Synthesis, Structure, and Reductive Elimination of Cationic Monoarylpalladium(IV) Complexes Supported by a Tripodal Oxygen Ligand

2017 ◽  
Vol 2017 (22) ◽  
pp. 2928-2935 ◽  
Author(s):  
Yat-Ming So ◽  
Ka-Chun Au-Yeung ◽  
Herman H. -Y. Sung ◽  
Ian D. Williams ◽  
Wa-Hung Leung
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):  
Min Zhou ◽  
Jet Tsien ◽  
Tian Qin

<p>Herein we report a sulfur (IV) mediated cross-coupling for facile synthesis of heteroaromatic substrates. Addition of heteroaryl nucleophiles onto a simple, readily-accessible alkyl sulfinyl (IV) chloride allows formation of a trigonal bipyramidal sulfurane intermediate. Reductive elimination therefrom provides bis-heteroaryl products in a practical and efficient fashion. <br></p>


2019 ◽  
Author(s):  
Randolph Escobar ◽  
Jeffrey Johannes

<div>While carbon-heteroatom cross coupling reactions have been extensively studied, many methods are specific and</div><div>limited to a set of substrates or functional groups. Reported here is a method that allows for C-O, C-N and C-S cross coupling reactions under one general methodology. We propose that an energy transfer pathway, in which an iridium photosensitizer produces an excited nickel (II) complex, is responsible for the key reductive elimination step that couples aryl halides to 1° and 2° alcohols, anilines, thiophenols, carbamates and sulfonamides.</div>


2021 ◽  
Author(s):  
Yichen Yu ◽  
Chenxu Wang ◽  
Liqi Wang ◽  
Cai-Li Sun ◽  
Roman Boulatov ◽  
...  

The influence of mechanical force on the rates of model reductive elimination reactions depends on the structure of the force-transducing ligand and provides a measure of geometry changes upon reaching the transition state.


2015 ◽  
Vol 6 (8) ◽  
pp. 4737-4751 ◽  
Author(s):  
Christian P. Sindlinger ◽  
Andreas Stasch ◽  
Holger F. Bettinger ◽  
Lars Wesemann

Amine bases are shown to induce reductive elimination of dihydrogen from terphenyltin trihydride.


1982 ◽  
Vol 104 (2) ◽  
pp. 619-621 ◽  
Author(s):  
Mario J. Nappa ◽  
Roberto Santi ◽  
Steven P. Diefenbach ◽  
Jack Halpern

2009 ◽  
Vol 87 (1) ◽  
pp. 110-120 ◽  
Author(s):  
Julia R Khusnutdinova ◽  
Peter Y Zavalij ◽  
Andrei N Vedernikov

Oxidation of phenyl PtII complexes K[(dpms)PtIIPh2], 1, (dpms)PtIIPh(MeOH), 2, (dpms)PtIIPh(OH2), 3, and methyl PtII complex (dpms)PtIIMe(NH2Ph), 6, with O2 in aqueous or methanol solutions under ambient conditions leads to corresponding (dpms)PtIVR(X)OH complexes (R = X = Ph, 7; R = Ph, X = OH, 8; R = Ph, X = OMe, 9; R = Me, X = NHPh; 11; dpms = di(2-pyridyl)methanesulfonate). Complexes 7–9 could be isolated in high yield. Complex 11 as well as its phenyl analogue (dpms)PtIVPh(NHPh)OH, 10 can be prepared in high yield by oxidation of corresponding (dpms)PtIIR(NH2Ph) with H2O2 in methanol. Phenyl PtII complexes (dpms)PtIIPh(HX) derived from HX = aniline and DMSO, 4 and 5, respectively, are inert toward O2. The rate of oxidation of 1–5 with O2 decreases in the order 1 > 3 ~ 2 » 4, and 5 is unreactive. Methyl analogues are significantly more reactive compared with their phenyl counterparts. Proposed mechanism of oxidation with O2 includes formation of anionic species (dpms)PtIIR(X)– responsible for reaction with dioxygen. Attempts at C–O and C–N reductive elimination from phenyl PtIV complexes 7–10 do not lead to phenyl derivatives PhX at 80–100 °C, consistent with the results of the DFT estimates of corresponding activation barriers, ΔG0 exceeding 28 kcal/mol.Key words: platinum phenyl complexes, oxidation, dioxygen, aqueous solution, mechanism.


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