Lewis Acid Catalysis in Clean Solvents, Water, and Supercritical Carbon Dioxide

摘要

New types of Lewis acids as water-compatible catalysts have been developed. Metal salts such as rare earth metal triflates were found to work as Lewis acids in carbon―carbon bond-forming reactions in the presence of large amounts of water. These salts can be recovered after the reactions and reused. Furthermore, Lewis acid―surfactant-combined catalysts, which can be used for reactions in water without using any organic solvents, have been also developed. Finally, Lewis acid catalysis in supercritical carbon dioxide has been successfully performed. These investigations will contribute to reducing use of harmful organic solvents and to development of environmentally friendly Lewis acid catalysis.