scholarly journals Bisimino-functionalized dibenzo[a,c]acridines as highly conjugated pincer frameworks for palladium(ii): synthesis, characterization and catalytic performance in Heck coupling

2016 ◽  
Vol 3 (12) ◽  
pp. 1668-1679 ◽  
Author(s):  
Qaiser Mahmood ◽  
Erlin Yue ◽  
Wenjuan Zhang ◽  
Gregory A. Solan ◽  
Tongling Liang ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Pincer Complexes ◽  
Heck Coupling

The NNC-Pd pincer complexes, systematically derived from phenanthrene-9,10-dione, are able to efficiently mediate the coupling of haloarenes with vinyl-containing substrates (up to TON = 174 000) with a broad substrate scope.

scholarly journals Robust and efficient hydrogenation of carbonyl compounds catalysed by mixed donor Mn(I) pincer complexes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wenjun Yang ◽  
Ivan Yu. Chernyshov ◽  
Robin K. A. van Schendel ◽  
Manuela Weber ◽  
Christian Müller ◽  
...  
Keyword(s):  
Noble Metal ◽  
Crucial Role ◽  
Carbonyl Compounds ◽  
Catalytic Performance ◽  
Hydrogen Atmosphere ◽  
Pincer Complexes ◽  
Catalyst Activation ◽  
Hydrogenation Catalysts ◽  
Induction Times

AbstractAny catalyst should be efficient and stable to be implemented in practice. This requirement is particularly valid for manganese hydrogenation catalysts. While representing a more sustainable alternative to conventional noble metal-based systems, manganese hydrogenation catalysts are prone to degrade under catalytic conditions once operation temperatures are high. Herein, we report a highly efficient Mn(I)-CNP pre-catalyst which gives rise to the excellent productivity (TOF° up to 41 000 h−1) and stability (TON up to 200 000) in hydrogenation catalysis. This system enables near-quantitative hydrogenation of ketones, imines, aldehydes and formate esters at the catalyst loadings as low as 5–200 p.p.m. Our analysis points to the crucial role of the catalyst activation step for the catalytic performance and stability of the system. While conventional activation employing alkoxide bases can ultimately provide catalytically competent species under hydrogen atmosphere, activation of Mn(I) pre-catalyst with hydride donor promoters, e.g. KHBEt3, dramatically improves catalytic performance of the system and eliminates induction times associated with slow catalyst activation.

scholarly journals A case study of proton shuttling in palladium catalysis

2016 ◽  
Vol 7 (3) ◽  
pp. 2179-2187 ◽  
Author(s):  
Julien Monot ◽  
Paul Brunel ◽  
Christos E. Kefalidis ◽  
Noel Ángel Espinosa-Jalapa ◽  
Laurent Maron ◽  
...  
Keyword(s):  
Palladium Catalysis ◽  
Catalytic Performance ◽  
Pincer Complexes ◽  
Mechanistic Studies ◽  
Proton Shuttling

Thanks to mechanistic studies, the catalytic performance of SCS indenediide Pd pincer complexes has been spectacularly enhanced using catechol additives as proton shuttles.

scholarly journals Mesoporous Palladium N,N’-Bis(3-Allylsalicylidene)o-Phenylenediamine-Methyl Acrylate Resins as Heterogeneous Catalysts for the Heck Coupling Reaction

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2612
Author(s):  
Claudio Mella ◽  
Cecilia C. Torres ◽  
Gina Pecchi ◽  
Cristian H. Campos
Keyword(s):  
Methyl Acrylate ◽  
Heterogeneous Catalysts ◽  
Suspension Polymerization ◽  
Metal Chelate ◽  
Reaction Medium ◽  
Coupling Reaction ◽  
Analytical Techniques ◽  
Catalytic Performance ◽  
Catalyst Stability ◽  
Heck Coupling

Palladium N,N’-bis(3-allylsalicylidene)o-phenylenediamine complex (PdAS) immobilized onto mesoporous polymeric methyl acrylate (MA) based resins (PdAS(x)-MA, x = 1, 2, 5, or 10 wt.%) were successfully prepared as heterogeneous catalysts for the Heck reaction. The catalysts were synthesized via radical suspension polymerization using PdAS as a metal chelate monomer, divinylbenzene and MA as co-monomers. The effect of the PdAS(x) content on the physicochemical properties of the resins is also reported. The catalysts were characterized by using a range of analytical techniques. The large surface area (>580 m2·g−1) and thermal stability (up to 250 °C) of the PdAS(x)-MA materials allows their application as catalysts in the C–C coupling reaction between iodobenzene and MA in the presence of trimethylamine at 120 °C using DMF as the solvent. The PdAS(10)-MA catalyst exhibited the highest catalytic performance with no significant catalytic loss being observed after five reuses, thereby indicating excellent catalyst stability in the reaction medium.

scholarly journals Correction to Enhanced Catalytic Performance of Indenediide Palladium Pincer Complexes for Cycloisomerization: Efficient Synthesis of Alkylidene Lactams

ACS Catalysis ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 1565-1566 ◽  
Author(s):  
Noel Ángel Espinosa-Jalapa ◽  
Diandian Ke ◽  
Noel Nebra ◽  
Lucas Le Goanvic ◽  
Sonia Mallet-Ladeira ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Pincer Complexes ◽  
Efficient Synthesis

Synthesis, characterization and catalytic evaluation in the Heck coupling reactions of S–P–S pincer complexes of the type [Pd{PhP(C6H4-2-S)2}(PAr3)]

2007 ◽  
Vol 360 (6) ◽  
pp. 2128-2138 ◽  
Author(s):  
Valente Gómez-Benítez ◽  
Simón Hernández-Ortega ◽  
Rubén A. Toscano ◽  
David Morales-Morales
Keyword(s):  
Pincer Complexes ◽  
Coupling Reactions ◽  
Heck Coupling

ChemInform Abstract: Catalytic Performance of Symmetrical and Unsymmetrical Sulfur-Containing Pincer Complexes: Synthesis and Tandem Catalytic Activity of the First PCS-Pincer Palladium Complex.

ChemInform ◽  
2008 ◽  
Vol 39 (40) ◽  
Author(s):  
Marcella Gagliardo ◽  
Nicklas Selander ◽  
Nilesh C. Mehendale ◽  
Gerard van Koten ◽  
Robertus J. M. Klein Gebbink ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Palladium Complex ◽  
Catalytic Performance ◽  
Pincer Complexes ◽  
Sulfur Containing

scholarly journals A New Nanomagnetic Pd-Co Bimetallic Alloy as Catalyst in the Mizoroki-Heck and Buchwald–Hartwig Amination Reactions in Aqueous Media

2021 ◽  
Author(s):  
Sara Sobhani ◽  
Hamed Zarei ◽  
José Miguel Sansano
Keyword(s):  
Catalytic Activity ◽  
Reduction Method ◽  
Bimetallic Catalyst ◽  
Aqueous Media ◽  
Catalytic Performance ◽  
Cooperative Effect ◽  
Coupling Reactions ◽  
Heck Coupling ◽  
Bimetallic Alloy ◽  
Amination Reaction

Abstract A Pd-Co bimetallic alloy encapsulated in melamine-based dendrimer supported on magnetic nanoparticles denoted as γ-Fe2O3@MBD/Pd-Co was synthesized by a facile co-complexation-reduction method and characterized sufficiently. The catalytic evaluation of γ-Fe2O3@MBD/Pd-Co showed promising results in the Mizoroki-Heck and Buchwald-Hartwig amination reactions of various iodo-, bromo- and challenging chloroarenes in aqueous media. The synergetic cooperative effect of both Pd and Co and dispersion of the catalyst in water due to the encapsulation of γ-Fe2O3 by melamine-based dendrimer lead to high catalytic performance compared with the monometallic counterparts. The dispersion of the magnetic catalyst also facilitates the recovery and reuse of the catalyst by ten consecutive extraction and final magnetic isolation with no loss of catalytic activity, keeping its structure unaltered. Remarkably, this is the first paper on the use of palladium-cobalt bimetallic catalyst for Buchwald-Hartwig amination reaction and the first magnetically recyclable Pd/Co bimetallic catalyst in the Mizoroki-Heck coupling reactions.

scholarly journals Theoretical Study on CO2 Hydrogenation Mediated by Ru-PNP Pincer Complexes: An Implication Towards Rational Catalyst Design

2021 ◽  
Author(s):  
Shahnaz Rohman ◽  
Chayanika Kashyap ◽  
Amlan Kalita ◽  
Sabnam Ullah ◽  
Indrani Baruah ◽  
...  
Keyword(s):  
Density Functional ◽  
Activation Barrier ◽  
Co2 Reduction ◽  
Catalytic Efficiency ◽  
Catalytic Performance ◽  
Catalyst Design ◽  
Pincer Complexes ◽  
Functional Theory ◽  
Strain Model ◽  
Rational Catalyst Design

Catalytic CO2 reduction mediated by Ru-PNP pincer complexes has been studied using density functional theory (DFT). Calculations clearly reveal that modification of the PNP pincer framework by introducing planar conjugation in the backbone improves the catalytic efficiency. Activation strain model reveals that reduction of strain in the transition states with modified PNP framework associated with the insertion of CO2 molecule is responsible for lowering the activation barrier. Calculations also reveal that electron withdrawing substituents at the PNP ligand improves the catalytic performance.

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