Advertisement

Topics

Highly Stable Zr(IV)-Based Metal-Organic Frameworks with Chiral Phosphoric Acids for Catalytic Asymmetric Tandem Reactions.

08:00 EDT 15th April 2019 | BioPortfolio

Summary of "Highly Stable Zr(IV)-Based Metal-Organic Frameworks with Chiral Phosphoric Acids for Catalytic Asymmetric Tandem Reactions."

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 with metal ions. A pair of chiral porous Zr(IV)-MOFs with the framework formula [Zr6O4(OH)8(H2O)4(L)2] were prepared from enantiopure 4,4',6,6'-tetra(benzoate) and -tetra(2-naphthoate) ligands of 1,1'-spirobiindane-7,7'-phosphoric acid. They share the same topological structure but differ in channel sizes, and both of them demonstrate excellent tolerance towards water, acid and base. Significantly enhanced Brønsted acidity was observed for the phosphoric acids that are uniformly distributed within the frameworks in comparison with the non-immobilized acids. This not only facilitates the catalysis of asymmetric two-component tandem acetalization, Friedel-Crafts and iso-Pictet-Spengler reactions, but also promotes the catalysis of asymmetric three-component tandem deacetalization-acetalization and Friedel-Crafts reactions benefiting from the synergy with exposed Lewis acidic Zr(IV) sites. The enantioselectivities are comparable or favorable compared to those obtained from the corresponding homogeneous systems. The features of high reactivity, selectivity, stability and recyclability for Zr(IV)-MOFs make them hold promise as a new type of heterogeneous acid catalyst for the eco-friendly synthesis of fine chemicals.

Affiliation

Journal Details

This article was published in the following journal.

Name: Journal of the American Chemical Society
ISSN: 1520-5126
Pages:

Links

DeepDyve research library

PubMed Articles [27293 Associated PubMed Articles listed on BioPortfolio]

3D enantiomorphic Mg(II)-based metal-organic frameworks as chemical sensor of nitrobenzene and efficient catalyst for the CO2 cycloaddition.

Two enantiomorphic Mg(II)-based metal-organic frameworks, {MgL(H2O)2}n (1-D and 1-L) (where, H2L = 2,2'-bipyridyl-4,4'-dicarboxylic acid) have been synthesized by solvothermal reaction without any chi...

Transformation of Metal-Organic Frameworks into Stable Organic Frameworks with Inherited Skeletons and Catalytic Properties.

Metal-organic frameworks (MOFs) are an emerging class of porous materials with attractive properties; however, their practical applications are heavily hindered by the fragile nature. We report herein...

Exceptional adsorption of arsenic by zirconium metal-organic frameworks: Engineering exploration and mechanism insight.

Highly stable zirconium metal-organic frameworks (UiO-66 and UiO-66(NH)) had been synthesized and investigated to remove arsenic (As) from contaminated water. The As(III, V) removal performance was st...

Reticular Access to Highly Porous acs-MOFs with Rigid Trigonal Prismatic Linkers for Water Sorption.

Metal-organic frameworks (MOFs) based on edge-transitive 6-c acs nets are well-developed and can be synthesized from trinuclear metal clusters and ditopic ligands, i.e., MOF-235 and MIL-88. The ration...

Solvent-Free, Single Lithium-Ion Conducting Covalent Organic Frameworks.

Porous crystalline materials such as covalent organic frameworks and metal-organic frameworks have garnered considerable attention as a promising ion conducting medium. However, most of them additiona...

Clinical Trials [6166 Associated Clinical Trials listed on BioPortfolio]

One Year Clinical Evaluation of Milled BioHPP Polyetheretherketone (PEEK)-Based Versus Metal Ceramic Single Crowns

Although the metal-ceramic system is still widely used to fabricate crowns and fixed partial dentures and is considered as the standard treatment in dentistry, aesthetic concerns have stim...

Metal Ion Release From an FDA-Approved Metal-on-Metal Total Hip Replacement Implant

This is a multi-center, randomized study to compare blood and urine cobalt, chromium, and titanium ion levels of a metal-on-metal articular bearing coupled with two different head sizes to...

A Multicentre Trial to Compare Two Articulating Bearing Surfaces as Used in Cementless Primary Hip Arthroplasty

The aim of this study is to demonstrate the non-inferiority of the ceramic-on-metal articulation using large diameter bearings (38mm to 60mm) compared to the metal on metal articulation us...

A Clinical Evaluation of Metal Ion Release From Metal-on-Metal Cementless Total Hip Arthroplasty

A clinical Evaluation to determine metal ion release from 4th generation metal-on-metal hip articulating surfaces in cementless total hip arthroplasty.

Investigation of Systemic Metal Ion Concentration Following a Ceramic-on-Metal Total Hip Arthroplasty

This is a pilot study to compare systemic concentrations of cobalt and chromium in patients that have previously undergone total hip arthroplasties with ceramic on metal and metal on metal...

Medical and Biotech [MESH] Definitions

Supramolecular networks that consist of ordered arrangements of organic electron donor linkers (usually ditopic or polytopic organic carboxylates) and metal cations. They can have an extremely high surface area and adjustable pore size that allows for the insertion of other molecules capable of various functions such as catalysis, capture of carbon dioxide, and drug delivery.

Polymers of N-SUBSTITUTED GLYCINES containing chiral centers at the a-position of their side chains. These oligomers lack HYDROGEN BONDING donors, preventing formation of the usual intrachain hydrogen bonds but can form helices driven by the steric influence of chiral side chains.

Organic polymeric materials which can be broken down by naturally occurring processes. This includes plastics created from bio-based or petrochemical-based materials.

The fusion of ceramics (porcelain) to an alloy of two or more metals for use in restorative and prosthodontic dentistry. Examples of metal alloys employed include cobalt-chromium, gold-palladium, gold-platinum-palladium, and nickel-based alloys.

A cell adhesion protein that was originally identified as a heat stable antigen in mice. It is involved in METASTASIS and is highly expressed in many NEOPLASMS.

Advertisement
Quick Search
Advertisement
Advertisement

 


DeepDyve research library

Searches Linking to this Article