Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University , Zheda Road 38, Hangzhou 310027, China.
ACS Appl Mater Interfaces. 2017 Mar 22;9(11):9772-9777. doi: 10.1021/acsami.7b00562. Epub 2017 Mar 13.
Mimicking a biocatalytic system has been one of the prevalent strategies for the design of novel and efficient chemical transformations. Among the enzyme-catalyzed reactions, the cooperative interplay of Lewis- and Brønsted-acidic functionalities at active sites represents a common feature in activating reactants. Employing MIL-101(Cr) as a biomimetic platform, we customize a sulfonic group (SOH) into its hierarchical pores to generate a heterogeneous catalyst for transfer hydrogenation of imines by using Hantzsch ester as the reductant. Both aldimines and ketimines were efficiently converted to their hydrogenated counterparts in a manner similar to metal enzymes. The Cr node and sulfonic acid functionality encapsulated in MOF cages worked cooperatively in promoting this transformation, resulting in an enhanced reactivity as compared to its homogeneous analogue. Furthermore, MIL-101(Cr)-SOH could be recycled for many times without considerable loss in reactivity.
模拟生物催化体系一直是设计新型高效化学反应的流行策略之一。在酶催化反应中，活性位点上的路易斯酸和布朗斯台德酸功能的协同作用是激活反应物的共同特征。我们采用 MIL-101(Cr) 作为仿生平台，将磺酸基 (SOH) 引入其分级孔中，生成一种非均相催化剂，用于使用 Hantzsch 酯作为还原剂对亚胺进行转移氢化。醛亚胺和酮亚胺都以类似于金属酶的方式被高效转化为其氢化产物。Cr 节点和磺酸功能团在 MOF 笼中协同作用，促进了这种转化，与均相类似物相比，反应活性得到了增强。此外，MIL-101(Cr)-SOH 可以多次回收，而反应活性没有明显损失。
