Chiral Functionalization of a Zirconium Metal–Organic Framework (DUT-67) as a Heterogeneous Catalyst in Asymmetric Michael Addition Reaction

Abstract

DUT-67, an 8-connected zirconium and 2,5-thiophenedicarboxylate-based metal-organic framework (MOF), was postsynthetically functionalized by l-proline via solvent-assisted linker incorporation to obtain a chiral base catalyst. The parent monocarboxylate could be almost completely exchanged by l-proline after 5 days of treatment. The resulting chiral DUT-67 was demonstrated to be a promising heterogeneous catalyst for the asymmetric Michael addition of cyclohexanone to trans-β-nitrostyrene with excellent yield (up to 96%) and enantioselectivity comparable to that of l-proline in homogeneous reaction (ee of approximately 38%). The Zr-MOF could be reused at least five times without substantial degradation in the crystallinity or catalytic activity. No leaching of catalytically active species into the liquid phase was detected over five cycles.

Engineering Metal–Organic Framework Catalysts for C−C and C−X Coupling Reactions: Advances in Reticular Approaches from 2014–2018

“…Although Ru-MOFs are known, they have not been actively used as direct metathesis catalysts. [175] The MOF was characterized by using PXRD, NMR, SEM, ICP-OES, andB ET.T he crystallinity of the parent framework was preserved upon proline functionalization. [174] DUT-67 ( Figure 48) was functionalized with l-proline to carry out asymmetric Michael addition reactions.…”

“…DUT‐67 (Figure ) was functionalized with l ‐proline to carry out asymmetric Michael addition reactions . The MOF was characterized by using PXRD, NMR, SEM, ICP‐OES, and BET.…”

“… Synthesis of DUT‐67‐pro using solvent‐assisted linker interchange (SALI) (image reproduced with permission from ref. . Copyright 2018, American Chemical Society).…”

A New Synthetic Pathway to Triphenylpyridines via Cascade Reactions Utilizing a New Iron‐Organic Framework as a Recyclable Heterogeneous Catalyst

“…These networks have been considered as highly versatile materials that find applications in many fields . Exclusive properties such as large surface areas, changeable pore size, and structural diversity have introduced MOFs to catalysis community . Albeit a long series of MOFs have been published with detailed data on characterizations, their application in catalysis are yet limited .…”

A new route to triphenylpyridines utilizing ketoximes as building blocks via cascade reactions under iron‐organic framework catalysis

“…The last two decades have witnessed a rapid development of research on metal–organic frameworks (MOFs), a notable class of highly crystalline polymeric materials, self‐assembled from organic linkers with metal ions or metal clusters . Owing to their diverse porous structures with various connectivity and symmetry, MOFs have been extensively explored for applications in numerous fields, ranging from adsorption to biomedical engineering . Highlighted by permanent porosity, adjustable internal surface functionality, and concentrated active sites, MOFs have emerged as promising candidates for catalysis .…”