Synthesis of a N‐heterocyclic Olefin‐Ligated Pd Complex [(NHO)Pd{[2‐(CH3O)C6H4]3P}Cl2] as a Catalyst for Suzuki−Miyaura Coupling

Abstract

AbstractN‐heterocyclic olefin (NHO) is known as a highly electron‐donative ligand, but its application to metal catalysts has rarely been studied. In this study, we synthesized 2‐methyleneimidazolidine ligands equipped with a bicyclic frameworks with the goal of developing a NHO‐ligated Pd catalyst. These synthesized [(NHO)PdCl(μ‐Cl)]2 complexes had a phosphine co‐ligand that proved effective as a catalyst for Suzuki‐Miyaura coupling at ambient temperature. By optimizing the N‐substituents of NHO ligands and a phosphine co‐ligand, we developed a [(NHO)Pd{[2‐(CH3O)C6H4]3P}Cl2] complex as a catalyst that shows good catalytic activity.