Sulfides from sulfenyl chlorides

These sulfides are prepared from other sulfur protective groups by reaction with the sulfenyl chloride. The Npys group can also be introduced directly by treatment of the thiol with NpysCl. ... 

Elimination of hydrogen chloride from 2/f perfluoro-2-methylpropane-1 -sulfenyl chloride by the triethylamine-boron trifluoride complex results in cyclization to perfluoro-l,l-dimethylthiirane (perfluoroisobutylene sulfide) [, 9] (equation 9)... 

Pyridine iV-sulfides are known only in the form of their derivatives. Thus, 1-arylthiopyridinium cations (from pyridine and sulfenyl chloride) react with KCN to form ArSCN and pyridine (81CC703). Pyridine-sulfur trioxide is a mild sulfonating reagent, used for sulfonation of furan and pyrrole. 

Thiiranes can be formed directly and stereospecifically from 1,2-disubstituted alkenes by addition of trimethylsilylsulfenyl bromide, formed at -78 C from reaction of bromine with bis(trimethylsilyl) sulfide (Scheme 7).12 A two-step synthesis of thiiranes can be achieved by addition of succinimide-A/-sulfe-nyl chloride or phthalimide-A -sulfenyl chloride to alkenes followed by lithium aluminum hydride cleavage of the adducts (Scheme 8).13 Thiaheterocycles can also be formed by intramolecular electrophilic addition of sulfenyl chlorides to alkenes, e.g. as seen in Schemes 914 and 10.13 Related examples involving sulfur dichloride are shown in Schemes 1116 and 12.17 In the former case addition of sulfur dichloride to 1,5-cyclooctadiene affords a bicyclic dichloro sulfide via regio- and stereo-specific intramolecular addition of an intermediate sulfenyl chloride. Removal of chlorine by lithium aluminum hydride reduction affords 9-thiabicyclo[3.3.1]nonane, which can be further transformed into bicyclo[3.3.0]oct-1,5-ene.16... 

Addition of a sulfenyl chloride to an alkene in the presence of silver fluoride affords (3-fluoro sulfides, as shown in equation (2).18 The same trans adducts can also be prepared from the sulfenyl chloride adducts and silver fluoride. An alternative procedure for the formal addition of methanesulfenyl fluoride to alkenes involves the use of dimethyl(methylthio)sulfonium tetrafluoroborate and triethylamine tris(hy-drofluoride) as in equation (3).19... 

Peril uoro-fc /V-butyI methyl sulfide was synthesized by treatment of the silver derivative with trifluoromethylsulfenyl chloride. The disulfide was also obtained from initial reaction with elemental sulfur, followed by treatment with the sulfenyl chloride (Scheme 1.13).43... 

Thiazolyl sulfamic acids, rearrangement of sulfonic acid, 70 rearrangement to sulfonic acid, 75 by sulfonation, 75 2-Thiazolyl sulfenyl chloride, transformation to, thiazolyl disulfides. 412 2-Thiazolyl sulfide, in hydrocarbon synthesis, 406 oxidation of, with m-chloroperbenzoic acid, 415 with CrOj, 415 with Hj02,405,415 with KMn04,415 physical properties, infrared, 405 NMR, 404 pKa, 404 ultraviolet, 404 preparation of, from 2-halothiazoles and 5-Thiazolyl sulfides, bis-5-thiazolyl sulfide, oxidation of, 415 general, 418 5-(2-hydroxythiazolyl)phenyl sulfide case, 418 physical properties, 418 preparation of, 417-418 table of compounds, 493-496 uses of. 442 2-Thiazolyl sulfinic acid, decomposition of, 413 preparation of, from 2-acetamidothiazole sulfonyl chloride, 413 from A-4-thiazoline-2-thione and H, 0, 393,413 table of compounds, 472-473 5-Thiazolyl sulfinic add, preparation of,... 

Further examples of the preparation of fluorinated sulfides from the reaction of alkenes with sulfenyl chlorides in the presence of alkali fluorides are presented in Table 38. ... 

Bis(alkoxycarbonyl)polysulfanes (n = 3, 4) have been prepared from the sulfenyl chlorides R0C(0)8C1 with H28 (x = 1, 2) " or Na28x (v = 1, 2). " It is, however, usually observed that equation (18) does not proceed in a clean way to give the tri- or tetrasulfane in high yield but, owing to secondary interconversion reactions catalyzed by 8H compounds or sulfide ions (see 8ection 5.3), results in complex mixtures of polysulfanes R2 8 , which can be detected by L " or HPL " " (see 8ection 4). 

Lecher and his co-workers, for instance, obtained diphenyl sulfide and phenyl p-tolyl sulfide from benzene- and /Koluene-sulfenyl chloride, respectively.39... 

A different approach to long chain fluorinated sulfides is through the reactions of fluorinated sulfenyl chlorides. Such sulfenyl chlorides are available from direct chlorination of the cyclic polysulfides described above (10). Photochemical chlorination of trithiepane 8 serves to produce bis(sulfenyl) chloride 23. Both 6 (n = 4) and 6 (n = 3) give bis(sul-fenyl chloride 24 with chlorine in an inert medium without need for photoactivation. Incomplete chlorination leads to disulfur chlorides as by-products in the latter cases. 

The formation of trifluoromethyl sulfides (and other chalcogenides) from thiocyanates or disulfides, CF SiMej, and Bu NF is possible. The combination of sulfenyl chlorides. 

The involvement of sulfuranes in the reactions of organosulfur compounds is only now coming to be realized. Classic reactions such as sulfide oxidations ) and sulfenyl chloride additions to imsaturated linkages i) are claimed to involve such intermediates. The products from the reactions of... 

The reversibility of sulfenyl chloride addition allows exchange with another alkene, leading to elimination from the initial adduct. The rates of the exchange reactions vary considerably, and when an excess of an olefin that undergoes slow elimination is present with an adduct that eliminates rapidly near-quantitative exchange may occur. An appropriate exchange pair was found to be 2-chlorocyclooctyl 4-chlorophenyl sulfide (elimination half-life = 1.3 hr) and cyclopentene (elimination half-life = 400 hr) [Eq. (38)]. 

However, the thermal stability of the adducts depends on the nature of the sulfenyl chloride and on the structure of the alkenyl group. For instance, 1-chlorosilatrane (38) and alkenyl phenyl sulfides are formed by treatment of 20 or 76 with phenylsulfenyl chloride (equation 122). It is likely that the initial adducts (86 and 87), which are unstable at — 10°C, undergo elimination reaction via the formation of an episulfonium intermediate (88), followed by nucleophilic attack of Cl at silicon. In contrast, the adducts from phenylsulfenyl chloride and trialkylalkenylsilanes are thermally stable and decompose by strong bases . The larger electron-donating ability of the silatranyl group compared with the trialkylsilyl group is most probably responsible for these diffeences in stability. 

In 2006, Ranu reported on an t/ fz-Markovnikov hydro-thiolation of styrene derivatives 205 with disulfides using indium(I) iodide and ZnCl2. Whereas the proposed mechanism invoked the formation of indium(III) thiolate species, the regiochemical outcome of the reaction was opposite to that of In(III)-cataIyzed hydrothiolation of alkenes. It is, thus, reasonable to propose the in situ generation of sulfenyl chloride from ZnCl2 and diaryl sulfides followed by the formation of a thiiranium intermediate 207 that is reductively opened by Ini to give 208. This explanation corresponds to no reaction observed in the absence of either Ini or ZnCL. 

The proposed mechanism of the oxidative cleavage of S-protecting groups by the chlorosilane/sulfoxide procedure is outlined in Scheme 8. 95 The first reaction is considered to be formation of the sulfonium cation 9 from diphenyl sulfoxide (7) and the oxygenophilic silyl compound 8. The formation of a sulfonium ion of this type is known and has been utilized for the reduction of sulfoxides. 97 Subsequent electrophilic attack of 9 on the sulfur atom of the S-protected cysteine residue leads to the formation of intermediate 10, whereby the nature of the silyl chloride employed should be the main factor that influences the electrophilicity of 9. The postulated intermediate 10 may then act as the electrophile and react with another S-protected cysteine residue to generate the disulfide 11 and the inert byproduct diphenyl sulfide (12). This final step is analogous to the reaction of a sulfenyl iodide as discussed in Section 6.1.1.2.1. 

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