Palladium-Catalyzed Regioselective Hydroaminocarbonylation of Alkynes to α,β-Unsaturated Primary Amides with Ammonium Chloride

α,β-Unsaturated primary
amides have found numerous
applications in drug development, organic materials, and polymer sciences.
However, the catalytic synthesis of α,β-unsaturated primary
amides via carbonylation of alkynes has long been an elusive endeavor.
Here, we report a novel palladium-catalyzed hydroaminocarbonylation
of alkynes with NH4Cl as the amine source, enabling the
highly chemo- and regioselective synthesis of α,β-unsaturated
primary amides. A variety of alkynes, including aromatic alkynes,
aliphatic alkynes, terminal alkynes, internal alkynes, as well as
diynes with various functional groups, react well. The method turns
the parasitic noncoordination ability of ammonium salts into a strategic
advantage, enabling the gram-scale reaction to be performed in the
presence of 0.05 mol % of catalyst with excellent selectivity