Co-Catalysis for Hydroamidocarbonylation of Alkynes with Amides over a Bifunctional Ligand-Based Pd Catalyst

Graphical The hydroamidocarbonylation of alkynes with amides was accomplished over a bifunctional ligand based Pd catalyst. The hydroamidocarbonylation of alkynes with amides allows for the synthesis of α,β-unsaturated imides with the advantage of 100% atomic economy. Herein, the bifunctional ligand ( L1 ) containing a sulfonic acid group (-SO 3 H) and phosphino-fragment enable the Pd catalyst to accomplish the hydroamidocarbonylation of alkynes with amides. It was found that, due to an intramolecular synergetic effect, the L1 -based Pd-catalyst exhibited much higher activity than the individual mechanical mixtures of Xantphos-based Pd-complex and MeSO 3 H. The formation and stability of Pd-H species were promoted by the presence of L1 , which was verified by in situ high-pressure FT-IR analysis. Under the optimized conditions, the target products of the branched imides were obtained with yields in the range of 46–87% over the L1 -based Pd-catalyst. Advantageously, as an ionic ligand, the L1 -based Pd-catalyst could be recycled for 4 runs in the ionic liquid of [Bmim]NTf 2 without any obvious activity loss and detectable metal leaching.