Iridium alkoxide and amide hydride complexes. Synthesis, reactivity, and the mechanism of oxygen-hydrogen and nitrogen-hydrogen reductive elimination

1991 ◽  
Vol 10 (5) ◽  
pp. 1462-1479 ◽  
Author(s):  
David S. Glueck ◽  
Linda J. Newman. Winslow ◽  
Robert G. Bergman
1998 ◽  
Vol 53 (5-6) ◽  
pp. 587-598 ◽  
Author(s):  
Hans-Friedrich Klein ◽  
Stefan Haller ◽  
Hongjian Sun ◽  
Xiaoyan Li ◽  
Thomas Jung ◽  
...  

Abstract Salicylaldehyde derivatives and related β-hydroxo aldehydes CHO-CR=CR′-OH react with CoMe(PMe3)4 via oxidative substitution to form low-spin d6 complexes mer-CoH(CO-CR=CR-O)(PMe3)3. Reductive elimination of acyl and hydride functions from cis positions at the metal is less favourable than in carbonyl cobalt intermediates through a pronounced stabilization by neutral phosphane σ-donor and dianionic acylenolato chelate ligands. Reactions of the hydride complexes with iodomethane or with protic acids HX afford octahedral molecular complexes mer-CoX(CO-CR=CR′-O)(PMe3)3 (X =I, OAc) and mer-CoX(CO-CR=CR′-O)(PMe3)2 (X = OAc, O-CR′=CR-CHO) without opening of the acylenolato chelate ring.


1995 ◽  
Vol 14 (12) ◽  
pp. 5677-5685 ◽  
Author(s):  
Anthony D. Selmeczy ◽  
William D. Jones ◽  
Robert Osman ◽  
Robin Perutz

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>


Author(s):  
Ming Huang ◽  
Yinwu Li ◽  
Xiao-Bing Lan ◽  
Jiahao Liu ◽  
Cunyuan Zhao ◽  
...  

Metal hydride complexes are key intermediates for N-alkylation of amines with alcohols by borrowing hydrogen/hydrogen autotransfer (BH/HA) strategy. Reactivity tuning of metal hydride complexes could adjust the dehydrogenation of alcohols...


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.


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