A Combination of Biocompatible Room Temperature Ionic Liquid and Palladium Catalyst for Base‐ and Ligand‐Free Suzuki Coupling Reactions

Abstract A system with mild and versatile reaction conditions for a carbon–carbon bond‐forming reaction using arylboronic acids and aryl halides was developed. A readily available and biodegradable room‐temperature ionic liquid, choline hydroxide (ChOH), was combined with a ligand‐free Pd(OAc) 2 ‐catalyst, providing the corresponding symmetrical and/or unsymmetrical biaryl products in satisfactory yields under aerobic conditions. No external base or ligand was required for completion of the cross‐coupling reactions. More significantly, the reaction medium showed good recyclability, which is an important characteristic from the viewpoint of sustainable chemistry.