1 -Methyl-1 - sulfenyl

Fluoro 6 chloro acetophenone see 2 Fluoro phenacyl chloride 4 Fluoro 2 chloro benzophenone see 2 Chloro phenyl 4 fluoro phenyl ketone Fluoro dichloro methyl sulfenyl chloride dichlorofluanid... 

Finally, in order to directly incorporate the nitrogen and sulphur functionalities in a single step with total stereoselectivity, the chiral allylic trichloroacetimidate 16 was treated with methyl sulfenyl triflate to give the corresponding A -sulfenyl imidate 17 in good yield. Further reaction of 17 with methyl sulfenyl triflate gave the 4,5-dihydro-l,3-oxazole 18, together with a minor amount of the trichloroacetamide 19, formed by hydrolysis of 18246. 

Chlorcarbonylsulfenylchlorid als C-S-Synthesebaustein fiihrt mit Akzeptor-substituierten Enaminen zu 2-Hydroxy-l,3-thiazolen (s. Bd. E4, S. 309f. und Lit.121 126). 2-Amino-l,3-thiazole konnen analog aus En-aminen und (Chlor-imino-methyl)-sulfenyl-chloriden gewonnen werden142 ... 

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 5-(A -methyl-N -phenylcarbamoyl)sulfenyl group (Snm group) produced under these conditions is stable to HF or CF3SO3H. Since there are few acid-stable — SH protective groups, the Snm group should prove to be useful where strong acids are encountered in synthesis. 

Tlie bifunctional sulfenyl chloride 213 was obtained by chlorination of 144 in good yield, although excessive chlorination led to the saturated compound 214 (94CB533). A series of compounds 215-220 were obtained from 213 by reactions with secondary amines ferf-butyl methyl ketone hexane-2,4-dione 2,6-dimethylcyclohexanone diethyl malonate and acetylacetone, respectively. 

Asymmetric sulfenylation. In the presence of the chiral diamine (S)-l-methyl-2-(piperidinylmethyl)pyrrolidine (1), tin(II) enolates of ketones react with... 

Sulfenyl chlorides and halogens react with 1,2-alkadienylphosphonic acids to afford phosphorus-containing heterocydes [72], However, the electrophilic addition of dialkyl 4-methyl-2,3,5-hexatrien-2-yl phosphonates with sulfenyl or selenyl chloride afforded 2-thienyl methylphosphonates or the seleno analogues [73, 74]. The conjugate addition of sulfenyl or selenyl chloride with the 2,4-diene moiety in the starting allene leads to the formation of the five-membered skeleton (Scheme 10.69). 

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... 

This indirect proof of the appearance of CF3SF leads to the conclusion that fluorination of sulfenyl chlorides of the series CF Cl3 SCl (n = 0, 1, 2) with alkali metal fluorides follows the mechanism observed in the formation of sulfenyl fluorides the initial chlorine-fluorine exchange at the sulfur atom is followed by isomerization to the sulfenyl chloride containing the corresponding more highly fluorinated methyl group. 

A chlorine-bromine exchange in fluorodichloromethanesulfenyl chloride by means of hydrogen bromide provides a route to additional sulfenyl bromides (109). After the initial halogen exchange at the sulfur, further addition of hydrogen bromide causes stepwise substitution at the methyl group ... 

The results of a comparative metabolism study of an aryl-sulfenyl derivative of carbofuran [2,2-dimethy1-2,3-dihydro-benzofuranyl-7 -methyl-N-(2-toluenesulfenyl)carbamate] in the house fly and white mouse Indicated the selective action of this compound to be a consequence of different metabolic pathways in insects and mammals (12). The arylsulfenyl group on the carbamate moiety allows the mammal to carry out metabolic reactions leading to less toxic products which are rapidly conjugated, while the toxic parent methylcarbamate is formed in the insect. 

Mercapto-l,2,4-thiadiazoles are distinctly acidic. The pK of 5-thio-3-methyl-l,2,4-thiadiazole at 25°C is 5.18 <65AHC(5)119>. The position of equilibrium in the tautomers of 5-thio-l,2,4-thiadiazoles (10) (R = H) appears to be on the thione side (11) or (12). The solid state IR spectrum of (10) (R = Ph) shows no sign of SH absorption <92PS(66)32i>. However, treatment of (10) (R = Ph, / -Tol) with diazomethane does not produce any A-methylated products, but only the 5-methyl derivatives (137) (R = Ph, /)-Tol). Methylation of (10) (R = Ph) with methyl sulfate and with methyl iodide in sodium hydroxide gives only the S-methyl derivatives (137) (Scheme 31) <92PS(66)321>. In 1989 Yousef et al. reported that (10) (R = Ph) reacted with aromatic sulfenyl chlorides and with formaldehyde to give the A-substituted products (26) and (27) (Scheme 31). At the same time, alkylation... 

Amidines are converted into 1,2,4-thiadiazoles by reaction with isothiocyanates, iminosulfenyl chlorides, di- and trichloromethyl sulfenyl chlorides, and carbon disulfide in the presence of sulfur <82AHC(32)285> for example, 5-mercapto-3-methyl-l,2,4-thiadiazole (205) is obtained by the treatment of acetamidine with carbon disulfide and sulfur under basic conditions (Equation (29)) <85JAP85255783>. A useful method for the synthesis of 5-chloro-l, 2,4-thiadiazole (206) (R = 6-methyl-2-pyridyl) involves the reaction of amidines with trichloromethylsulfenyl chloride (Equation (30)) <91JAP9183590>. 

An alternative method for formation of trisulfides1 0 has been derived from well-known procedures for the formation of disulfides that involve sulfenyl thiocarbonates as protecting/ activating groups for cysteine 25 In analogy to the chemistry for disulfides, cysteine side chains were protected and activated as extra-sulfur analogues, i.e. as S-(methoxy-carbonyl)disulfanyl or S-(/V-methyl-/V-phenylcarbamoyl)disulfanyl derivatives 10 Preferably,... 

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