Palladium(II) acetate catalyzed efficient synthesis of N-aryl-α,β-unsaturated amides via carbonylative addition of aniline derivatives to aromatic alkynes

A series of new N-arylα,β-disubstituted amides (gem or E1; trans or E2) were synthesized in good yields by carbonylative addition of aniline derivatives 1a-f to aromatic alkynes 2a,b catalyzed by Pd(OAc)₂ and 1,3-bis(diphenylphosphino)propane. The catalytic synthesis of tertiary α,β-unsaturated amides was also successfully achieved. Traces of products were observed in the absence of p-toluenesulfonic acid used as an additive. The reaction is sensitive to the type of phosphine ligand and solvent.