Highly Efficient Indirect Hydration of Olefins to Alcohols Using Superacidic Polyoxometalate-Based Ionic Hybrids Catalysts

Improving the catalytic efficiency in the hydration of olefins to alcohols is an important yet challenging issue in acid catalysis. Herein, a series of novel superacidic polyoxometalate-based ionic hybrids were prepared and employed as catalysts for highly efficient indirect hydration of olefins to corresponding alcohols. Several characterization techniques such as FT-IR spectra, XRD, SEM, and P-31 MAS NMR spectroscopy were performed to characterize the structures of these superacid hybrids and their acid properties. The results show that the catalytic performances of ionic hybrids were closely related to their acidic strength. The superacidic ionic hybrid [BPy-SO3H-OTf]PW was found to be the best active catalyst to obtain the corresponding alcohols with good yields. The catalytic efficiency in indirect hydration process using superacidic ionic hybrid catalysts is obviously superior to that of direct hydration, which thus opens up a new way to improve the efficiency of the current hydration process.