Synthesis of novel palladium(II) N-heterocyclic carbene complexes and their catalytic activities in the direct C5 arylation reactions

New palladium(II) N-heterocyclic carbene complexes have been easily obtained in good yields from the carbene transfer reaction of silver-NHC complexes with PdCl2(PhCN)2. These complexes were used as catalysts in the direct C5 arylation of 2-n-butylfuran, 2-n-butylthiophene and 2-n-propylthiazole with various aryl bromides.73