Pd(ii) complexes with mixed benzothiazolin-2-ylidene and phosphine ligands and their catalytic activities toward C–C coupling reactions

Abstract

Novel Pd(II) mixed N,S-heterocyclic carbene (NSHC)-phosphine complexes of the general formula [PdBr₂(NSHC)(PR₃)] were obtained from bridge cleavage of dinuclear NSHC complexes of type [PdBr₂(NSHC)]₂ [NSHC = 3-benzylbenzothiazolin-2-ylidene and 3-propylbenzothiazolin-2-ylidene] with triphenylphosphine, tricyclohexylphosphine and 2-diphenylphosphanyl-pyridine. All complexes have been fully characterized by ¹H and ¹³C NMR spectroscopy, ESI mass spectrometry and elemental analysis. The X-ray crystal structures of complexes 3–8 are reported. The complexes exhibit moderate to good catalytic activity in the Suzuki–Miyaura coupling reaction of aryl bromides and chlorides.