Organic reactions in excess water catalyzed by solid acids

Abstract

A solid acid, Cs 2.5H 0.5PW 12O 40, efficiently catalyzed the reactions in which water participates such as hydrolysis of ester, hydration of alkene, and esterification, in excess water. This acidic salt was far superior in the activity to other oxide catalysts such as H-ZSM-5, Nb 2O 5, SO 2− 4/ZrO 2, and SiO 2–Al 2O 3. When Cs 2.5H 0.5PW 12O 40 was separated from the reactant solution and reused five times for the hydrolysis of ethyl acetate repeatedly, the reaction rate was retained more than 90%. These results demonstrates that Cs 2.5H 0.5PW 12O 40 is an efficient water-tolerant solid acid.