Efficient Copolymerization of Acrylate and Ethylene with Neutral P, O-Chelated Nickel Catalysts: Mechanistic Investigations of Monomer Insertion and Chelate Formation

2021 ◽  
Author(s):  
Shuoyan Xiong ◽  
Manar M. Shoshani ◽  
Xinglong Zhang ◽  
Heather A. Spinney ◽  
Alex J. Nett ◽  
...  
Keyword(s):  
Nickel Catalysts ◽  
Chelate Formation ◽  
Mechanistic Investigations

Three-Component [1+1+1] Cyclopropanation with Ruthenium(II)

2018 ◽  
Author(s):  
Tanner C. Jankins ◽  
Robert R. Fayzullin ◽  
Eugene Khaskin
Keyword(s):  
Quaternary Carbon ◽  
Poor Control ◽  
One Step ◽  
Synthetic Routes ◽  
Mechanistic Investigations ◽  
Chiral Centers ◽  
Metal Catalyzed ◽  
The Right ◽  
Substituted Cyclopropanes

We report a one-step, Ru(II)-catalyzed cyclopropanation reaction that is conceptually different from the previously reported protocols that include Corey-Chaykovsky, Simmons-Smith, and metal catalyzed carbene attack on olefins. Under the current protocol, various alcohols are transformed into sulfone substituted cyclopropanes with excellent isolated yields and diastereoselectivities. This new reaction forms highly congested cyclopropane products with three new C–C bonds, three or two new chiral centers and one new quaternary carbon center. 22 examples of isolated substrates are given. Previously reported synthetic routes for similar substrates are all multi-step, linear routes that proceed with overall low yields and poor control of stereochemistry. Experimental mechanistic investigations suggest initial metal-catalyzed dehydrogenation of the alcohol substrate and catalyst independent stepwise attack of two equivalents of sulfone on the aldehyde under basic conditions. While the Ru(II) is only responsible for the initial dehydrogenation step, the rate of aldehyde formation is crucial to maintaining the right balance of intermediates needed to afford the cyclopropane product.

Visible Light-Induced Sulfonylation/Arylation of Styrenes in a Double Radical Three-Component Photoredox Reaction

2019 ◽  
Author(s):  
Benjamin Lipp ◽  
Lisa Marie Kammer ◽  
Murat Kucukdisli ◽  
Adriana Luque ◽  
Jonas Kühlborn ◽  
...  
Keyword(s):  
Visible Light ◽  
Radical Formation ◽  
Three Component Reaction ◽  
Broad Variety ◽  
Styrene Derivatives ◽  
Mechanistic Investigations

Simultaneous sulfonylation/arylation of styrene derivatives is achieved in a photoredox-catalyzed three-component reaction using visible light. A broad variety of difunctionalized products is accessible in mostly excellent yields and high diastereoselectivity. The developed reaction is scalable and suitable for the modification of styrene-functionalized biomolecules. Mechanistic investigations suggest the transformation to be operating through a designed sequence of radical formation and radical combination.<br>

Pre-reforming of Liquefied Petroleum Gas over Magnesium Aluminum Mixed Oxide Supported Nickel Catalysts

2013 ◽  
Vol 33 (7) ◽  
pp. 1176-1182
Author(s):  
Xinxing WANG ◽  
Xueguang WANG ◽  
Xingfu SHANG ◽  
Wangxin NIE ◽  
Xiujing ZOU ◽  
...  
Keyword(s):  
Mixed Oxide ◽  
Nickel Catalysts ◽  
Liquefied Petroleum Gas ◽  
Supported Nickel Catalysts

Gas chromatographic study of the sorption of C1-C3 alkanes on nickel catalysts

1969 ◽  
Vol 34 (9) ◽  
pp. 2652-2661
Author(s):  
L. Scháněl ◽  
P. Schneider ◽  
V. Bažant
Keyword(s):  
Nickel Catalysts ◽  
Chromatographic Study

On hydrogenation and dehydrogenation catalysts. XI. Influence of the degree of reduction on the activity and selectivity of nickel catalysts in hydrogenations of alkines

1973 ◽  
Vol 38 (8) ◽  
pp. 2466-2471 ◽  
Author(s):  
V. Růžička ◽  
V. Zapletal ◽  
A. Koppová ◽  
J. Soukup
Keyword(s):  
Nickel Catalysts ◽  
Degree Of Reduction

Catalyst Selection for Hydrogenation of 1,2-Dihydroacenaphthylene

1998 ◽  
Vol 63 (11) ◽  
pp. 1945-1953 ◽  
Author(s):  
Jiří Hanika ◽  
Karel Sporka ◽  
Petr Macoun ◽  
Vladimír Kysilka
Keyword(s):  
Activation Energy ◽  
Nickel Catalyst ◽  
Palladium Catalyst ◽  
Active Component ◽  
Reaction Order ◽  
Nickel Catalysts ◽  
Practical Application ◽  
Repeated Use ◽  
Selection For ◽  
Catalyst Selection

The activity of ruthenium, palladium, and nickel catalysts for the hydrogenation of 1,2-dihydroacenaphthylene in cyclohexane solution was studied at temperatures up to 180 °C and pressures up to 8 MPa. The GC-MS technique was used to identify most of the perhydroacenaphthylene stereoisomers, whose fractions in the product were found dependent on the nature of the active component of the catalyst. The hydrogenation was fastest on the palladium catalyst (3% Pd/C). The nickel catalyst Ni-NiO/Al2O3, which is sufficiently active also after repeated use, can be recommended for practical application. The activation energy of 1,2-dihydroacenaphthylene hydrogenation using this catalyst is 17 kJ/mol, the reaction order with respect to hydrogen is unity.

scholarly journals Reaction-Based Mechanistic Investigations of Asymmetric Hetero-Diels-Alder Reactions of Enones with Isatins Catalyzed by Amine-Based Three-Component Catalyst Systems

2015 ◽  
Vol 5 (1) ◽  
pp. 153-161 ◽  
Author(s):  
Hai-Lei Cui ◽  
Pandurang V. Chouthaiwale ◽  
Feng Yin ◽  
Fujie Tanaka
Keyword(s):  
Diels Alder ◽  
Mechanistic Investigations ◽  
Catalyst Systems
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