Sulfonates and Sulfinates

There are many parallels between phosphates and sulfates of aliphatic alcohols. Both types of surfactants contain ester bonds undergoing hydrolysis in acid solutions. In that case the starting materials are received once more. By dry heating of the salts above a temperature of 140°C destruction will occur forming the corresponding alkenes and an inorganic acid salt. In the same way as sulfonic and sulfinic acids are formed by C-S bonds, C-P bonds lead to phosphonic and phosphinic acids. 

Table 21-1. Halides prepared from alcohols via imidazole-V-carboxylates, -sulfonates and -sulfinates.

Bicarbonate washing ensures removal of the sulfonic and sulfinic acids. 

Further oxidation and hydrolysis of diethyl disulfide to sulfonic and sulfinic acids do not occur when the reaction proceeds in aqueous solvents (13,22). 

Sulfonic acids are prepared on a commercial scale by the sulfonalion of organic substrates using a variety of sulfonating agents, including sulfur trioxidc (diluted in air), sulfur trioxide (in sulfur dioxide), sulfuric acid, oleum (fuming sulfuric acid), chlorosulfuric acid, sulfamic add, trialkylamine-sulfur trioxide complexes, and sulfite ions. Other methods of sulfonic acid production, practiced on an industrial scale, include the oxidation of thiols, sulfide, disulfides, sulfoxides, sulfones, and sulfinic acids. See also Sulfonalion and Sulfation. 

Reduction of Sulfonic and SulFinic Acids and Their Derivatives... 

TABLE 11.2 Sulfonic and Sulfinic Acid-Based Photoinitiators and Corresponding Initiating Species Generated upon Photolysis. 

Methanesulfonic acid added to an ice-cooled soln. of 5-benzyloxy-l,2-epoxy-4-hydroxy-3-methylhexyl N,N-diisopropylcarbamate in methanol, the mixture stirred at 20-5° for 15 h, and treated with triethylamine methyl 5-0-benzyl-3,6-dideoxy-3-C-methyl-P-L-allofuranoside. Y 84%. F.e.s. D. Hoppe et al.. Synthesis 1989, 83-8 preparation of C- and C-labelled methane-sulfonic and -sulfinic acid s. V.J. Feil et al., J. Labelled Compds. Radiopharm. 25, 1021-5 (1988). 

Mekhalif et al. [160-162] studied the formation and structure of alkanethiol SAMs on nickel, comparing cleaned/polished substrates with others that underwent additional electrochemical pretreatment to remove surface oxide. Polycrystalline Ni disks were mechanically polished with diamond paste and rinsed with acetone and ethanol. The additional electrochemical pretreatment consisted of 20 min reduction in 1 M HCIO4 at 0.7 V versus SCE. Exposure time to the atmosphere prior to self-assembly was less than 3 s. Samples that were not electrochemically treated produced poor quality SAMs, with considerable part of the thiolates oxidized to sulfonates and sulfinates [160, 162]. 

Chemical Shifts of Sulfonic and Sulfinic Acids and Derivatives (5 in ppm relative to TMS)... 

Sulfonyl and Sulfinyl Chlorides from Sulfonic and Sulfinic Acids. Alkyl or arylsulfonyl chlorides are prepared by heating the acid with thionyl chloride DMF catalyzes this reaction. (+)-Camphorsulfonyl chloride is produced in 99% yield without a catalyst. Use of the salts of sulfinic acids minimizes their oxidation p-toluenesulfinyl chloride is produced in about 70% yield from sodium p-toluenesulfinate dihydrate with excess thionyl chloride. Phosphorus(V) Chloride is more commonly used for this transformation. 

---