Reaction of diphenyl ditelluride with 2,3-dichloroprop-1-ene in the system hydrazine hydrate-KOH

Diphenyl ditelluride reacts with 2,3-dichloroprop-1-ene in the system hydrazine hydrate-KOH along several parallel routes. Beside the nucleophilic chlorine substitution at the sp ³-hybridized carbon atom resulting in 2-chloro-3-phenyltellanylprop-1-ene the elimination of both chlorine atoms occurs affording a mixture of allene and methylacetylene. The reasons of the dual elimination reaction paths are considered.     

Effect of the chalcogen nature on the reaction of propane-1,3-dichalcogenolates with 2,3-dichloroprop-1-ene

The direction of the reaction of propane-1,3-dichalcogenolates with 2,3-dichloroprop-1-ene in the system hydrazine hydrate-KOH depends not only on the conditions but to a greater extent on the chalcogen nature. Dipotassium propane-1,3-dithiolate and propane-1,3-diselenolate give rise to products of substitution of the chlorine atom on the sp ³-carbon atom, which are capable of undergoing further transformations (domino reaction). Dipotassium propane-1,3-ditellurolate promotes elimination of both chlorine atoms with formation of allene.     

Reaction of Aldehydes with Hydrazine in the System Sulfur-Alkali

Dissolution of sulfur in the system hydrazine hydrate-alkali leads to strong activation of hydrazine, so that the latter readily reacts at room temperature with aldehydes of the aromatic and thiophene series to give the corresponding aldehyde azines in high yield. The mechanism of activating effect of sulfur is discussed.     

REACTION OF (ORGANYLTHIO)CHLOROACETYLENES WITH ALIPHATIC 1,2-DITHIOLS: A ROUTE TO FUNCTIONALIZED 1,3-DITHIOLANES

(Organylthio)chloroacetylenes react with aliphatic 1,2-dithiols in dimethyl sulfoxide at 20–25°C in the presence of a two-fold molar excess of alkali to form 2-[(alkylthio)methyliden]-1,3-dithiolanes in up to 66% yield.     

New ways of synthesis of 1,2-dithiole-3-thione

Two new synthetic approaches to 1,2-dithiole-3-thione are proposed. The title compound is formed by thermolysis of dipropyl polysulfides (n-Pr)₂S_x (x = 3–4) and thermal decomposition of polysulfide dendrimers under reduced pressure. The latter reaction may be recommended for utilization of organochlorine waste products in the manufacture of epichlorohydrin, which are used for the synthesis of dendrimers.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 11, 2004, pp. 1884–1886.Original Russian Text Copyright © 2004 by Korchevin, Russavskaya, Yakimova, Deryagina.This revised version was published online in April 2005 with a corrected cover date.     

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.     

Reactions of Bielectrophiles (ClCH2CH2)2Y with Sulfur in Basic Reducing Systems

A simple procedure was developed for preparing bis(-mercaptoethyl) ether and bis(-ecraptoethyl) sulfide from commercially available chemicals: elemental sulfur, alkali, and bis(-chloroethyl) ether or sulfide, based on thiylation with elemental sulfur of these substrates in the aqueous system hydrazine hydratealkali, with initial formation of the corresponding polysulfide polymers (thiokols). Their reduction with the system hydrazine hydrate-alkali, followed by acidification of dithiolate anions, yields the corresponding dithiols. Thiokols based on bis(-chloroethyl) ether are soluble in organic solvents; they were studied by ¹H NMR.     

Synthesis of polydentate chalcogen-containing ligands using the system hydrazine hydrate–base

The reaction of dichlorodiethyl ether or dichlorodiethylamine hydrochloride with potassium or ethanolammonium dichalcogenides prepared in situ from elemental sulfur or selenium in the system hydrazine hydrate–alkali results in oligomeric dichalcogenides, whose further splitting at the chalcogen–chalcogen bond in the same system and subsequent alkylation affords bis(organylsulfanyl)- or bis(organylselanyl)-substituted derivatives of diethyl ether or diethylamine. Ligands with aryl substituents at the chalcogens have been prepared in 48-59% yield by splitting of diaryldichalcogenides in the system hydrazine hydrate–alkali and subsequent reaction with dichlorodiethyl ether or dichlorodiethylamine. A ditopic tetradentate ligand has been synthesized by the use of dichlorodiethylformal.