Sustainable H2O/ethyl lactate system for ligand-free Suzuki–Miyaura reaction

A sustainable catalyst system consisted of H2O/ethyl lactate (EL), Pd(OAc)2 and K2CO3 has been developed as a generally applicable protocol for Suzuki–Miyaura reactions using various aryl bromides and iodides to incorporate arylboronic acids under ligand-free conditions. This protocol is advantageous owing to the employment of water and non-toxic, biomass available ethyl lactate as green media. In addition, as a co-solvent with water, ethyl lactate displayed evident superiority over conventional polar organic solvents such as DMF, DMSO and dioxane etc., which implied the additional potential function of EL as a ligand in these reactions.