfur acts as an electrophilic center and is attacked by nucleophiles, one example has been reported (Douglass, 1959) in which this same sulfur acts as a nucleophile. Methyl methanethiolsulfonate undergoes a very slow reaction with methanesulfenyl chloride that leads to the formation of methanesulfonyl chloride and dimethyl disulfide. The mechanism is believed... 

The more highly fluorinated isothiocyanates, F2CIC—NCS and FgC— NCS, even at 80°C with chlorine yield only the iminochloro-methanesulfenyl chlorides (2i) ... 

Thiolactones such as (41) undergo ring opening on treatment with the electrophilic sulfur compound methanesulfenyl chloride (72CHE432). 

Although very few studies of free-radical reactions of sulfenyl compounds have as yet been reported, irradiation with ultraviolet light enhances the rate of addition of CI3CSCI to olefins.218 Evidence for free-radical behavior is found in the easy decompositions which are observed for RSC1 under irradiation, e.g., the conversion of methanesulfenyl chloride to chloromethanesulfenyl chloride287 under the influence of sunlight. In the photoinitiated chlorination reaction with trichloro-... 

Introduction of thio substituents on to the pyrrole ring by electrophilic substitution has been demonstrated under several conditions for the parent molecule. Methanesulfenyl chloride gives 2-methylthiopyrrole (equation 212) (61JOC2615). Other electrophilic substitu-... 

The groups of Trost and coworkers and Caserio and coworkers independently developed procedures for azasulfenylation. Caserio reported that when alkenes are treated with a sulfenamide such as MeSN-Me2 in the presence of the Meerwein reagent trimethyloxonium tetrafluoroborate, azasulfenylation of the alkene is observed, presumably via the thioammonium ion MeSNMe3+ (equation 4).20 Boron trifluoride etherate can also serve as a catalyst for addition of sulfenamides to alkenes. The adduct stereochemistry is strictly anti as established by treatment of the dihydropyran methanesulfenyl chloride adduct (see Scheme 2) with AgBF4 followed by trimethylamine. 

Several types of sulfenyl chlorides are known. Sulfur monochloride and dichloride can add to dienes forming sulfor bridges. - The most commonly used sulfenyl halides are benzenesulfenyl dilorides and methanesulfenyl chloride. Other sulfenyl halides, such as acetylthiosulfenyl chloride and thiocyanogen chloride, have been added to alkenes, but few subsequent transformations have been carried out with those intermediates. 8... 

Treatment of alkene 72 with methanesulfenyl chloride afforded the adduct 74 via the intermediacy of a thiiranium ion 73 (Scheme 33). This intermediate 73 has been independently synthesized and was shown to react with A -methylpyridinium chloride to provide 74 <1992CC293>. 

The electrophilic reagents acetylsulfenyl chloride, methanesulfenyl chloride,sulfuryl chloride or chlorine, cleave the -thiolactone ring as shown for 332 and 307. Some disulfide may be formed along with the suite nyl derivative. 

Preparation. The reagent is prepared in 78% yield by oxidation of trichloro-methanesulfenyl chloride (Stauffer Chem. Co.) with hydrogen peroxide in acetic acid. ... 

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