Oxidative Addition of Aryl Sulfonates to Palladium(0) Complexes of Mono- and Bidentate Phosphines. Mild Addition of Aryl Tosylates and the Effects of Anions on Rate and Mechanism

2004 ◽  
Vol 23 (2) ◽  
pp. 194-202 ◽  
Author(s):  
Amy H. Roy ◽  
John F. Hartwig
Keyword(s):  
Oxidative Addition ◽  
Aryl Tosylates

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

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>

Dual Nickel/Palladium-Catalyzed Reductive Cross-Coupling Reactions Between Two Phenol Derivatives

2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian
Keyword(s):  
Functional Group ◽  
Low Cost ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Phenol Derivatives ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
One Step ◽  
Aryl Tosylates ◽  
Low Sensitivity

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.

Ni(0)-Catalyzed α-Allylic Alkylation of Regular Ketones with 1,3-Dienes under pH and Redox-neutral Conditions

2019 ◽  
Author(s):  
Tiantian Chen ◽  
Yang Yang ◽  
Liyu Xie ◽  
Haijian Yang ◽  
Guangbin Dong ◽  
...  
Keyword(s):  
Oxidative Addition ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Dual Role ◽  
Allylic Alkylation ◽  
Cross Coupling Reaction ◽  
Neutral Conditions

<p>We report a Ni(0)-catalyzed cross coupling reaction between simple ketones and 1,3-dienes. A variety of a-allylic alkylation products were formed in an 1,2-addition manner with excellent regioselectivity. Water was found to significantly accelerate this transformation. A HO-Ni-H species generated from oxidative addition of Ni(0) to H<sub>2</sub>O is proposed to play a “dual role” in activating both the ketone and the diene substrate.</p>

On the Reactivity of mRNA Caps: C-H Oxidative Addition of 7-Methylguanosine to Pt(0)

2019 ◽  
Author(s):  
Maria Ines Leitao ◽  
Carmen Gonzalez ◽  
Zuzanna Filipiak ◽  
Ana Petronilho
Keyword(s):  
Oxidative Addition ◽  
Carbene Complex ◽  
Proton Loss

<p>7-methylguanosine, the so-called mRNA cap 0 bears a very labile C8-H bond, due to the formation of an ylide/N-heterocyclic carbene, upon proton loss. The reaction of 7-methylguanosine with Pt(PPh3)4, via C-H oxidative addition, yields a hydrido–PtII carbene complex and this reactivity can be extrapolated to 7,9-dimethylguanine. </p>

Hydrogen-halide versus alkyl-halide oxidative addition in dimethyl platinum(II) complexes: Crystal structure of [PtBr2(bpy)]

2007 ◽  
Vol 360 (8) ◽  
pp. 2661-2668 ◽  
Author(s):  
Badri Z. Momeni ◽  
Saeideh Hamzeh ◽  
Simin S. Hosseini ◽  
Frank Rominger
Keyword(s):  
Crystal Structure ◽  
Alkyl Halide ◽  
Oxidative Addition ◽  
Hydrogen Halide

Oxidative Addition von BF3 an ein Übergangsmetall

2011 ◽  
Vol 123 (44) ◽  
pp. 10641-10644 ◽  
Author(s):  
Jürgen Bauer ◽  
Holger Braunschweig ◽  
Katharina Kraft ◽  
Krzysztof Radacki
Keyword(s):  
Oxidative Addition
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