(IPr)Pd(pydc) (pydc = pyridine-2,6-dicarboxylate) – A highly active precatalyst for the sterically hindered C–N coupling reactions

• Novel NHC–Pd complexes with pyridine-2-carboxylate or pyridine-2,6-dicarboxylate ligand.
• Prominent reactivity in the sterically hindered C–N coupling reactions.
• Effect of ancillary ligands on catalytic activity of NHC–Pd complexes.

A new class of well-defined NHC–Pd complexes incorporating a pyridine-2-carboxylate or pyridine-2,6-dicarboxylate ligand has been synthesized. These novel complexes exhibited prominent catalytic activity in the sterically hindered C–N coupling reactions at elevated temperature, but relatively inferior reactivity at low temperature. The distinctly different reactivity of these NHC–Pd complexes was presumed to be associated with their unique structures of ancillary ligands.

A new class of well-defined NHC–Pd complexes incorporating a pyridine-2-carboxylate or pyridine-2,6-dicarboxylate ligand has been synthesized. These novel complexes exhibited prominent catalytic activity in the sterically hindered C–N coupling reactions at elevated temperature, but relatively inferior reactivity at low temperature.Figure optionsDownload as PowerPoint slide