A convenient procedure for the synthesis of Z-bis(alkylthio)ethenes
Z-Bis(methylthio) and Z-bis(ethylthio)ethene have ben prepared in ~80% yields by successively adding Z- or E-1,2-dichloroethene (one mol equiv.), and absolute ethanol to a mixture of sodamide (two mol equivalents) and sodium alkanethiolate (two mol equiv.) in liquid ammonia.
Formation of symmetrical alkenes by homocoupling of metallated sulfones under nickel catalysis
Summary -Allylic sulfones undergo a coupling reaction with organometallic compounds (Mg or Li) not only with copper catalysts but also with iron or nickel salts. With 7,7-disubstituted allylic sulfones and also saturated aliphatic sulfones, however, another reaction was observed whereby two molecules of the starting sulfone are coupled to give symmetrical alkenes. The scope of this reaction was investigated. Elsevier.
PHOTOCHEMICAL REACTIONS OF 2-BORNANETHIONE (THIOCAMPHOR) WITH BIS(METHYLTHIO)ETHYNE. ADDITION AND INTRAMOLECULAR HYDROGEN ABSTRACTION
Irradiation of a mixture of bornanethione 7 and bis(methylthio)ethyne 2a afforded a mixture of methyl E- and Z-2-(2-bornylidene)-2-(methylthio)ethanedithioate 8 and E-1,2-bis(methylthio)vinyl 2-bornen-2-yl sulfide 10E.The first compounds are the products of the (2+2)-photocycloaddition reaction between bornanethione 7 and acetylene 2a.The sulfide 10E is rationalised as being the product of an intramolecular H abstraction reaction of the 1,4-biradical 12 which is also believed to be the intermediate in the (2+2)-cycloaddition reaction.