Reversible oxidative addition and reductive elimination of diaryl sulphide involving C–S bond cleavage and formation: exchange of two aryl groups in aryl(arylthiolato)nickel complexes having tertiary phosphine ligands

1986 ◽  
pp. 442-443 ◽  
Author(s):  
Kohtaro Osakada ◽  
Meguru Maeda ◽  
Yoshiyuki Nakamura ◽  
Takakazu Yamamoto ◽  
Akio Yamamoto
Keyword(s):  
Bond Cleavage ◽  
Oxidative Addition ◽  
Nickel Complexes ◽  
Reductive Elimination ◽  
Phosphine Ligands ◽  
Tertiary Phosphine

Crystal Structure and Ligand Mobility in Solution of cis-Dimethyl-bis(trimethylphosphine)gold(III) Complexes

2006 ◽  
Vol 61 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Oliver Schuster ◽  
Hubert Schmidbaur
Keyword(s):  
Crystal Structure ◽  
Reductive Elimination ◽  
Unit Cell ◽  
Phosphine Ligands ◽  
Thermally Stable ◽  
Tertiary Phosphine ◽  
Trans Influence ◽  
Solvent Molecules ◽  
Perchlorate Salt

Complexes [Me2Au(PMe3)2]+ X− with X = I and ClO4 have been prepared by several conventional routes in good yields. The products are thermally stable and decompose above 130 °C with reductive elimination of ethane. The two salts crystallize as isomorphous orthorhombic dichloromethane solvates. The cations have the cis-configuration based on a crystallographically imposed C2v symmetry. Owing to the trans influence of the tertiary phosphine ligands the Au-C bonds are significantly shorter than in standard reference cases. The cations are stacked in pairs of columns running parallel to the c axis of the unit cell with the Me2Au units oriented in opposite directions and slightly interlocked. The anions are inserted into the pockets formed by the four Me3P groups of each pair of neighbouring cations in the same column. The large channels between the double columns are filled by the solvent molecules, which could be localized for the perchlorate salt, but were disordered and deficient in the iodide case.

Probing enantioselectivity in rhodium-catalyzed Si–C bond cleavage to construct silicon-stereocenters: a theoretical study

2019 ◽  
Vol 9 (3) ◽  
pp. 646-651 ◽  
Author(s):  
Zhaoyuan Yu ◽  
Tao Zhang ◽  
Ruopeng Bai ◽  
Yu Lan
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Density Functional ◽  
Theoretical Study ◽  
Bond Cleavage ◽  
Oxidative Addition ◽  
Reductive Elimination ◽  
Functional Theory ◽  
Elimination Process

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

Oxidative Addition of Functionalized Alkyl-Halides to Iridium(I) Complexes IrCl(Co)L2 (L = PMe2Ph2>, IrCl(Co)PMe3)

1986 ◽  
Vol 39 (9) ◽  
pp. 1363 ◽  
Author(s):  
MA Bennett ◽  
GT Crisp
Keyword(s):  
Carbon Atom ◽  
Oxidative Addition ◽  
Alkyl Halides ◽  
Phosphine Ligands ◽  
Tertiary Phosphine ◽  
Reverse Process ◽  
Alkyl Bromides ◽  
Electron Withdrawing Substituents

Iridium(I) complexes IrCl (CO)L2 (L = PMePh2, PMe2Ph, PMe3) oxidatively add alkyl bromides RBr bearing electron-withdrawing substituents on the α-carbon atom (R = CH2CO2Et,CH3CHCO2Et,CH3CHCOCH3,C2H5CHNO2) to give octahedrally coordinated alkyliridium (III) complexes IrBrClR (CO)L2, for which 1H and 31P n.m.r . data are reported. In the secondary alkyls, the mutually trans tertiary phosphine ligands are inequivalent, consequently the P-Me resonance is not the usual 1 : 2 : 1 'virtual' triplet. In some cases the pattern is a doublet or a doublet of doublets, similar to that expected for mutually cis tertiary phosphine ligands . In contrast to simple s- alkyliridium (III) complexes, the functionalized s-alkyls do not isomerize under any conditions to the corresponding n-alkyls, and the reverse process does not occur for n-alkyls such as IrBrCl (CH2CH2CO2Et)(CO)(PMe3)2 and IrClI (CH2CH2CN)(CO)(PMe3)2. Diiodomethane and chloroiodomethane readily add to IrCl (CO)L2 to give haloalkyliridium (III) complexes IrClI (CH2Y)(CO)L2(Y = Cl , I). These contain mutually trans tertiary phosphine ligands , although in the case of L = PMe2Ph unstable cis - isomers can be detected. Attempts to form complexes containing Ir - CHBrCH3 or Ir -CH(OC2H5)CH3 by addition of CH3CHBr2 or CH3CHClOC2H5 to IrCl (CO)(PMe3)2 gave only IrBr2Cl(CO)(PMe3)2 and IrHCl2(CO)(PMe3)2, respectively.

A dual light-driven palladium catalyst: Breaking the barriers in carbonylation reactions

Science ◽  
2020 ◽  
Vol 368 (6488) ◽  
pp. 318-323 ◽  
Author(s):  
Gerardo M. Torres ◽  
Yi Liu ◽  
Bruce A. Arndtsen
Keyword(s):  
Bond Cleavage ◽  
Oxidative Addition ◽  
Reductive Elimination ◽  
Coupling Reactions ◽  
Ambient Conditions ◽  
Inherent Limitation ◽  
Carbonyl Derivatives ◽  
Palladium Catalyzed ◽  
Light Excitation ◽  
Metal Catalyzed

Transition metal–catalyzed coupling reactions have become one of the most important tools in modern synthesis. However, an inherent limitation to these reactions is the need to balance operations, because the factors that favor bond cleavage via oxidative addition ultimately inhibit bond formation via reductive elimination. Here, we describe an alternative strategy that exploits simple visible-light excitation of palladium to drive both oxidative addition and reductive elimination with low barriers. Palladium-catalyzed carbonylations can thereby proceed under ambient conditions, with challenging aryl or alkyl halides and difficult nucleophiles, and generate valuable carbonyl derivatives such as acid chlorides, esters, amides, or ketones in a now-versatile fashion. Mechanistic studies suggest that concurrent excitation of palladium(0) and palladium(II) intermediates is responsible for this activity.

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