Catalytic systems based on nickel(ii) complexes with bis(3,5-dimethylpyrazol-1-yl)methane – impact of PPh3 on the formation of precatalysts and selective dimerization of ethylene

2020 ◽  
Vol 44 (3) ◽  
pp. 981-993 ◽  
Author(s):  
S. V. Zubkevich ◽  
V. A. Tuskaev ◽  
S. Ch. Gagieva ◽  
A. A. Pavlov ◽  
V. N. Khrustalev ◽  
...  

Triphenylphosphine facilities ionization of Ni(ii) complexes with bis(3,5-dimethylpyrazol-1-yl)metane, which results in highly active catalytic systems for ethylene dimerization.

2021 ◽  
Vol 08 ◽  
Author(s):  
Vivek Srivastava

Background: Baylis-Hillman reaction suffers from the requirement of cheap starting materials, easy reaction protocol, possibility to create the chiral center in the reaction product has increased the synthetic efficacy of this reaction, and high catalyst loading, low reaction rate, and poor yield. Objective: The extensive use of various functional or non-functional ionic liquids (ILs) with organocatalyst increases the reaction rate of various organic transformations as a reaction medium and as a support to anchor the catalysts. Methods: In this manuscript, we have demonstrated the synthesis of quinuclidine-supported trimethylamine-based functionalized ionic liquid as a catalyst for the Baylis-Hillman reaction. Results: We obtained the Baylis-Hillman adducts in good, isolated yield, low catalyst loading, short reaction time, broad substrate scope, accessible product, and catalyst recycling. N-((E,3S,4R)-5-benzylidene-tetrahydro-4-hydroxy-6-oxo-2H-pyran-3-yl) palmitamide was also successfully synthesized using CATALYST-3 promoted Baylis-Hillman reaction. Conclusion: We successfully isolated the 25 types of Baylis-Hillman adducts using three different quinuclidine-supported ammonium-based ionic liquids such as Et3AmQ][BF4] (CATALYST-1), [Et3AmQ][PF6] (CATALYST-2), and [TMAAmEQ][NTf2](CATALYST-3) as new and efficient catalysts. Tedious and highly active N-((E,3S,4R)-5-benzylidene-tetrahydro-4-hydroxy-6-oxo-2H-pyran-3-yl) palmitamide derivative was also synthesized using CATALYST-3 followed by Baylis-Hillman reaction. Generally, all the responses demonstrated higher activity and yielded high competition with various previously reported homogenous and heterogeneous Catalytic systems. Easy catalyst and product recovery followed by six catalysts recycling were the added advantages of the prosed catalytic system.


Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2413 ◽  
Author(s):  
Cheng Chen ◽  
Yang Miao ◽  
Kimmy De Winter ◽  
Hua-Jing Wang ◽  
Patrick Demeyere ◽  
...  

Transition-metal-catalyzed amide-bond formation from alcohols and amines is an atom-economic and eco-friendly route. Herein, we identified a highly active in situ N-heterocyclic carbene (NHC)/ruthenium (Ru) catalytic system for this amide synthesis. Various substrates, including sterically hindered ones, could be directly transformed into the corresponding amides with the catalyst loading as low as 0.25 mol.%. In this system, we replaced the p-cymene ligand of the Ru source with a relatively labile cyclooctadiene (cod) ligand so as to more efficiently obtain the corresponding poly-carbene Ru species. Expectedly, the weaker cod ligand could be more easily substituted with multiple mono-NHC ligands. Further high-resolution mass spectrometry (HRMS) analyses revealed that two tetra-carbene complexes were probably generated from the in situ catalytic system.


2015 ◽  
Vol 5 (7) ◽  
pp. 3822-3828 ◽  
Author(s):  
Henrik Gulyás ◽  
Ivan Rivilla ◽  
Simona Curreli ◽  
Zoraida Freixa ◽  
Piet W. N. M. van Leeuwen

Platinum complexes of the chiral non-racemizing SPO ligand 1 have been discovered to be the first artificial transition metal complexes providing kinetic resolution in the hydration of a racemic chiral nitrile.


1995 ◽  
Vol 128 (1) ◽  
pp. 127-141 ◽  
Author(s):  
Jong Rack Sohn ◽  
Hae Won Kim ◽  
Man Young Park ◽  
Eun Hee Park ◽  
Jong Taik Kim ◽  
...  

Author(s):  
Cheng Chen ◽  
Yang Miao ◽  
Kimmy De Winter ◽  
Hua-Jing Wang ◽  
Patrick Demeyere ◽  
...  

Transition-metal-catalyzed amide bond formation from alcohols and amines is an atom-economic and eco-friendly route. Herein, we identified a highly active in situ N-heterocyclic carbene (NHC)/ruthenium (Ru) catalytic system for this amide synthesis. Various substrates, including sterically hindered ones, could be directly transformed into the corresponding amides with the catalyst loading as low as 0.25 mol%. In this system, we replaced the p-cymene ligand of the Ru source with a relatively labile cyclooctadiene (cod) ligand so as to more efficiently obtain the corresponding poly-carbene Ru species. Expectedly, the weaker cod ligand could be more easily substituted with multiple mono-NHC ligands. Further HR-MS analyses revealed that two tetra-carbene complexes were probably generated from the in situ catalytic system.


2017 ◽  
Vol 2 (23) ◽  
pp. 6717-6727 ◽  
Author(s):  
Stanisław Krompiec ◽  
Beata Marcol ◽  
Dawid Zych ◽  
Aneta Kurpanik ◽  
Witold Danikiewicz ◽  
...  

2019 ◽  
Vol 62 (1-2) ◽  
pp. 73-88
Author(s):  
M.D. Smolikov ◽  
V.A. Shkurenok ◽  
S.S. Yablokova ◽  
D.I. Kir’yanov ◽  
A.S. Belyi

The paraffin hydrocarbons isomerization is one of the most important processes in the oil refining industry, aimed at obtaining high-octane environmental components of modern gasolines. The actual direction in isomerization is the processing of the fraction, containing C7-alkanes. The review is devoted to modern concepts of the active rface formation of tungstate-containing zirconia, which is a highly active catalytic system for the isomerization of heptanes. The review deals with the influence of synthesis method of tungstate-containing zirconia, it’s chemical composition, phase structure and acid properties on the formation of the active surface of WO3/ZrO2 systems and their catalytic activity. The role of platinum in the catalytic systems WO3/ZrO2 for C7-alkanes isomerization is considered.


Polyhedron ◽  
2013 ◽  
Vol 52 ◽  
pp. 1138-1144 ◽  
Author(s):  
Peng Hao ◽  
Shengju Song ◽  
Tianpengfei Xiao ◽  
Yan Li ◽  
Carl Redshaw ◽  
...  

ChemInform ◽  
2010 ◽  
Vol 23 (39) ◽  
pp. no-no ◽  
Author(s):  
A. M. AL-JARALLAH ◽  
J. A. ANABTAWI ◽  
M. A. B. SIDDIQUI ◽  
A. M. AITANI ◽  
A. W. AL-SA'DOUN

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