Regio- and stereoselective additions of diphenyldithiophosphinic acid to N-(1-alkynyl)amides and 1-alkynyl sulfides

Abstract

Treatment of N-(l-alkynyl)amides and 1-alkynyl sulfides with diphenyldithiophosphinic acid affords (E)-ketene N,S-acetals and S.S-acetals, respectively. The addition reactions proceed in syn fashions, which consist of protonation of the electron-rich alkynes and the following nucleophilic addition of diphenyldithiophosphinate anion to the resulting cationic intermediates. © 2008 The Chemical Society of Japan.