Sulfenyl chloride
A sulfenyl chloride is a functional group with the connectivity R–S–Cl, where R is alkyl[1] or aryl. Sulfenyl chlorides are reactive compounds that behave as sources of RS+. They are used in the formation of RS–N and RS–O bonds. According to IUPAC nomenclature they are named as alkyl thiohypochlorites, i.e. esters of thiohypochlorous acid.
Preparation[edit]
Sulfenyl chlorides are typically prepared by chlorination of disulfides:[2][3]
- R2S2 + Cl2 → 2 RSCl
This reaction is sometimes called the Zincke disulfide reaction, in recognition of Theodor Zincke.[4][5] Typically, sulfenyl halides are stabilized by electronegative substituents. This trend is illustrated by the stability of CCl3SCl obtained by chlorination of carbon disulfide.
Reactions[edit]
CCl3SCl reacts with N-H-containing compounds in the presence of base to give the sulfenamides:
- CCl3SCl + R2NH → CCl3SNR2 + HCl
This method is used in the production of the fungicide captan.
Sulfenyl chlorides add across alkenes:[6]
- CH2=CH2 + RSCl → RSCH2CH2Cl
They undergo chlorination to the trichlorides:[3]
- CH3SCl + Cl2 → [CH3SCl2]Cl
Related compounds[edit]
Sulfenyl bromides are also known.[7] Simple sulfenyl iodides are unknown because they are unstable with respect to the disulfide and iodine:
- 2 RSI → (RS)2 + I2
Sulfenyl iodides can be isolated as stable compounds if they bear alkyl steric protecting groups as part of a cavity-shaped framework, illustrating the technique of kinetic stabilization of a reactive functionality, as in the case of sulfenic acids.[8]
A related class of compounds are the alkylsulfur trichlorides, as exemplified by methylsulfur trichloride, CH3SCl3.[9]
The corresponding selenenyl halides, e.g. C6H5SeCl, are more commonly encountered in the laboratory. Sulfenyl chlorides are used in the production of agents used in the vulcanization of rubber.
References[edit]
- ^ Drabowicz, J.; Kiełbasiński, P.; Łyżwa, P.; Zając, A.; Mikołajczyk, M. (2008). Kambe, N., ed. Alkanesulfenyl Halides. Science of Synthesis. 39. pp. 544–550. ISBN 9781588905307.
- ^ Hubacher, Max H. (1943). "o-Nitrophenylsulfur chloride". Org. Synth.; Coll. Vol., 2, p. 455
- ^ a b Methanesulfenyl chloride: Douglass, Irwin B.; Norton, Richard V. (1973). "Methanesulfinyl Chloride". Org. Synth.; Coll. Vol., 5, pp. 709–715
- ^ Zincke, Th. (1911). "Über eine neue Reihe aromatischer Schwefelverbindungen". Chemische Berichte. 44 (1): 769–771. doi:10.1002/cber.191104401109.
- ^ Zincke, Th.; Farr, Fr. (1912). "Über o-Nitrophenylschwefelchlorid und Umwandlungsprodukte". Justus Liebig's Annalen der Chemie. 391 (1): 57–88. doi:10.1002/jlac.19123910106.
- ^ Brintzinger, H.; Langheck, M., "Synthesen mit Alkylschwefelchloriden (X. Mitteil. über organische Schwefelchloride)", Chemische Berichte 1954, volume 87, 325-330. doi:10.1002/cber.19540870306
- ^ Reno, Daniel S.; Pariza, Richard J. (1998). "Phenyl Vinyl Sulfide". Org. Synth.; Coll. Vol., 9, p. 662
- ^ Sase, S.; Aoki, Y.; Abe, N.; Goto, K. (2009). "Stable Sulfenyl Iodide Bearing a Primary Alkyl Steric Protection Group with a Cavity-shaped Framework". Chemistry Letters. 38 (12): 1188–1189. doi:10.1246/cl.2009.1188.
- ^ Braverman, S.; Cherkinsky, M.; Levinger, S. (2008). "Alkylsulfur Trihalides". Sci. Synth. 39: 187–188. ISBN 9781588905307.
