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

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):  
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>


2020 ◽  
Vol 56 (10) ◽  
pp. 1545-1548 ◽  
Author(s):  
Alejandra Gómez-Torres ◽  
J. Rolando Aguilar-Calderón ◽  
Carlos Saucedo ◽  
Aldo Jordan ◽  
Alejandro Metta-Magaña ◽  
...  

The masked Ti(ii) synthon (Ketguan)(η6-ImDippN)Ti (1) undergoes fully reversible oxidative-addition/reductive-elimination with thiophene while also promoting its hydrodesulphurization upon exposure to H2.


2017 ◽  
Vol 72 (11) ◽  
pp. 865-871
Author(s):  
Jürgen Tirrée ◽  
Alexander V. Ruban ◽  
Martin Nieger ◽  
Claudia Li ◽  
László Nyulászi ◽  
...  

AbstractIn a search for stable phosphinonitrenes generated by thermally induced decomposition of the azidophosphines 8a, b, different cyclodiphosp(V)azene products were generated. While in the case of 8a the expected phosphinonitrene dimer 10 could be obtained, from 8b, which has the sterically more demanding TMP substituents, product 11, was obtained and characterized. DFT calculations have revealed that the primarily formed phosphinonitrene 9b is unstable against loss of TMP˙, and the resulting radical dimerizes to the biradicaloid 1,3-diaza-2,4-diphosphetane-2,4-diyl 13. Compound 13 then dimerizes after ring opening, yielding in the ring system, which provides the final product upon reaction with the starting azidophosphine.


2019 ◽  
Vol 9 (3) ◽  
pp. 646-651 ◽  
Author(s):  
Zhaoyuan Yu ◽  
Tao Zhang ◽  
Ruopeng Bai ◽  
Yu Lan

Density functional theory (DFT) calculations indicate that favorable oxidative addition/reductive elimination process from arylrhodium complex determines the enantioselectivity.


2018 ◽  
Vol 47 (8) ◽  
pp. 2662-2669 ◽  
Author(s):  
H.-L. Qin ◽  
J. Leng ◽  
W. Zhang ◽  
E. A. B. Kantchev

DFT calculations confirmed that the rearrangement of a PCP-Rh-H pincer to a CCP-Rh-phosphane pincer occured by C–P oxidative addition (ΔG‡ = 29.5 kcal mol−1, rate-determining step), followed by P–H reductive elimination (ΔG‡ = 4.8 kcal mol−1).


Tetrahedron ◽  
2021 ◽  
pp. 131957
Author(s):  
Mohammed M. Abadleh ◽  
Ahmad H. Abdullah ◽  
Firas F. Awwadi ◽  
Mustafa M. El-Abadelah

2021 ◽  
Author(s):  
Payam Abdolalian ◽  
Samaneh K. Tizhoush ◽  
Kaveh Farshadfar ◽  
Alireza Ariafard

This work uses DFT calculations to explore Pd(ii)-catalysed iodine(iii)-mediated alkoxylation of unactivated C(sp3)–H bonds and reveals how important the isomerization is in triggering the oxidative addition of ArIX2 to Pd(ii).


2013 ◽  
Vol 125 (11) ◽  
pp. 3309-3313 ◽  
Author(s):  
Mario Carrasco ◽  
Natalia Curado ◽  
Celia Maya ◽  
Riccardo Peloso ◽  
Amor Rodríguez ◽  
...  

2021 ◽  
Author(s):  
Jun Okuda ◽  
Louis J. Morris ◽  
Laurent Maron ◽  
Ambre Carpentier

Oxidative addition of TMEDA-supported [AlH2]+ to [{BDI}Ga] (BDI = {HC(C(CH3)N(2,6-iPr2-C6H3))2) provides [{BDI}Ga(H)-Al(H)(tmeda)]¬[B(C6H3-3,5-Me2)4] (TMEDA = N,N,N’N’-tetramethylethylene¬diamine) with a covalent metal-metal bond. The reaction is readily reversed by substituting TMEDA for an...


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