Aluminium-catalysed synthesis of aryl enol ethers from phenols and dimethyl ketals

We report an environmentally friendly, aluminium-catalysed, halide- and transition metal-free method for the synthesis of aryl enol ethers from phenols and dimethyl ketals that involves ketal exchange driven by the removal of methanol. The obtained aryl enol ethers were transformed into the corresponding diaryl ethers by Pd/C-catalysed dehydrogenation or DDQ oxidation. We have developed a new halide- and transition metal-free protocol for the synthesis of aryl enol ethers from phenols and dimethyl ketals, which are important intermediates or building blocks in organic synthesis and polymer chemistry.