α,β-Unsaturated primary amides are important intermediates and building blocks in organic synthesis.Herein,we report a ligand-free iron-catalyzed hydroaminocarbonylation of alkynes using NH_(4)HCO_(3)as the ammonia source,enabling the highly efficient and regioselective synthesis of linearα,β-unsaturated primary amides.Various aromatic and aliphatic alkynes are transformed into the desired linearα,β-unsaturated primary amides in good to excellent yields.Further studies show that using NH_(4)HCO_(3)as the ammonia source is key to obtain good yields and selectivity.The utility of this route is demonstrated with the synthesis of linearα,β-unsaturated amides including vanilloid receptor-1 antagonist TRPV-1.
