ChemInform Abstract: Oxidatively Induced Reductive Elimination. A Novel Titanium Complex Resulting from C-F Bond Activation.

ChemInform ◽  
1990 ◽  
Vol 21 (48) ◽  
Author(s):  
M. J. BURK ◽  
D. L. STALEY ◽  
W. TUMAS
2019 ◽  
Author(s):  
Alejandra Gomez-Torres ◽  
J. Rolando Aguilar-Calderón ◽  
Carlos Saucedo ◽  
Aldo Jordan ◽  
Alejandro J. Metta-Magaña ◽  
...  

<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>


2019 ◽  
Author(s):  
Dengmengfei Xiao ◽  
Lili Zhao ◽  
Diego Andrada

Unstrained cyclic ketones can participate in cooperative Suzuki-Miyaura cross-coupling type reaction using rhodium(I)-based catalyst via C-C bond activation. The regioselectivity indicates a trend where the most substituted side is activated and it is controlled by the beta-substituents. In this work, Density Functional Theory (DFT) calculations have been carried out to disclose the underlying mechanism in the reaction of a ketone series and arylboronate using ylidene as ancillary ligand and pyridine as co-catalysts. The computed energies suggest the reductive elimination step with the highest energy while the reductive elimination has the highest energy barrier. By the means of the Activation Strain Model (ASM) of chemical reactivity, it is found that the ketone strain energy released on the oxidative addition does not control the relativity of the OA reactivity, but indeed is the interaction energy between Rh(I) and C-C bond the ruling effect. The effect of the beta-substituents on regioselectivity has been additionally studied.


2020 ◽  
Vol 142 (52) ◽  
pp. 21679-21690
Author(s):  
Dmitriy A. Lukoyanov ◽  
Zhi-Yong Yang ◽  
Dennis R. Dean ◽  
Lance C. Seefeldt ◽  
Simone Raugei ◽  
...  

2012 ◽  
Vol 31 (12) ◽  
pp. 4401-4404 ◽  
Author(s):  
Margarita Crespo ◽  
Craig M. Anderson ◽  
Nicole Kfoury ◽  
Mercè Font-Bardia ◽  
Teresa Calvet

Synlett ◽  
2018 ◽  
Vol 29 (16) ◽  
pp. 2087-2092 ◽  
Author(s):  
Gui Chen ◽  
Xueliang Huang ◽  
Yinghua Yu

Palladium-catalyzed annulation of ortho-bromobenzaldehydes with aryl diazoesters is achieved via a sequence of palladium carbene migratory insertion, acyl C–H bond activation and reductive elimination of a seven-membered palladacyclic intermediate. A variety of isocoumarin derivatives were furnished in a straightforward manner.


Sign in / Sign up

Export Citation Format

Share Document