2020 Volume 63 Issue 2 Pages 96-101
Regioselective hydrogenation of trans-1-phenyl-1,3-butadiene was studied using modified Pd/MOF catalysts in the liquid phase at 65 °C and PH2 5.0 MPa-G. Metal-organic framework compound, MOF–Cr with MIL-101 structure, was prepared with Cr3+ as the corner cation and terephthalic acid as the linker. NO2–MOF–Cr of the same fundamental structure as MOF–Cr was prepared with nitroterephthalic acid as the linker. Core-shell type MOF was prepared using NO2–MOF–Cr as the core MOF and this was covered with shell MOF–Cr. Amino group obtained by reduction of the nitro group of nitroterephthalic acid in the core MOF was essential to accommodate Pd. Pd was supported only on the core MOF by ion-exchange. Of the two aliphatic C=C double bonds of the substrate, the inner C=C double bond was preferentially hydrogenated on Pd catalyst supported on MOF–Cr and core-shell MOF–Cr. However, the end C=C double bond was preferentially hydrogenated on Pd supported on t-butoxycarbonyl (t-Boc) modified core-shell type MOF due to the steric effect.
