V. A. Grabel’nykh

Synthesis and oxidative cleavage of poly(trimethylene diselenides)

Abstract1-Bromo-3-chloropropane and elemental selenium react in hydrazine hydrate-alkali and hydrazine hydrate-amine systems to form poly(trimethylene diselenides). The reductive cleavage of the resulting selenokols yielded 1,3-propanediselenol, 1,2-diselenolane, and bis(alkylseleno)propanes. These compounds are important reagents for organic synthesis and ligands for complex formation. The products obtained were studided by GC-MS.

Reactions of 2,3-dichloro-1-propene with sulfur and tellurium in the system hydrazine hydrate-KOH

Abstract2,3-Dichloro-1-propene reacts with sulfur dissolved in the system hydrazine hydrate-KOH (with formation of K2S2 or K2S) to afford bis(2-chloro-1-propene-3-yl)sulfide as the main product in both cases. Under similar conditions tellurium induces β-elimination of both chlorine atoms resulting in the formation of allene and complete regeneration of tellurium metal.

Features of the reaction of 2,3-dichloroprop-1-ene with selenium in a hydrazine hydrate-base systems

The direction of the reaction of sulfur with 2,3dichloro-1-propene I in the hydrazine hydrate–base system was shown to depend on the nature of the used bases. In the hydrazine hydrate–KOH system (molar ratio KOH:S = 1:1) the reaction with dichloride I affords bis(2-chloro-1-propen-3-yl)sulfide (78%) [1]. The disulfide anion generated in the system hydrazine hydrate–monoethanolamine reacts with dichloride I to give bis(2-chloro-1-propen-3-yl)disulfide (70%) [2]. Tellurium, which is reduced to the anions Теn only in the hydrazine hydrate–alkali system, reacts with 2,3dichloro-1-propene I with elimination of both chlorine atoms, and the reaction product is allene [1].

Reactions of 1,2-dihaloethanes with chalcogenide anions

Reactions of 1,2-dihaloethanes with chalcogenide anions generated from elemental chalcogens and dimethylchalcogens were performed in the hydrazine hydrate-KOH system. The use of anions Sex2− and Tex2− (x = 1−4) resulted in ethylene evolution and chalcogen regeneration (or in increased x value in an anion). Oligomers of Thiokol type formed only in the reaction of the 1,2-dichloroethane with a mixture of potassium disulfide and diselenide. The reductive cleavage of oligomers obtained in the hydrazine hydrate-KOH system followed by methylation led to the formation of 1,2-bis(methylthio)ethane, 1-methylseleno-2-methylthioethane, and 1,2-bis(methylseleno)ethane. The features of substitution with chalcogenide anions in vicinal dihalides are discussed. Mass spectra of compounds obtained were measured and analyzed.

Synthesis of unsaturated organoselenium compounds via the reaction of organic diselenides with 2,3-dichloro-1-propene in the hydrazine hydrate-KOH system

Dimethyldiselenide reacts with 2,3-dichloro-1-propene at 20–25°C in the hydrazine hydrate-KOH medium to form 2-chloro-3-methylselanyl-1-propene with 90% yield. Diphenyldiselenide in the reaction with 2,3-dichloro-1-propene, depending on the conditions, can give quite selectively four products: 2-chloro-3-phenylselanyl-1-propene, phenylselanylpropadiene, 1-phenylselanyl-1-propyne, and Z-1,2-bis(phenylselanyl)-1-propene. The effect of the selenium atom on the reaction direction and the products structure is discussed.

Domino reaction of 2,3-dichloroprop-1-ene with diphenyl disulfide in the system hydrazine hydrate-potassium hydroxide

Abstract2,3-Dichloroprop-1-ene reacted with diphenyl disulfide in the system hydrazine hydrate-potassium hydroxide at 30–35°C to give three products: 2-chloro-3-phenylsulfanylprop-1-ene, 1-phenylsulfanylpropadiene, and 1-phenylsulfanylprop-1-yne. Variation of temperature ensures selective synthesis of one of the above products, which confirms their successive formation (domino reaction). The domino reaction at 60°C goes further to afford (Z)-1,2-bis(phenylsulfanyl)prop-1-ene.

Chalcogen-containing analogs of ethylene glycol and its derivatives

Ethylene chlorohydrin when reacted with elemental chalcogens or dimethyl dichalcogenides in the hydrazine hydrate-alkali system forms chalcogen-containing analogs of ethylene glycol and its derivatives (dichalcogenated β-diglycols, chalcogenated ethanols, and chalcogenated methyl cellosolves).

Reactions of chloromethyloxirane and dihalopropanols with chalcogens in basic reducing systems

Chloromethyloxirane and 2,3-dibromopropan-1-ol reacted with a solution of selenium or tellurium in the system hydrazin hydrate-potassium hydroxide (K2Se2, K2Te2) to give allyl alcohol; the reaction was accompanied by regeneration of the initial free chalcogen. 1,3-Dichloropropan-2-ol reacted with selenium in the same system to give oligomeric product having a 2-hydroxypropane-1,3-diyldiseleno monomeric unit, while the reaction with tellurium led to the formation of allyl alcohol and almost complete regeneration of initial tellurium. Probable reaction mechanisms are discussed. Polyselenide oligomers containing a hydroxy group in a monomeric unit were formed in reactions of chloromethyloxirane and 1,3-dichloropropan-2-ol with selenium in the system hydrazine hydrate-2-aminoethanol. Under analogous conditions 2,3-dibromopropan-1-ol was converted into allyl alcohol with regeneration of elemental selenium. Reductive cleavage of polyselenide oligomers gave Se-methyl derivatives of 2-hydroxypropane-1,3-diselenol.

Features of the synthesis of unsaturated sulfides proceeding from (2-chloroprop-2-en-1-yl)isothiouronium chloride

Procedure of synthesis of sulfides containing a chloropropenyl fragment sensitive to bases was modified. The change in the sequence of reagents addition ensuring a contact of isothiouronium salt with a minimal base quantity and the application of a mixture hydrazine hydrate-alkali allowed the preparation of target sulfides under mild conditions in up to 93% yields.

Specific features of the reactions of 2,3-dichloro-1-propene with dibenzylchalcogenides in the system hydrazine hydrate-alkali

Dibenzyldisulfide and -diselenide react with 2,3-dichloro-1-propene in the system hydrazine hydrate-KOH by the domino mechanism: nucleophilic substitution of the allyl chlorine, dehydrochlorination with participation of the chlorine atom at the sp2-carbon atom, allene-acetylene rearrangement, nucleophilic addition of the chalcogenide reagent to the triple bond. The effect of the nature of the chalcogen atom and the benzyl substituent on the studied domino reaction is discussed.