Stereoselective Synthesis of Enamides by Pd-Catalyzed Hydroamidation of Electron Deficient Terminal Alkynes

Hydroamidation of electron-deficient terminal alkynes by amides in presence of Pd catalyst has been exploited for the stereoselective synthesis of Z-enamides. The possible intramolecular hydrogen bonding between the amido proton and carbonyl oxygen of ester group provides the extra stability to the Z-isomer of vinyl palladium complex, which subsequently undergoes protodepalladation and leads to the Z-enamide selectively. This process is found to be mild and operationally simple with broad substrate scope.