Promoted Zirconia Solid Acid Catalysts for Organic Synthesis

This review deals with the catalytic performance of sulfate, molybdate and tungstate ion promoted zirconia solid acid catalysts for various acid-catalyzed organic synthesis and transformation reactions in the liquid phase. These promoted zirconia catalysts exhibit superacidity which mainly depends on the preparation conditions. In particular, the sulfated zirconia catalyst exhibits very strong solid acidity and excellent catalytic activity not only for simple acylation, condensation and esterification reactions but also for other important reactions such as synthesis of aromatic gem-dihalides, stereocontrolled glycosidation, regioselective ring opening of aziridines, production of diaryl sulfoxides and so on. Molybdate and tungstate promoted zirconia catalysts that also exhibit good catalytic activity for various organic reactions of practical importance.