Hydrofluoroarylation of Alkynes with Ni Catalysts. C–H Activation via Ligand-to-Ligand Hydrogen Transfer, an Alternative to Oxidative Addition

2011 ◽  
Vol 31 (4) ◽  
pp. 1300-1314 ◽  
Author(s):  
Julie Guihaumé ◽  
Stéphanie Halbert ◽  
Odile Eisenstein ◽  
Robin N. Perutz
Keyword(s):  
Hydrogen Transfer ◽  
Oxidative Addition ◽  
Ni Catalysts

scholarly journals Insights into metal–ligand hydrogen transfer: a square-planar ruthenate complex supported by a tetradentate amino–amido-diolefin ligand

2016 ◽  
Vol 52 (36) ◽  
pp. 6138-6141 ◽  
Author(s):  
Demyan E. Prokopchuk ◽  
Alan J. Lough ◽  
Rafael E. Rodriguez-Lugo ◽  
Robert H. Morris ◽  
Hansjörg Grützmacher
Keyword(s):  
Hydrogen Transfer ◽  
Oxidative Addition ◽  
Square Planar ◽  
Elimination Reactions ◽  
Metal Ligand

A unique square planar anionic ruthenium(0) complex with amido and amine donors undergoes rapid NH oxidative addition/elimination reactions.

Iridaoxacyclohexadiene-Bridged Mixed-Valence Iridium Cyclooctadiene Complex: Oxidative Addition and Hydrogen-Transfer to Coordinated Cyclooctadiene

2014 ◽  
Vol 33 (22) ◽  
pp. 6305-6318 ◽  
Author(s):  
Itzia Irene Padilla-Martínez ◽  
Marisol Cervantes-Vásquez ◽  
Marco Antonio Leyva-Ramirez ◽  
M. Angeles Paz-Sandoval
Keyword(s):  
Hydrogen Transfer ◽  
Mixed Valence ◽  
Oxidative Addition

scholarly journals Synthesis of chiral supramolecular bisphosphinite palladacycles through hydrogen transfer-promoted self-assembly process

2018 ◽  
Vol 54 (72) ◽  
pp. 10132-10135 ◽  
Author(s):  
Alexandre Vasseur ◽  
Romain Membrat ◽  
Davide Palpacelli ◽  
Michel Giorgi ◽  
Didier Nuel ◽  
...  
Keyword(s):  
Self Assembly ◽  
Acidic Medium ◽  
Hydrogen Transfer ◽  
Oxidative Addition ◽  
Secondary Phosphine ◽  
Assembly Process ◽  
Phosphine Oxides

P-Chiral secondary phosphine oxides react with Pd2(dba)3 in an acidic medium to provide chiral supramolecular bisphosphinite palladacycles through a H-transfer-based self-assembly process prior to SPO-promoted oxidative addition of an acid to a Pd(0) centre.

scholarly journals Understanding the unique reactivity patterns of nickel/JoSPOphos manifold in the nickel-catalyzed enantioselective C–H cyclization of imidazoles

2021 ◽  
Author(s):  
Jian-Biao Liu ◽  
Xin Wang ◽  
Antonis M. Messinis ◽  
Xiao-Jun Liu ◽  
Rositha Kuniyil ◽  
...  
Keyword(s):  
Hydrogen Transfer ◽  
Oxidative Addition ◽  
Cam Mechanism ◽  
Migratory Insertion

Several unique reactivity patterns of the Ni/JoSPOphos manifold, including facile hydrogen transfer via the two-step oxidative addition/migratory insertion and C(sp2)–H activation via an unconventional σ-CAM mechanism, were disclosed in this work.

Effect of Niacin on Mitochondria of Allium Cepa Root Cells

1967 ◽  
Vol 25 ◽  
pp. 78-79
Author(s):  
M. Arif Hayat
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Hydrogen Transfer ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Root Tips ◽  
Root Cells ◽  
Transfer Processes ◽  
Standard Procedures ◽  
A Cell ◽  
Critical Interest

Although it is recognized that niacin (pyridine-3-carboxylic acid), incorporated as the amide in nicotinamide adenine dinucleotide (NAD) or in nicotinamide adenine dinucleotide phosphate (NADP), is a cofactor in hydrogen transfer in numerous enzyme reactions in all organisms studied, virtually no information is available on the effect of this vitamin on a cell at the submicroscopic level. Since mitochondria act as sites for many hydrogen transfer processes, the possible response of mitochondria to niacin treatment is, therefore, of critical interest.Onion bulbs were placed on vials filled with double distilled water in the dark at 25°C. After two days the bulbs and newly developed root system were transferred to vials containing 0.1% niacin. Root tips were collected at ¼, ½, 1, 2, 4, and 8 hr. intervals after treatment. The tissues were fixed in glutaraldehyde-OsO4 as well as in 2% KMnO4 according to standard procedures. In both cases, the tissues were dehydrated in an acetone series and embedded in Reynolds' lead citrate for 3-10 minutes.

Some Problems in the Oxidative Addition and Binding of an Ethylene to a Transition Metal Center.

1987 ◽  
Vol 6 (4) ◽  
pp. 902-902
Author(s):  
Jerome Silestre ◽  
Maria Calhorda ◽  
Roald Hoffman ◽  
Page Stoutland ◽  
Robert Bergman
Keyword(s):  
Transition Metal ◽  
Oxidative Addition ◽  
Metal Center

STRUCTURE AND CATALYTICAL INVESTIGATION OF Fe-Mo AND Fe-Ni CATALYSTS FOR AMMONIS SYNTHESIS

1980 ◽  
Vol 41 (C1) ◽  
pp. C1-337-C1-337
Author(s):  
Yu. V. Maksimov ◽  
R. Arents ◽  
I. P. Suzdalev ◽  
V. K. Yatsimirski
Keyword(s):  
Ni Catalysts

Reversible Oxidative-Addition and Reductive-Elimination of Thiophene from a Titanium Complex and Its Thermally-Induced Hydrodesulfurization Chemistry

2019 ◽  
Author(s):  
Alejandra Gomez-Torres ◽  
J. Rolando Aguilar-Calderón ◽  
Carlos Saucedo ◽  
Aldo Jordan ◽  
Alejandro J. Metta-Magaña ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Ring Opening ◽  
Thiophene Ring ◽  
Oxidative Addition ◽  
Reductive Elimination ◽  
Thermally Induced ◽  
Titanium Complex

<p>The masked Ti(II) synthon (<sup>Ket</sup>guan)(<i>η</i><sup>6</sup>-Im<sup>Dipp</sup>N)Ti (<b>1</b>) oxidatively adds across thiophene to give ring-opened (<sup>Ket</sup>guan)(Im<sup>Dipp</sup>N)Ti[<i>κ</i><sup>2</sup>-<i>S</i>(CH)<sub>3</sub><i>C</i>H] (<b>2</b>). Complex <b>2</b> is photosensitive, and upon exposure to light, reductively eliminates thiophene to regenerate <b>1</b> – a rare example of early-metal mediated oxidative-addition/reductive-elimination chemistry. DFT calculations indicate strong titanium π-backdonation to the thiophene π*-orbitals leads to the observed thiophene ring opening across titanium, while a proposed photoinduced LMCT promotes the reverse thiophene elimination from <b>2</b>. Finally, pressurizing solutions of <b>2 </b>with H<sub>2</sub> (150 psi) at 80 °C leads to the hydrodesulfurization of thiophene to give the Ti(IV) sulfide (<sup>Ket</sup>guan)(Im<sup>Dipp</sup>N)Ti(S) (<b>3</b>) and butane. </p>

Cobalt/Lewis Acid Catalysis for Hydrocarbofunctionalization of Alkynes via Cooperative C–H Activation

2020 ◽  
Author(s):  
Chang-Sheng Wang ◽  
Sabrina Monaco ◽  
Anh Ngoc Thai ◽  
Md. Shafiqur Rahman ◽  
Chen Wang ◽  
...  
Keyword(s):  
Catalytic System ◽  
Lewis Acid ◽  
Hydrogen Transfer ◽  
Acid Catalysis ◽  
Rate Limiting Step ◽  
Site Selectivity ◽  
Set Up ◽  
Site Selective ◽  
First Time ◽  
Rate Limiting

A catalytic system comprised of a cobalt-diphosphine complex and a Lewis acid (LA) such as AlMe3 has been found to promote hydrocarbofunctionalization reactions of alkynes with Lewis basic and electron-deficient substrates such as formamides, pyridones, pyridines, and azole derivatives through site-selective C-H activation. Compared with known Ni/LA catalytic system for analogous transformations, the present catalytic system not only feature convenient set up using inexpensive and bench-stable precatalyst and ligand such as Co(acac)3 and 1,3-bis(diphenylphosphino)propane (dppp), but also display distinct site-selectivity toward C-H activation of pyridone and pyridine derivatives. In particular, a completely C4-selective alkenylation of pyridine has been achieved for the first time. Mechanistic stidies including DFT calculations on the Co/Al-catalyzed addition of formamide to alkyne have suggested that the reaction involves cleavage of the carbamoyl C-H bond as the rate-limiting step, which proceeds through a ligand-to-ligand hydrogen transfer (LLHT) mechanism leading to an alkyl(carbamoyl)cobalt intermediate.

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