Formation of novel 1 : 2 adducts between Bun3P·CS2 and electron-deficient alkynes
Abstract
The zwitterionic adduct between tri-n-butylphosphine and carbon disulphide reacts under neutral conditions with two equivalents of dimethyl and diethyl acetylenedicarboxylate, dibenzoylacetylene and methyl benzoylpropiolate to give novel crystalline dithiole-containing ylides whose structure is established by X-ray crystallography.