Department of Chemistry, Iowa State University, Ames, IA, 50011, USA.
Ames Laboratory, US Department of Energy, Ames, IA, 50011, USA.
Angew Chem Int Ed Engl. 2017 Dec 18;56(51):16371-16375. doi: 10.1002/anie.201710164. Epub 2017 Nov 22.
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.
氮氧自由基是有机合成和制药工业中的关键中间体。用多功能催化剂进行氮氧自由基的多相合成极具吸引力，但很少有人探索。在此，我们报告了在胺功能化的 Zr 金属有机骨架（UiO-66-NH）中封装的超小铂纳米团簇（PtNCs）（Pt@UiO-66-NH）作为一锅串联合成氮氧自由基的多功能催化剂。由于超小 PtNCs 提供的选择性加氢活性与 UiO-66-NH 赋予的路易斯酸度/碱度/纳米限域之间的协同作用，Pt@UiO-66-NH 表现出显著的活性和选择性，与 Pt/碳、Pt@UiO-66 和 Pd@UiO-66-NH 相比。Pt@UiO-66-NH 也优于相同 MOF 外表面负载的 Pt 纳米颗粒（Pt/UiO-66-NH）。据我们所知，这项工作展示了使用可回收多功能多相催化剂一锅法合成氮氧自由基的首例实例。
