Heterogeneous Asymmetric Catalysis with Homochiral Metal-Organic Frameworks: Network-Structure-Dependent Catalytic Activity

摘要

The prospect of generating functional solids by rational design has spurred a recent explosive growth of interest in research into metal-organic frameworks (MOFs).[1], [2] A particular focus in this research area has been placed upon porous MOFs because of their intrinsic zeolite-mimicking, size- and shape-selective properties which make them potentially useful in a number of applications such as catalysis,[3] gas storage,[4] separation,[5] and ion-exchange processes.[6] By taking advantage of the mild conditions that are typically used for the synthesis of MOFs, we and others have successfully synthesized catalytically active homochiral porous MOFs by incorporating chiral constituent building blocks that contained orthogonal functionalities.[7] The single-crystalline nature of MOFs allows detailed structural interrogation, which makes it possible to examine the relationship between the structure and the catalytic activity of homochiral porous MOFs in great detail. A detailed understanding of the structure-activity relationship is key to further fine-tuning the catalytic performance of MOFs by judicious choice of building blocks. Herein we report two homochiral porous MOFs built from the same chiral bridging ligand and metal connecting point. Their drastically different catalytic activities are readily rationalized on the basis of their different framework structures.