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A new metal–organic polyhedron with a high surface area of 407 m2 g−1, possessing high CO2 uptake, is reported, which is synthesized using 4-connected Cu2(CO2)4 paddle-wheel moieties and 3-connected semi-rigid tripodal carboxylates. This material possesses a high density of Cu(II) Lewis acidic sites and demonstrates excellent performance as a heterogeneous catalyst for the chemical fixation of CO2 into cyclic carbonates under ambient conditions. [ABSTRACT FROM AUTHOR]

A cationic covalent organic polymer with bifunctional active site was synthesized, which was treated by N, N'-bis(5-bromomethylsalicylaldehyde)ethylenediamine (salen ligand) and tris(1H-imidazol-1-yl) triazine (TIT) in the presence of aluminum ethoxide. The bifunctional cationic covalent organic polymer was investigated by various characterization technologies including PXRD, FT-IR, XPS, TG, SEM, EDS, N2-adsorption and CO2-adsorption. In this polymer, aluminum acts as lewis acid site and bromine ion acts as nucleophile, cooperatively catalyzing the cycloaddition reaction of CO2 and epoxides. Due to its cooperative effect, a higher catalytic activity was found to exhibit 98.1% conversion of epichlorohydrin under optimized conditions (Initial pressure 1.0 MPa, 0.57 mol% catalyst of COP-Al, 90 °C, reaction time 18 h, in the absence of a co-catalyst). Notably, the heterogeneous catalyst still showed good activity and stability after five cycles. A salen-based cationic covalent organic polymers (COP-Al) was used as a bifunctional catalyst for the cycloaddition reaction of CO2 and epoxides with high activity under solvent-free and co-catalyst-free conditions. [ABSTRACT FROM AUTHOR]

Brönsted acid and metal nanoparticles are important catalytic functional groups. In this work, a bifunctional heterogeneous catalyst with both strong Brönsted acid and metal nanoparticles was prepared. First Brönsted acid groups were obtained by sulfonating graphene oxide, next metal organic frameworks MIL‐101 (Cr) grew on sulfonated graphene oxide (SGO), then palladium nanoparticles (NPs) were encapsulated in MIL‐101@SGO composites. The catalyst was characterized by a variety of different techniques including XRD, SEM, TEM, EDS, FT‐IR, TGA, and nitrogen physisorption measurements. Tandem heterogeneous catalysis of Pd@MIL‐101@SGO was investigated for the one‐pot direct conversion of styrene into β‐alkoxy alcohol. The catalyst retained high catalytic activity after 5 times of reuses in aqueous solutions. No loss of crystal structure was detected by PXRD and no leakage of Pd was detected by ICP‐AES. Therefore, Pd@MIL‐101@SGO proved to be an effective recyclable heterogeneous catalyst for synthesizing β‐alkoxy alcohol and exhibited potential application in industry. [ABSTRACT FROM AUTHOR]

Two series of chemically and thermally stable rare-earth MOFs were constructed using trinuclear [M3(μ3-OH)(COO)6] SBUs and linear dicarboxylate linkers, which feature three-dimensional 12-connected frameworks with an hcp topology. These materials contain a large density of Lewis acidic sites, leading to high catalytic activity towards the cycloaddition of CO2 and epoxides under mild conditions. [ABSTRACT FROM AUTHOR]

By ultrasonic technique, a stable benzimidazole-containing Co(II) coordination polymer namely [Co(L) 0.5 (oba)] n (1) was successfully synthesized under mild conditions. As a heterogeneous Lewis catalyst, 1 exhibit a highly activity and recyclability for CO 2 transformation by cycloaddition with epoxide under room temperature. • Synthesis of a stable benzimidazole-containing Co(II) coordination polymer 1 using ultrasonic method at room temperature. • The concentrations of initial reagents, ultrasonic power and time could influence the morphology and size of 1. • 1 exceptional solvent and pH stabilities. • 1 applied as efficient Lewis acid catalysts for carbon dioxide cycloaddition. A stable benzimidazole-containing Co(II) coordination polymer namely [Co(L) 0.5 (oba)]n (1) (H 2 oba = 4,4′-oxybis(benzoate), L = 1,6-bis(5,6-dimethylbenzimidazolyl) hexane) was successfully synthesized by ultrasonic technique under mild conditions. In especial, the effects of initial reagent concentration, irradiation time and ultrasonic power on the morphology and size of micron scale 1 were discussed in detail. Micron scale 1 appeared exceptional solvent and pH stabilities. Further, as a heterogeneous Lewis catalyst, 1 exhibited a highly activity and recyclability for CO 2 transformation by cycloaddition with epoxide under room temperature. [ABSTRACT FROM AUTHOR]

Abstract Bifunctional Cr-MOF catalysts containing palladium nanoparticles (NPs) have been prepared. Combining the high activity of Pd NPs and base sites in MIL-101-NH 2 , the catalysts (Pd@MIL-101-NH 2) exhibited distinct catalytic activity in a one-pot Suzuki-Knoevenagel reaction. Pd@MIL-101-NH 2 has been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and fourier transform infrared spectroscopy (FT-IR). Various substituted phenylboronic acids were used to research the one-pot reaction. The results were highly satisfactory, not only got high yield, but reduced reaction time. Leakage experiments further demonstrated that there is no leaching of active palladium nanoparticles during the reactions. Catalysts could be reused for at least five cycles and activity is not significantly decreased. Graphical abstract In this paper, Pd@MIL-101-NH 2 were synthesized, which was used as heterogeneous catalysts for one-pot Suzuki-Knoevenagel reactions. As expected that Pd@MIL-101-NH 2 exhibited remarkably catalytic activity and selectivity. Moreover, other reaction conditions have also been explored involving solvents, reaction temperatures and other catalysts for the sake of achieving the best catalytic efficiency. Unlabelled Image Highlights • Pd@MIL-101-NH 2 composite was synthesized by a facile method. • Pd@MIL-101-NH 2 composite is Bifunctional catalyst • Pd@MIL-101-NH 2 composite may be an effective catalyst for one-pot Suzuki-Knoevenagel reactions in industry [ABSTRACT FROM AUTHOR]

Heterogeneous homocoupling reactions of phenylboronic acids were greatly accelerated via Suzuki homocoupling reactions. In this work, a tandem route was designed which firstly one part of phenylboronic acids reacted with iodine to form iodobenzenes, then another part of phenylboronic acids coupled with iodobenzenes to produce biaryl compounds. The tandem reaction were catalyzed by a bifunctional heterogeneous catalyst of metal organic frameworks encapsulated with palladium nanoparticles (Pd@MOFs). • A catalyst catalyzes a tandem reaction. • Pd@HKUST-1 composite synthesized by facile method is a bifunctional heterogeneous catalyst. • Pd@HKUST-1 composite can be reused. Heterogeneous homocoupling reactions of phenylboronic acids were greatly accelerated via Suzuki homocoupling reactions. In this work, a tandem route was designed which firstly one part of phenylboronic acids reacted with iodine to form iodobenzenes, then another part of phenylboronic acids coupled with iodobenzenes to produce biaryl compounds. The tandem reaction were catalyzed by a bifunctional heterogeneous catalyst of metal organic frameworks encapsulated with palladium nanoparticles (Pd@MOFs). This strategy for forming symmetric C-C bond between benzene rings has obvious advantages such as high efficiency, easy separation, good recyclability and no addition of toxic halogenated benzene. [ABSTRACT FROM AUTHOR]

A hexanuclear Y(III) clusters-based MOFs was successfully synthesized, then the functional Pd(bpydc)Cl 2 species were quantitatively incorporated into this material via sequential post-synthetic ligand exchange and metalation. The obtained Pd(II)-Y- bpydc X /bpdc 1-X MOFs can be as highly efficient heterogeneous single-site catalysts to promote selective oxidative cleavage of styrene to benzaldehyde using O 2 as a green oxidant. • A novel hexanuclear Y(III) clusters-based MOFs was successfully synthesized. • The functional Pd(bpydc)Cl2 species were quantitatively incorporated into this MOF. • The strategy of post-synthetic ligand exchange and metalation was employed. • The Pd(bpydc)Cl2-Y6-MOFs can be as efficient heterogeneous single-site catalysts. • The catalysts can promote selective oxidative cleavage of styrene to benzaldehyde. Oxidation of styrene is one of the significant reactions in organic synthesis. In this work, a serious of PdCl 2 moiety-decorated Y 6 -MOFs adopting post-synthetic strategy were fabricated as applicable single-site catalysts for oxidation of styrene. Specifically, the functional organic linker, H 2 bpydc (2,2′-bipyridine-5,5′-dicarboxylic acid), was first incorporated quantitatively into Y 6 clusters-based MOF, [(CH 3) 2 NH 2 2 [Y 6 (μ 3 -OH) 8 (bpdc) 6 (bpdc = 4,4′-biphenyl dicarboxylic acid) via post-synthetic ligand exchange. Then post-synthetic Pd(II) metalation was performed to enhance the density of isolated single sites. The obtained Pd(II)-Y-bpydc x /bpdc 1-x can be used as highly efficient heterogeneous single-site catalysts to promote selective oxidative cleavage of styrene to benzaldehyde using O 2 as a oxidant under solvent-free and mild reaction conditions (1 atm and 80 °C). Importantly, when using Pd(II)-Y-bpydc 0.8 /bpdc 0.2 (0.024 mmol Pd) as catalyst, the high conversion of styrene and the selectivity for benzaldehyde can reach 88.7 % and 82.2 %, respectively. [ABSTRACT FROM AUTHOR]