ONO pincer type Pd(ii) complexes: synthesis, crystal structure and catalytic activity towards C-2 arylation of quinoline scaffolds

Abstract

Four new palladium(II) complexes featuring ONO pincer type hydrazone ligands were synthesized and characterized by spectroscopic and single-crystal XRD analysis. These complexes showed excellent catalytic activity towards the Suzuki–Miyaura cross coupling reaction of 2-chloroquinoline derivatives with various aryl boronic acids. The main advantages over previous methodologies include low catalyst loading, less problematic reaction media (H₂O–DMF (80 : 20%)) and a lower reaction temperature of 60 °C for optimal performance.