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A mechanism has been proposed for the reaction of 1,3-dichloropropene with dipotassium propane-1,3-bis(dithiolate) in the system hydrazine hydrate–potassium hydroxide on the basis of DFT quantum chemical calculations at the B3LYP/6-311++G(d,p) level of theory. The first stage of this reaction has been found to be nucleophilic substitution of one chlorine atom of 1,3-dichloropropene linked to the sp3-carbon atom by the sulfur atom of propane-1,3-bis(thiolate) to give the corresponding monosubstitution product. Further transformations of the latter could lead to the formation of six-, seven-, and eight-membered sulfur heterocycles, as well as of a linear structure as a result of reaction of the monosubstitution product with the second 1,3-dichloropropene molecule. [ABSTRACT FROM AUTHOR]

A possibility of the synthesis of 1,4-dichalcogenins by the reaction of vinylidene chloride or 1,2-dichloroethene with elemental chalcogenes in a hydrazine hydrate–KOH system was studied. When vinylidene chloride was used, the maximum yield of 1,4-diselenin was 38%; 1,4-ditellurine was not formed. Diselenin was obtained from 1,2-dichloroethene in 45% yield, while ditellurine was prepared in 21% yield. A plausible mechanism for the formation of dichalcogenin molecules was proposed, which makes it possible to explain the differences in the behavior of 1,1- and 1,2-dichloroethenes in the reaction with potassium telluride. When two chalcogenes were introduced into the reaction, 1,4-dichalcogenins with different chalcogen atoms were obtained with yields of up to 7%. [ABSTRACT FROM AUTHOR]

Electron-donor effect of the methyl group in 1,3-dichlorobut-2-ene hampers allylic rearrangement of its primary monochalcogenation products. The use of diphenyl disulfide under harsh conditions (Ph2S2-KOH, 1: 10, 75-80°C) makes it possible to obtain a mixture of six bis(phenylsulfanyl)butenes, 1,1-bis(phenylsulfanyl) but-1-ene being the major component. No bis(phenylselanyl) derivatives have been formed on heating up to 80°C. Dipotassium ethane-1,2-dithiolate reacts with 1,3-dichlorobut-2-ene to give a linear product of chlorine substitution at the sp3-carbon atom in two dichlorobutene molecules and a heterocyclic compound, 2-ethylidene-1,4-dithiane (a mixture of E and Z isomers), whose structure is different from the structure of the product obtained from 1,3-dichloropropene under analogous conditions. Mechanisms have been proposed for the formation of the isolated compounds. [ABSTRACT FROM AUTHOR]

Vinylidene chloride and 1,2-dichloroethene react with sulfur in the system hydrazine hydrate-KОН with the formation of polyvinylenesulfide oligomer of molecular mass 1750-6120 Da containing also vinylenehydrazine and vinylenechloride links in the Z-configuration, and 1,4-dithiine in the yield up to 46%. In aqueous-hydrazine layer polysulfide anions Sn2- (n = 1-4), mainly S22- were found. The mechanism of formation of oligomers and 1,4-dithiine is suggested, which includes in the first stage dehydrochlorination of dichloroethenes and generation of chloroacetylene. [ABSTRACT FROM AUTHOR]

Reaction of 1,1- and 1,2-dichloroethenes with PhS, PhSe, BnS, and i-PrS in a system hydrazine hydrate-KOH proceeds as a sequence of successive transformations: dehydrochlorination of initial dichloroethenes to form chloroacetylene, chlorine substitution for the chalcogen-containing nucleophile (ethynylchalcogenides formation), and the addition of the nucleophilic reagent to the triple bond affording 1,2- dichalcogenylethenes. In reactions with PhS and PhSe nucleophiles due to the high rate of all stages 1,2-bis (phenylchalcogenyl)ethenes are obtained having mainly the Z-configuration. In reactions with BnS and i-PrS in the IR, NMR and chromato-mass spectra intermediate ethynylchalcogenides were identified, and the final products consisted of a mixture with the prevalence of the Z-isomer. [ABSTRACT FROM AUTHOR]

Sulfur reacts with 1,3-dichloropropene in the system hydrazine hydrate-KOH to form bis(1-chloroprop-1-en-3-yl) sulfide, and in the system hydrazine hydrate-monoethanolamine, bis(1-chloroprop-1-en- 3-yl) disulfide. The reaction of tellurium in the system hydrazine hydrate-KOH leads to diallyl telluride, the product of nucleophilic substitution of the allylic chlorine atom and reductive cleavage of the С-Cl bond. The reaction of selenium with 1,3-dichloropropene gives a complex mixture of products. At excess KOH (Se: KOH = 1: 5) bis(1-chloroprop-1-en-3-yl) selenide was isolated. [ABSTRACT FROM AUTHOR]