Schiff Base-Pd II Complexes Containing Pyridine and Thiophene Rings: Synthesis, Characterization, Suzuki-Miyaura C-C Coupling Reactions

Abstract

N ew Schiff base-palladium II complexes 1a-d were synthesized with the reaction of Schiff base ligand and [PdCl2 CH3CN 2]. Pd II complexes 1a-d were solid and stable to moisture and air. Their structures were characterized through the spectroscopic techniques including microanalysis, FT-IR, UV-Vis, proton 1H and carbon 13C NMR, mass spectrometry. The data obtained from the spectroscopic techniques showed that Schiff base-Pd II complexes 1a, 1b and 1c were formed through the coordination of azomethine nitrogen and carbonyl/hydroxyl oxygen atoms, while 1d complex coordinated only azomethine nitrogen atom of the Schiff base. All complexes were found to have square plane. In addition, Pd II complexes 1a-d were investigated in Suzuki-Miyaura coupling reactions of different aryl bromides using phenylboronic acid. The reactions were carried out in a mixed aqueous EtOH/H2O 1/3 at room temperature with K2CO3 as the base for 1 hour. The Pd II complexes 1a-d used as catalysts exhibited perfect catalytic activity in the Suzuki-Miyaura reaction

Keywords

• aryl bromides
• pd ii complexes
• schiff base
• suzuki-miyaura
• mass spectrometry.