Friedel-Crafts alkylation reaction efficiently catalyzed by a di-amide functionalized Zr(IV) metal-organic framework

Abstract

In this work, a di-amide functionalized Zr(IV) metal-organic framework (MOF, 1) was synthesized and characterized with powder XRD, FT-IR, FE-SEM and elemental analysis. Furthermore, thermogravimetric analysis (TGA) of 1 showed thermal stability up to 275 °C. High chemical stability of the MOF was noticed in different organic solvents, under acidic and basic conditions. The BET surface area of this porous framework was 632 m2/g and pore volume was 0.35 cm3/g at p/po = 0.5. Activated MOF material (1′) displayed noticeable catalytic performance in the Friedel-Crafts alkylation between indole (IND) and β-nitrostyrene (NS). The desired product was obtained in quantitative yield using 1′ as a solid catalyst in ethanol at 40 °C. Catalyst stability was proved by leaching and reusability tests. This catalyst also exhibited broad substrate scope for the synthesis of various heterocyclic compounds. Comparison of the present catalytic results with reported data clearly indicates that this solid is able to promote the reaction effectively to attain higher yields by appropriate design of linker with amide functionality.