Highly Stable Copper(I)-Based Metal–Organic Framework Assembled with Resorcin[4]arene and Polyoxometalate for Efficient Heterogeneous Catalysis of Azide–Alkyne “Click” Reaction

Abstract

A new highly stable copper(I)-based metal-organic framework (MOF), namely, [Cu(SiWO)(L)]·6HO·2DMF (1), was synthesized by incorporating Keggin-type polyoxometalate (POM) anions and a functionalized wheel-like resorcin[4]arene-based ligand (L) under sovothermal condition. 1 exhibits a charming 3D supramolecular architecture sandwiched by the POM anions. Noticeably, 1 has exceptional chemical stability, especially in organic solvents or aqueous solutions with a wide range of pH values. Considering the catalytically active Cu(I) sites in 1, the azide-alkyne cycloaddition (AAC) reaction was studied by employing 1 as the heterogeneous catalyst. Most strikingly, 1 exhibits excellent catalytic activity as well as recyclability for the AAC reaction.

Highly Stable Copper(I)–Thiacalix[4]arene‐Based Frameworks for Highly Efficient Catalysis of Click Reactions in Water

“…For example, if phenylacetylene reacts with benzyl azide derivatives, the yield can reach 99 %. If the catalytic reactions of benzyl azide with various phenylacetylene derivatives were performed, slightly lower conversions of about 92 and 89 % (Table , entries 7 and 8) were achieved for Cl‐ and Br‐substituted phenylacetylenes, respectively; this may arise due to the steric hindrance effect of the substituted groups …”

“…Notably, catalyst 1‐Cl features efficient catalytic performances for the AAC reactions under relatively mild reaction conditions. For example, the product yield is up to 99 % for the AAC reaction of benzyl azide and phenylacetylene with catalyst 1‐Cl at 60 °C for 8 h. Nevertheless, for related catalysts [Cu 4 (SiW 12 O 40 )(L1)] ⋅ 6 H 2 O ⋅ 2 DMF (L1=resorcin[4]arene‐based ligand) and [Cu 4 (SiW 12 O 40 )(L2) 2 (DMF) 2 ] ⋅ 2 EtOH ⋅ DMF (L2=thiacalix[4]arene‐based ligand), the same AAC reaction was accomplished (99 %) if the reaction temperature was elevated to 80 °C and the reaction time was prolonged to 12 h. In addition, catalyst 1‐Cl features a remarkable recyclability for the AAC reaction. For instance, a product yield of 97 % was still retained in the fifth run, whereas the corresponding yield for the catalyst {[Cu 6 (bpz) 6 (CH 3 CN) 3 (CN) 3 Br] ⋅ 2 OH ⋅ 14 CH 3 CN} n (bpz=3,3′,5,5′‐tetramethyl‐4,4′‐bipyrazole) was only up to 68 % .…”

“…In this regard, heterogeneous Cu I ‐based MOF catalysts for click reactions exhibit some advantages, such as improved stability, easy separation, and high reusability . Nevertheless, the reported works directly using Cu I MOFs as heterogeneous catalysts for click′ reactions are usually conducted in organic or mixed solvents (such as ethanol and water) . By contrast, water, as a cheap, nontoxic, safe, and green solvent, has received far less attention in CuAAC reactions with Cu I MOFs as heterogeneous catalysts …”

Synthesis of 1,2,3‐Triazole Tethered 3‐Hydroxy‐2‐oxindoles: Promising Corrosion Inhibitors for Steel in Acidic Medium and Their Anti‐Microbial Evaluation

“…Further, the requirement of reducing agents and stabilizing ligands are considered potential disadvantages of this method. In this regard, the heterogeneous catalytic system is finding remarkable attention due to its merits such as catalyst recovery by simple filtration, reusability of catalyst, and additives are not required . Even though CuAAC reactions are proficiently performed in conventional solution phase, there is an increasing demand for non‐conventional approaches such as mechanochemistry (ball milling), microwave and ultrasound irradiation in terms of economical (feedstock) and environmental (energy consumption) response .…”

Three resorcin[4]arene-based lanthanide-coordination polymers with multifunctional photoluminescence sensing properties

“…22,23 Thus far some metal-organic frameworks with fascinating structures and properties have been synthesized by applying the resorcin [4]arene-based ligands. 24,25 Remarkably, carboxylate-functionalized resorcin [4]arene ligands have been proven to exhibit strong "antennae effects" in building luminescent Ln-CPs. 26,27 Based on above consideration, we herein report three Ln-CPs, namely,…”