Development of a novel Brønsted acid UiO-66 metal–organic framework catalyst by postsynthetic modification and its application in catalysis
Abstract
A novel Brønsted acid derived metal–organic framework (MOF) has been developed to serve as an efficient heterogeneous catalyst for the acetalization and Morita–Baylis–Hillman reaction. Aromatic sulfonic acid groups were successfully incorporated to the framework of UiO-66 by post-synthetic modifications using commercially available anhydridic reagents. The UiO-66-RArSO3H Brønsted acid catalyst was fully characterized using SEM, PXRD, FTIR, TGA and N2 adsorption/desorption isotherms. Furthermore, efficient acetalization and Morita–Baylis–Hillman reactions were evaluated to demonstrate the high catalytic performance of the UiO-66-RArSO3H catalyst. The UiO-66-RArSO3H catalyst is compatible with a variety of substituted substrates and can be recycled five times without a compromise in the yield or selectivity.