Influence of Hydrogen Bond Donating Sites in UiO-66 Metal-Organic Framework for Highly Regioselective Methanolysis of Epoxides

摘要

A Zr(IV)-based UiO-66 metal-organic framework (MOF) (named 1) was synthesized by employing 1-(aminomethyl)naphthalene-2-ol appended terephthalate linker and Zr(IV) salt via solvothermal method and subsequently characterized. Furthermore, the potential efficiency of activated (named 1 ') form of as-synthesized MOF was investigated as an organocatalyst for the ring-opening of epoxide by methanol. The catalytic performance of 1 and 1 ' was studied in the methanolysis of styrene oxide as a model substrate and the activity of 1 ' was also examined with various alcohols. Under the optimized reaction conditions, the catalytic performance of 1 ' reached 96 % conversion of styrene oxide to its corresponding product with 98 % regioselectivity. The reusability and stability of the catalyst were proved by recycling up to four runs in the methanolysis of styrene oxide. The Lewis acidity originating from metal nodes and hydrogen bond donating (HBD) sites in the linker is distributed homogeneously throughout the framework, thus playing crucial role in the activation of epoxide with easy accessibility.