Condensation of Lithium Diphenylphosphonium Diylides with Carbonic Anhydride Derivatives. A New One-Pot Synthesis of α,β-Unsaturated Anilides and Amidines.

Article abstract of DOI:10.1016/S0040-4039(00)79059-9

Lithium diphenylphosphonium diylides readily attack phenylisocyanate and dicyclohexylcarbodiimide.The formed semi-stabilised ylides bear a metallated amide or amidine functium.Their use in situ as Wittig reagents towards aldehydes and ketones is shown to be a new one-pot, E-stereoselective synthesis for α,β-unsaturated anilides and amidines.Moreover, the corresponding phosphonium salts were isolated.Key Words: lithium phosphonium diylides; pseudo-acylation reaction; Wittig-reaction; vinylic amides and amidines.