1-(N-Acylaminoalkyl)triphenylphosphonium salts 2a-f on reaction with DBU in MeCN are transformed into 1-(N-acylaminoalkyl)amidinium salts 3a-f. Amidinium salts 3d-f with a proton at the beta-position undergo slow tautomerization into the corresponding enamides 6d-f. The same 1-(N-acylamino)alkyltriphenylphosphonium salts 2d-fin the presence of Hunig's base are transformed directly into the corresponding enamides. Phosphonium salts 2, amidinium salts 3, and enamides 6 react with dialkyl malonates in the presence of DBU to give the corresponding amidoalkylation products. alpha-Amidoalkylation of dialkyl malonates is not observed in the presence of (i-Pr)(2)EtN, yet proceeds well under these conditions with more acidic nucleophiles, for example, phthalimide or benzyl mercaptan. (C) 2009 Elsevier Ltd. All rights reserved.