Synthesis, structure determination of Schiff bases and their PdII complexes and investigation of palladium catalyzed cross-coupling reactions

Abstract

Two Schiff base ligands, S1 and S2, were synthesized from the reaction of 2-amino-5-ethyl-4-methylthiophene-3carbonitrile with 2-hydroxybenzaldehyde and 4-nitrobenzaldehyde were investigated for their coordination to PdCl2(CH3CN)2. The prepared ligands S1 and S2 and the PdII complexes 1 and 2 were characterized by using FTIR, 1H-13C NMR, UV-Vis, TGA, elemental analysis, molar conductivity, mass, and magnetic susceptibility. The characterization data agree well with the formulation of ligands S1 and S2 and PdII complexes 1 and 2. The geometries of the metal chelate were discussed with the help of magnetic and spectroscopic measurements. Finally, the catalytic potential of the synthesized PdII complexes for Suzuki-Miyaura and Mizoroki-Heck coupling reactions was investigated using GC-MS. As a result, it was observed that the PdII complexes are the active catalysts in suitable Suzuki-Miyaura and Mizoroki-Heck C-C coupling reactions.