Highly Stable Zr(IV)-Based Metal–Organic Frameworks with Chiral Phosphoric Acids for Catalytic Asymmetric Tandem Reactions
作者:Wei Gong、Xu Chen、Hong Jiang、Dandan Chu、Yong Cui、Yan Liu
DOI:10.1021/jacs.9b02294
日期:2019.5.8
Heterogeneous Brønsted acid catalysts featuring high porosity, crystallinity, and stability have been of great interest for both fundamental studies and practical applications, but synthetically, they still face a formidable challenge. Here, we illustrated a ligand design strategy for directly installing chiral phosphoric acid catalysts into highly stable Zr-MOFs by sterically protecting them from coordinating
具有高孔隙率、结晶度和稳定性的多相 Brønsted 酸催化剂在基础研究和实际应用中都引起了极大的兴趣,但综合起来,它们仍然面临着巨大的挑战。在这里,我们展示了一种配体设计策略,通过在空间上保护它们免于与金属离子配位,将手性磷酸催化剂直接安装到高度稳定的 Zr-MOF 中。从对映体纯的 4,4',6,6'-四(苯甲酸酯)和 - 制备了一对骨架式为 [Zr6O4(OH)8(H2O)4(L)2] 的手性多孔 Zr(IV)-MOFs 1,1'-spirobiindane-7,7'-磷酸的四(2-萘甲酸)配体。它们具有相同的拓扑结构,但通道大小不同,并且都表现出对水、酸和碱的优异耐受性。与非固定酸相比,均匀分布在骨架内的磷酸的布朗斯台德酸度显着增强。这不仅促进了不对称双组分串联缩醛化、Friedel-Crafts 和iso-Pictet-Spengler 反应的催化,而且促进了不对称三组分串联脱缩醛化-缩醛化和