Deep Eutectic Solvent: An Efficient Catalyst for C-O Coupling Reactions

An efficient and facile route has been developed by using greener and reusable deep eutectic solvent (DES) for the synthesis of O-arylated ethers. This process involves nucleophilic aromatic substitution (SNAr) of various strongly electron-deficient aryl/alkyl halides and phenols with different substituents resulting in good to excellent yields of products (80-96%). A significant enhancement in the yield as well as rate of the reaction is observed with increase in presence of electron-withdrawing functionality attached to aryl halide moiety. Simplicity of this catalytic system, cheap cost and easy product isolation procedure makes this protocol economically viable and comparable to metal/ligand catalysed reactions utilizing aprotic solvents. Moreover, the other significant advantages of this method includes mild reaction conditions, short reaction times, easy work up procedure and recyclability of the catalyst up to four runs without remarkable loss in activity.