Palladium catalyst coordinated in knitting N-heterocyclic carbene porous polymers for efficient Suzuki–Miyaura coupling reactions

2015 ◽  
Vol 3 (3) ◽  
pp. 1272-1278 ◽  
Author(s):  
Shujun Xu ◽  
Kunpeng Song ◽  
Tao Li ◽  
Bien Tan

Microporous polymers were synthesised using external cross-linked N-heterocyclic carbene and benzene. These materials can serve as ligands to bind metal ions and demonstrated high catalytic activity for efficient Suzuki–Miyaura coupling reactions.

2020 ◽  
Vol 11 (1) ◽  
pp. 7632-7645

Work is focused on OHCP-PdNPs synthesis with the help of meso-modified OHCP derivatives. OHCP-PdNPs utilized for the C-C coupling reactions as an efficient nanocatalyst. This study includes the stability as well as pH studies of fine PdNps. OHCP is an electron-rich ligand that is capable of reducing as well as encapsulate the metal ions because of the availability of electron-rich hydrazide functional group and H-bonding promoter four pyrrole units. In comparison with normal hydrazine, CP-hydrazide has a higher withdrawal ability, so Pd-NPs periphery is surrounded by them and undergoes stronger web-like capping on palladium. Similarly, OHCP-PdNPs are aqueous and air-stable, besides affordable alternatives for the synthesis of stable PdNPs. Moreover, encapsulating the periphery of PdNPs using OHCP enhances its activity and selectivity. Which indicates the perfect association of metal-cage recognition? This recognition may lead to numerous promising applications towards an efficient catalytic activity.


2019 ◽  
Vol 7 (21) ◽  
pp. 13142-13148 ◽  
Author(s):  
Liang-Liang Yang ◽  
Hong-Juan Wang ◽  
Juan Wang ◽  
Yu Li ◽  
Wen Zhang ◽  
...  

A new graphdiyne-based carbon material was synthesized as an ideal substrate for electroless deposition and stabilization of sub-nanometric Pd catalysts, which showed extremely high catalytic activities for the reduction of nitroarenes and Suzuki coupling reactions.


RSC Advances ◽  
2014 ◽  
Vol 4 (69) ◽  
pp. 36437-36443 ◽  
Author(s):  
Zhenhong Guan ◽  
Buyi Li ◽  
Guoliang Hai ◽  
Xinjia Yang ◽  
Tao Li ◽  
...  

Microporous polymers with built-in triphenylphosphine palladium exhibit highly efficient catalytic activity for cross-coupling reactions of benzyl chloride under mild conditions.


2014 ◽  
Vol 70 (9) ◽  
pp. 1548-1554 ◽  
Author(s):  
Deli Wu ◽  
Yanxia Liu ◽  
Dong Duan ◽  
Luming Ma

Pyrite cinder (PyC) was employed as a heterogeneous Fenton-like catalyst, and its catalytic activity was evaluated in view of the effects of catalyst dosage, pH and leaching metal ions. PyC showed significant reactivity, and the pseudo-first-order kinetic rate constant for decomposition of H2O2 and degradation of Acid Red B (ARB) were 3.4 and 14.89 (10−3 min−1) respectively when pH = 5. When 20 g/L PyC was added into 10 mM H2O2 solution in neutral pH, H2O2 could be completely degraded within 4 h, and more than 90% ARB was removed. Leaching metal ions from PyC were found to have little effect on decomposition of H2O2 or on degradation of ARB. PyC still had high catalytic activity after five successive runs. The decomposition mechanism of H2O2 was analyzed and the Haber–Weiss mechanism was employed in this paper. The electron spin resonance image showed •OH was produced and increased between 3 and 5 min in the PyC catalyzing H2O2 reaction, which demonstrated that PyC had a durable ability to produce •OH.


Synlett ◽  
2018 ◽  
Vol 29 (06) ◽  
pp. 717-722 ◽  
Author(s):  
Teruyuki Kondo ◽  
Ryosuke Taniguchi ◽  
Yu Kimura

Ru3(CO)12-catalyzed divergent ring-opening coupling reactions of a cyclopropenone with methyl acrylate (an electron-deficient alkene) are developed. Under an argon atmosphere, a decarbonylative linear codimer is obtained, while cyclopentenones are obtained under carbon monoxide (20 atm) without decarbonylation. While ruthenium complexes show no catalytic activity for the ring-opening cocyclization of cyclopropenones with ethylene (20 atm) or bicyclo[2.2.1]hept-2-ene (2-norbornene), rhodium complexes, especially [RhCl(η4-1,5-cod)]2, show high catalytic activity for the desired cocyclization reactions to give the corresponding cyclopentenones in high yields and selectivities. In addition, [RhCl(η4-1,5-cod)]2 realizes the catalytic ring-opening co­cyclization of cyclopropenones with internal alkynes to give the corresponding cyclopentadienones. In all these reactions, ruthena- or rhodacyclobutenones are considered to be key intermediates, generated by strain-driven oxidative addition of a cyclopropenone C–C bond to an ­active ruthenium or rhodium species.


Synthesis ◽  
2017 ◽  
Vol 49 (18) ◽  
pp. 4372-4382 ◽  
Author(s):  
Mohammed Waheed ◽  
Naseem Ahmed

2-Hydroxyindan-1-ones have been efficiently synthesized and successfully applied as ligands in Pd-catalyzed Ullmann type, Suzuki–Miyaura, and Mizoroki–Heck cross-coupling reactions with aryl tosylates and aryl halides. The ligands are air- and moisture-stable and have shown high catalytic activity with Pd(OAc)2 in these cross-coupling reactions. The system tolerates a variety of functional groups in the product and can be re-used at least three times with maximum efficiency.


2015 ◽  
Vol 5 (6) ◽  
pp. 3194-3202 ◽  
Author(s):  
Nan Mei ◽  
Bing Liu ◽  
Judun Zheng ◽  
Kangle Lv ◽  
Dingguo Tang ◽  
...  

Magnetically separable, graphene oxide-supported palladium nanoparticles showed high catalytic activity for the aerobic oxidation of 5-hydroxymethylfurfural into 2,5-furandicarboxylic acid.


2021 ◽  
Vol 11 (11) ◽  
pp. 4822
Author(s):  
Hamed M. Alshammari ◽  
Obaid F. Aldosari ◽  
Mohammad Hayal Alotaibi ◽  
Raja L. Alotaibi ◽  
Mosaed S. Alhumaimess ◽  
...  

Palladium-based carbon catalysts (Pd/C) can be potentially applied as an efficient catalyst for Suzuki–Miyaura and Mizoroki–Heck coupling reactions. Herein, a variety of catalysts of palladium on activated carbon were prepared by varying the content of ‘Pd’ via an in situ reduction method, using hydrogen as a reducing agent. The as-prepared catalysts (0.5 wt % Pd/C, 1 wt % Pd/C, 2 wt % Pd/C and 3 wt % Pd/C) were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Brunauer–Emmett–Teller (BET) analyses. The catalysts were tested as a coupling catalyst for Suzuki–Miyaura coupling reactions involving aryl halides and phenyl boronic acid. The optimization of the catalyst by varying the palladium content on the activated carbon yielded Pd/C catalysts with very high catalytic activity for Suzuki reactions of aryl halides and a Mizoroki–Heck cross-coupling reaction of 4-bromoanisol and acrylic acid in an aqueous medium. A high ‘Pd’ content and uniform ‘Pd’ impregnation significantly affected the activity of the catalysts. The catalytic activity of 3% Pd/C was found to make it a more efficient catalyst when compared with the other synthesized Pd/C catalysts. Furthermore, the catalyst reusability was also tested for Suzuki reactions by repeatedly performing the same reaction using the recovered catalyst. The 3% Pd/C catalyst displayed better reusability even after several reactions.


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