Selenium- and tellurium-containing binucleophiles in selective synthesis of allene and methylacetylene from 2,3-dichloro-1-propene

Abstract

Recently, we have shown that pure allene is formed in the reaction of K2Te2 with 2,3-dichloro-1-propene (I) in the hydrazine hydrate – KOH medium [2]. In the case of Se analog (K2Se2), the reaction with compound I does not yield any gaseous products but rather gives bis(2-chloro-1-propene-3-yl)selenide [3]. Extending the studies of chalcogen-containing nucleophiles reactions with I, we here report on the behavior of binucleophilic reagents, potassium 1,3-propaneditellurolate (IIа) and potassium 1,3-propanediselenolate (IIb). Compounds IIа and IIb were prepared by reductive decomposition of the respective poly(trimethylenedichalcogenides) [4, 5] in the hydrazine hydrate–KOH medium. The so obtained salts IIа and IIb were introduced in the reaction with I without isolation.