Lim, Meilin

N-Heterocyclic Carbenes (NHCs) have significantly impacted organometallic chemistry as ligands in transition metal catalysis, offering strong electron-donating properties and high bond dissociation energies. However, their structural versatility is limited by the scarcity of commercial precursors and challenging modification procedures. Furthermore, we have investigated its coordination to transition metals; copper, silver, and palladium. We further demonstrate the effects of its steric parameters by utilizing the Suzuki-Miyaura cross-coupling of aryl chlorides using [(RO-NHC)Pd(allyl)Cl] as precatalysts. This study demonstrates increased catalyst activity with bulkier ligands in Suzuki-Miyaura cross-coupling reactions. We also present simplified procedures for copper NHC complexes using triethylamine with no requirements for special equipment and techniques. Preliminary investigations towards a more economical approach to measuring the electron donating abilities of NHCs were conducted using CuI and AgI cyanide complexes as probes. The outcomes of this research may contribute to the growing research in the applications of NHCs as ligands in catalysis.

Author Keywords: Catalysis, Ligand synthesis, N-Heterocyclic carbenes, Organic Chemistry, Organometallic Chemistry, Transition metal catalysis