Au NPs fabricated on biguanidine-modified Zr-UiO-66 MOFs: a competent reusable heterogeneous nanocatalyst in the green synthesis of propargylamines

In this study, we utilized functionalized metal organic frameworks (MOFs) as a host matrix to embed gold (Au) nanoparticles. The three-dimensional Zr-based metal-organic framework UiO-66-NH2 was functionalized with the biguanidine moiety using a post-synthetic modification (PSM) strategy, and then gold salt was successfully immobilized onto the surface of the biguanidine-functionalized Zr-MOF. The morphological and physicochemical features of the material were determined using several advanced techniques like FT-IR spectroscopy, SEM, TEM, EDX spectroscopy, elemental mapping, XRD and ICP-OES. The SEM, BET and XRD results showed that the morphology and structure of the Zr-MOF were retained after multiple transformations. The obtained UiO-66-bigua/Au nanocomposite exhibited excellent activity in the three-component reaction of aldehydes, amines and alkynes (A(3) coupling) with good to high yields of diverse propargylamines. Furthermore, the catalyst could be recovered and reused 8 times with no significant reduction in its activity.

Automated summary

In this study, functionalized metal organic frameworks were used as a host matrix to embed gold nanoparticles. The material was characterized using advanced techniques, and it was found that the morphology and structure of the material remained stable after multiple transformations. The obtained nanocomposite showed excellent catalytic activity in multi-component reactions and could be reused multiple times.