Cooperative Multifunctional Catalysts for Nitrone Synthesis: Platinum Nanoclusters in Amine‐Functionalized Metal–Organic Frameworks

Abstract

Nitrones are key intermediates in organic synthesis and the pharmaceutical industry. The heterogeneous synthesis of nitrones with multifunctional catalysts is extremely attractive but rarely explored. Herein, we report ultrasmall platinum nanoclusters (PtNCs) encapsulated in amine-functionalized Zr metal-organic framework (MOF), UiO-66-NH (Pt@UiO-66-NH ) as a multifunctional catalyst in the one-pot tandem synthesis of nitrones. By virtue of the cooperative interplay among the selective hydrogenation activity provided by the ultrasmall PtNCs and Lewis acidity/basicity/nanoconfinement endowed by UiO-66-NH , Pt@UiO-66-NH exhibits remarkable activity and selectivity, in comparison to Pt/carbon, Pt@UiO-66, and Pd@UiO-66-NH . Pt@UiO-66-NH also outperforms Pt nanoparticles supported on the external surface of the same MOF (Pt/UiO-66-NH ). To our knowledge, this work demonstrates the first examples of one-pot synthesis of nitrones using recyclable multifunctional heterogeneous catalysts.

Engineering UiO‐66 Metal Organic Framework for Heterogeneous Catalysis

“…[86] The observed catalytic activity was due to the cooperative interplay among the selective [86] The observed catalytic activity was due to the cooperative interplay among the selective …”

Recent Advances of MOFs and MOF‐Derived Materials in Thermally Driven Organic Transformations

“…The resulting composite exhibits excellent catalytic activity and selectivity for acetal products in a one‐pot cascade oxidation‐acetalization reaction . Following this work, they continued to report the synthesis of an analogous Pt@UiO‐66‐NH 2 composite, which is the first example of a one‐pot synthesis of nitrones, key intermediates often used in the pharmaceutical industry (Figure ) . The small MOF cavities led to the formation of ultra‐small Pt nanoclusters (≈1.1 nm).…”

“…(B) Typical TEM image of Pt@UiO‐66‐NH 2 with a 2 wt % Pt loading. (C) The nitrone synthesis is carried out in a two‐step reaction including the hydrogenation of nitromethane and then the condensation of benzaldehyde (the reaction is highlighted in the solid rectangle) and possible side reactions …”

Metal‐Organic Frameworks Based on Multicenter‐Bonded [MI]8 (M=Mn, Zn) Clusters with Cubic Aromaticity

“…Metal‐organic frameworks (MOFs) are promising candidates for utilization in adsorption/separation, catalysis, chemical sensing and proton conductivity, which are built up from organic ligands and metal ions or clusters. Metal ions usually play an essential role in constructing functional MOFs.…”