ON THE REACTION OF METALLATED ACETYLENES AND ALLENES WITH CARBON DISULFIDE. INFLUENCE OF THE ALKALI METAL COUNTER-ION AND THE SUBSTITUENTS IN THE ACETYLENE AND ALLENE ON THE COURSE OF THE REACTION

Article abstract of DOI:10.1016/0022-328X(86)80313-8

Addition at low temperatures of carbon disulfide to a solution of the lithium compound (R¹ = CH3, C3H7, Ph, OCH3, SCH3) results in the initial formation of an allenic carbodithioate H2C=C=C(R¹)CSSLi, while for R¹ = t-C4H9 or SiMe3 acetylenic carbodithioates R¹C<*>CCH2CSSLi are formed.The initial products undergo very rapid subsequent reactions.For R¹ = CH3 or C3H7 the lithium compound adds (in the allenic form) in a conjugated fashion to the C=C-C=S system of the allenic carbodithioate.The acetylenic dithioates are deprotonated to give the geminal dithiolates R¹C<*>C-CH=C(SLi)2.For R¹ = Ph, OCH3 or SCH3, subsequent deprotonation at the terminal carbon atom of the initial allenic dithioate gives enyne dithiolates HC<*>C-C(R¹)=C(SCH3)2; this reaction proceeds more satisfactorily with the potassium compounds.