A simple synthesis of stable phosphorus ylides containing cyano groups, from the reaction between triphenylphosphine and acetylenic esters in the presence of CH- acid compounds

Abstract

Stable crystalline phosphorus ylides were obtained in excellent yields from the 1:1:1 addition reaction between triphenylphosphine and dialkyl acetylenedicarboxylates, in the presence of strong CH- acids such as malononitrile or ethyl cyanoacetate. These stable ylides exist in solution as a mixture of two geometrical isomers as a result of restricted rotation around the carbon-carbon partial double bond resulting from conjugation of the ylide moiety with the adjacent carbonyl group. ©ARKAT-USA, Inc.