The addition of acetanilides to ethyl propiolate proceeds under neutral conditions in the presence of triphenylphosphine to give the corresponding alpha-substituted alkyl acrylates together with variable amounts of the beta-substituted isomer with (E) geometry. Addition of arylsulfonylanilides to alkyl propiolates under similar conditions, produced only the alkyl (E)-3-arylsulfonylanilino-2-propenoates. (c) 2006 Elsevier B.V. All rights reserved.