An Efficient One-Pot Synthesis of Sulphur-Containing Phosphorus Ylides

Abstract

Protonation of the reactive 1:1 intermediate produced in the reaction between dialkyl acetylenedicarboxylates and triphenylphosphine by arylsulfonamides leads to vinylphosphonium salts, which undergoes Michael addition with the conjugate base of the NH-acid to produce highly functionalized, salt-free phosphorus ylides in good yields. These stable ylides exist 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.

Key Words:

• Acetylenic esters
• arylsulfonamides
• NH-acids
• stabilized ylides
• triphenylphosphine