Abstract
M.Sc. (Chemistry)
Novel water-soluble cationic Pd(II) SNS pincer complexes have been successfully synthesized and investigated in detail for their catalytic activity in cross-coupling reactions. Treatment of in situ generated thiolate with 2,6-bis(chloromethyl)pyridine gave ligands L1-L4. Complexation of these sulfur based ligands L1-L4 with [PdCl2(MeCN)2] as a metal precursor gave the corresponding water-soluble cationic Pd(II) SNS pincer complexes C1-C4 and intermediates bidentate SN-Pd(II) complexes C1I and C4I. These ligands and their corresponding complexes were characterized using nuclear magnetic resonance spectroscopy, infrared spectroscopy, single crystal X-ray diffraction (for complex C3), mass spectrometry and elemental analysis.
Complexes C1-C4 were then evaluated as pre-catalysts in Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions. For the Suzuki-Miyaura reaction, the coupling of inactivated aryl bromides and activated aryl chlorides with various boronic acids in water was achieved...