Reduction–oxidation properties of organotransition-metal complexes. Part 31. Reductive elimination, oxidative addition and substitution, and migratory insertion in pentaphenylcyclopentadienylruthenium nitrosyl chemistry

Alk-1-ynes (RC2H; R = H, Pr, Bu, CH2CH2OH, Ph, CO2Me) undergo irreversible oxidative addition to the iridium(I) complex IrCl(PPh3)3 to give six-coordinate hydrido acetylides of iridium(III), IrHCl(C2R)(PPh3)3, the stereochemistry of which is deduced from 1H N.M.R. and infrared data. Isomers of the corresponding adduct of phenylacetylene with IrCl(PMePh2)3 can be isolated. Carbonylation of IrHCl(C2R)(PPh3)3 gives IrHCl(C2R)(CO)(PPh3)2, which can be isolated only when R = H, Ph or CO2Me; when R = Pr, Bu or CH2CH2OH, the complexes immediately decompose to IrCl(CO)(PPh3)2 and the alkyne. This reductive elimination also occurs to some extent for R = Ph. Diphenylacetylene and dimethyl acetylenedicarboxylate react with IrCl(PPh3)3 to give the known alkyne complex IrCl(PhC2Ph)(PPh3)2 and the known iridiacyclopentadiene complex IrCl-(MeO2CC2CO2Me)2(PPh3)2 respectively. The additions of alk-1-ynes to IrClL3 and to other lowvalent metal complexes are compared, and the relevance of the oxidative addition to catalysis of linear polymerization of alk-1-ynes is noted.

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Solution calorimetric, equilibrium, and synthetic studies of oxidative addition/reductive elimination of cyclopentadiene derivatives, C5R5H (R = H, Me, indenyl), to/from the metal complexes M(CO)3(RCN)3/(*5-C5R5)M(CO)3H (M = chromium, molybdenum, tungsten)

Organometallics ◽

10.1021/om00054a062 ◽

1991 ◽

Vol 10 (8) ◽

pp. 2870-2876 ◽

Cited By ~ 24

Author(s):

Gregory J. Kubas ◽

Gabor. Kiss ◽

Carl D. Hoff

Keyword(s):

Metal Complexes ◽

Oxidative Addition ◽

Reductive Elimination ◽

Synthetic Studies

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

10.26434/chemrxiv.10321946.v1 ◽

2019 ◽

Author(s):

Alejandra Gomez-Torres ◽

J. Rolando Aguilar-Calderón ◽

Carlos Saucedo ◽

Aldo Jordan ◽

Alejandro J. Metta-Magaña ◽

...

Keyword(s):

Dft Calculations ◽

Ring Opening ◽

Thiophene Ring ◽

Oxidative Addition ◽

Reductive Elimination ◽

Thermally Induced ◽

Titanium Complex

The masked Ti(II) synthon (Ketguan)(η6-ImDippN)Ti (1) oxidatively adds across thiophene to give ring-opened (Ketguan)(ImDippN)Ti[κ2-S(CH)3CH] (2). Complex 2 is photosensitive, and upon exposure to light, reductively eliminates thiophene to regenerate 1 – 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 2. Finally, pressurizing solutions of 2 with H2 (150 psi) at 80 °C leads to the hydrodesulfurization of thiophene to give the Ti(IV) sulfide (Ketguan)(ImDippN)Ti(S) (3) and butane.

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