Dinuclear PdII complexes bearing mixed NHC/Py/PPh3 donor set ligands: Catalytic applications and electrochemical investigations |
| |
Authors: | Rajat Naskar Bhaskar Mondal Adhir Majumder Jayanta Bag Ramananda Maity |
| |
Institution: | Department of Chemistry, University of Calcutta, Kolkata, India |
| |
Abstract: | Bimetallic palladium(II) complexes containing classical NHC donor ligands are becoming increasingly popular owing to their various catalytic applications. However, examples of the aforementioned complexes with mixed NHC/PPh3 ligands are still rare. Bimetallic palladium(II) complexes possessing these mixed ligands are described starting from a C2-symmetric bis-imidazolium salt containing 4,4′-substituted central biphenyl ring. All the palladium(II) complexes have been tested as precatalysts in α-arylation of oxindole and Suzuki–Miyaura coupling reactions. The complex composed of mixed NHC/PPh3 donor ligands shows superior catalytic activity compared with the corresponding PEPPSI type complexes when applied in α-arylation of oxindole. The dinuclear complexes display better activity compared with the mononuclear complexes. The preliminary electrochemical measurements show the facile oxidation of PdII in the presence of combined NHC/PPh3 ligands compared with a combination of NHC/Py ligands. |
| |
Keywords: | bimetallic complexes mixed NHC/PPh3 donor ligands Suzuki–Miyaura coupling reaction α-Arylation of oxindole |
|