S. A. Rubtsova

Asymmetric synthesis of new optically active sulfinamides of menthane series and their derivatives

Asymmetric syntheses were performed of neomenthanesulfinamide in the yield of 60% and de 74%, of neomenthanesulfinaldimines and N-substituted neomenthanesulfinamides in 22–80 and 40–90% yields respectively.

New synthesis of alkane- and arylsulfonyl chlorides by oxidation of thiols and disulfides with chlorine dioxide

Sulfonyl chlorides are extensively used in the production of detergents, ion-exchange resins, elastomers, pharmaceuticals, dyes, herbicides, as semiproducts in the synthesis of sulfonic acids esters. Industrial and laboratory scale production of sulfonyl chlorides is based on reactions of aliphatic hydrocarbons with sulfuryl halides or with a mixture of sulfur dioxide and chlorine, on the oxidative chlorination of thiols, sulfi des, disulfi des; on the oxidation of sulfenyl chlorides; on the reaction of sulfonic acids and their derivatives with PCl5, COCl2, thionyl chloride, chlorine, and chlorosulfonic acid. Sulfonyl halides form also in reactions of organomagnesium compounds with sulfuryl halide or of diazonium salts with sulfur dioxide and CuCl 2 [1]. However all these methods have certain disadvantages due to the severe reaction conditions and side processes. The method of synthesis of sulfonyl chlorides we developed is convenient and simple for application, provides a high yield of the reaction product (45–82%), and does not require any special conditions for the process (heating or cooling, or high pressure). This new reaction of sulfonyl chlorides preparation previously was not described in the literature. It consists in the reaction of alkanethiols or arylthiols and disulfi des with chlorine dioxide. Chlorine dioxide is one among effi cient and available oxidants produced on the industrial scale applied to the bleaching of cellulose and disinfection of drinking water. It s well soluble in water and organic solvents, therefore it can be used in various media and allows variation in charging reagents. We formerly demonstrated that chlorine dioxide selectively oxidized sulfi des to sulfoxides [2–5] and tiols to disulfi des [6]. We used as initial compounds hexanethiol (Ia), hexadecanethiol (IIa), phenylmethanethiol (IIIa), 4-methylbenzenethiol (IVa), dibutyl disulfide (Va), diphenyl disulfi de (VIa).

Reactions of chlorine dioxide with organic compounds. Selective oxidation of sulfides to sulfoxides by chlorine dioxide

A novel method for the selective oxidation of various types of sulfides to sulfoxides using chlorine dioxide as the oxidant is proposed.

Oxidation of secondary terpene alcohols by chlorine dioxide

Secondary terpene alcohols cis- and trans-verbenol, neo-iso-verbanol, borneol, iso-borneol, and menthol were oxidized by chlorine dioxide into the corresponding ketones. It was shown that the nature of the solvent and catalyst and the structure of the starting compound, including the stereochemistry of the hydroxyl, influenced the oxidation process.

Synthesis and membranoprotective properties of new disulfides with monoterpene and carbohydrate fragments

A cooxidation of carbohydrate and terpene thiols gives mixtures of disulfides containing 51—90% of the unsymmetric product. Membranoprotective and antioxidant properties of obtained unsymmetric and symmetric disulfides were evaluated based on their ability to inhibit the H2O2-induced hemolysis of erythrocytes, as well as the accumulation of secondary products of the peroxy oxidation of lipids and the oxidation of hemoglobin.

Synthesis and asymmetric oxidation of thioglycosides derived from neomenthanethiol and α- d -galactose

Abstract6-Deoxy-6-[(1S,2S,5R)-2-isopropyl-5-methylcyclohexylsulfanyl]-1,2:3,4-di-O-isopropylidene-α-d-galactopyranose was synthesized in 94% yield from 1,2 : 3,4-di-O-isopropylidene-α-d-galactopyranose and neomenthanethiol, and its oxidation gave the corresponding diastereoisomeric sulfoxides in up to 84% yield and de values of up to 52%. The isopropylidene protective groups were removed from the sulfide and sulfoxides by treatment with trifluoroacetic acid in chloroform.

Asymmetric oxidation of hetaryl neomenthyl sulfides

Previously unknown diastereoisomeric sulfoxides were synthesized by asymmetric oxidation of 2-neomenthylsulfanyl-substituted 1H-imidazole, 1-methyl-1H-imidazole, and 1H-benzimidazole.

Functionalized mercaptoacetic and propionic acid amides: synthesis, cyclopalladation features, and catalytic activity of metal complexes

Upon treatment with thiophenol or neomenthyl mercaptane, chloroacetand propionamides with an additional Nor S-donor substituent in the amine part gave new multidentate ligands readily undergoing direct cyclopalladation in the reaction with PdCl2(NCPh)2. The realization of κ3-X, N, S-coordination (X = N, S) in the complexes obtained was confirmed by IR and NMR spectroscopy and, in some cases, by single-crystal X-ray crystallography. The evaluation of catalytic activity of the palladocycles in the Suzuki cross-coupling of aryl bromides with PhB(OH)2 allowed us to establish the principal structure—activity correlations.

Synthesis and reduction of new sulfinimines with isobornane structure

Synthesis of sulfenimines proceeding from isobornanethiol with yields up to 78% was performed. They were oxidized to diastereomeric isobornylsulfinimines and the latter were reduced to N-substituted isobornylsulfinamides in high yields.

Oxidation of polyfunctional sulfides with chlorine dioxide

Abstract3-Benzylsulfanyl-4,5-diphenyl-4H-1,2,4-triazole, 5-methylsulfanyl-1-phenyl-1H-tetrazole, 2-methylsulfanyl-1H-benzimidazole, 2-benzylsulfanyl-1H-benzimidazole, and 1-butylsulfanyl-4-nitrobenzene were oxidized to the corresponding sulfoxides with chlorine dioxide using different modes of oxidant supply. The oxidation process was characterized by high chemoselectivity.