Catalytic and regioselective synthesis of gem- or trans-α,β -unsaturated amides by carbonylation of alkyl alkynes with aniline derivatives by palladium(II) and phosphine

The reaction of carbonylative addition of alkyl alkynes to aniline derivatives has been successfully achieved by a catalytic system formed of Pd(OAc)₂ and a suitable bidentate phosphine ligand. The reaction led mainly to gem-α,β-unsaturated amides (3) with Pd(OAc) ₂/1,3-bis(diphenylphosphino)propane/p-toluenesulfonic acid/CO as the catalytic system. However, the reaction catalyzed by Pd(OAc) ₂/1,4-bis(diphenylphosphino)butane/H₂/CO in CH ₂Cl₂ as a solvent affords trans-α,β, unsaturated amides (4) as the major product.