Abstract
Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and alkyl acetylenecarboxylates by phenothiazine, leads to vinyltriphenylphosphonium salts, which undergo a Michael addition reaction with conjugate bases to produce the corresponding phosphorus ylides. The phosphorus ylides react with water forming phenothiazine containing diphenylphosphine oxide derivatives in moderate yields.
The authors are thankful to the Islamic Azad University–Zanjan Branch and Payam Noor University (PNU), Abhar Center for partial support of this work.