Synthesis, characterization and catalytic behaviour of a palladium complex bearing a hydroxy-functionalized N-heterocyclic carbene ligand

The synthesis of a new stable palladium(II) complex (3) featuring an unsymmetrical substituted N-heterocyclic carbene (NHC) ligand with a pendant hydroxy-functionalized group was successfully accomplished via transmetalation of the corresponding bis-NHC silver(I) complex (2). Solid-state structures of both 2 and 3 were determined by single-crystal X-ray diffraction. The catalytic behaviour of 3 in the direct regioselective arylation of furan and thiophene derivatives by using challenging aryl halides was studied, revealing that 3 was capable of promoting these environmentally attractive coupling reactions to afford arylated heterocycles in moderate to good yields.