Limits...
Chemistry of a novel zerovalent ruthenium π-acidic alkene complex, Ru (η (6)-1,3,5-cyclooctatriene)(η (2)-dimethyl fumarate)2.

Mitsudo TA, Ura Y, Kondo T - Proc. Jpn. Acad., Ser. B, Phys. Biol. Sci. (2007)

Bottom Line: Complex 1 was shown to be an excellent mother complex for various zerovalent ruthenium complexes.Complex 1 reacts with amines, phosphines or water to give new zerovalent ruthenium complexes with the ligands.The resulting aqua complexes have a water ligand with an oxygen atom that is a chiral center, i.e., ruthenium complexes with a 'chiral water' ligand were prepared and fully characterized.

View Article: PubMed Central - PubMed

Affiliation: Professor Emeritus, Kyoto University.

ABSTRACT
A novel zerovalent ruthenium complex with a π-acidic ligand, Ru(η (6)-cyclooctatriene)(η (2)-dimethyl fumarate)2 (1), was prepared from Ru(η (4)-cyclooctadiene)(η (6)-cyclooctatriene) [Ru(cod)(cot)]. Complex 1 or Ru(cod)(cot) catalyzes various new carbon-carbon bond-forming reactions that include the [2 + 2] cycloaddition of alkenes and alkynes via ruthenacycles, the creation of a new hydrocarbon, pentacyclo[6.6.0.0(2,6).0(3,13).0(10,14)]tetradeca-4,11-diene [PCTD], by dimerization of 2,5-norbornadiene via C-C bond cleavage, and the codimerization of alkynes and/or alkenes. Complex 1 was shown to be an excellent mother complex for various zerovalent ruthenium complexes. Complex 1 reacts with amines, phosphines or water to give new zerovalent ruthenium complexes with the ligands. The resulting aqua complexes have a water ligand with an oxygen atom that is a chiral center, i.e., ruthenium complexes with a 'chiral water' ligand were prepared and fully characterized.

No MeSH data available.


A possible mechanism of the formation of PCTD.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3756878&req=5

f10-83_065: A possible mechanism of the formation of PCTD.

Mentions: Although the mechanism of the dimerization to PCTD is not yet clear, a hypothetical mechanism is as follows (Scheme 3). One 2,5-norbornadiene molecule inserts into a hydrido-ruthenium bond, which could be easily formed by the activation of a C-H bond of the ligands. Successive insertion of another 2,5-norbornadiene between the carbon-ruthenium bond would give intermediate complex 4. A similar complex in which Ln = Cl has been isolated in the reaction of a hydridochlororuthenium complex with 2,5-norbornadiene.36) Further intramolecular insertion of the olefinic part of the ligand in complex 4 between the carbon-ruthenium bond gives complex 5, in which an endo-endo dimer of 2,5-norbornadiene is bound to the ruthenium center with a σ-carbon-ruthenium bond. Oxidative addition of the carbon-carbon bond to the ruthenium complex gives Ru(IV) complex 6, and reductive elimination gives 7. β-Carbon elimination of 7 gives complex 8 and β-hydride elimination gives the product PCTD irreversibly. Dimethyl fumarate or N, N-dimethylacrylamide may be a source of the hydride and also acts as a ligand that controls the electronic density of the ruthenium catalytic center. Especially, reductive elimination would be accelerated by the π-acidic ligand.


Chemistry of a novel zerovalent ruthenium π-acidic alkene complex, Ru (η (6)-1,3,5-cyclooctatriene)(η (2)-dimethyl fumarate)2.

Mitsudo TA, Ura Y, Kondo T - Proc. Jpn. Acad., Ser. B, Phys. Biol. Sci. (2007)

A possible mechanism of the formation of PCTD.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3756878&req=5

f10-83_065: A possible mechanism of the formation of PCTD.
Mentions: Although the mechanism of the dimerization to PCTD is not yet clear, a hypothetical mechanism is as follows (Scheme 3). One 2,5-norbornadiene molecule inserts into a hydrido-ruthenium bond, which could be easily formed by the activation of a C-H bond of the ligands. Successive insertion of another 2,5-norbornadiene between the carbon-ruthenium bond would give intermediate complex 4. A similar complex in which Ln = Cl has been isolated in the reaction of a hydridochlororuthenium complex with 2,5-norbornadiene.36) Further intramolecular insertion of the olefinic part of the ligand in complex 4 between the carbon-ruthenium bond gives complex 5, in which an endo-endo dimer of 2,5-norbornadiene is bound to the ruthenium center with a σ-carbon-ruthenium bond. Oxidative addition of the carbon-carbon bond to the ruthenium complex gives Ru(IV) complex 6, and reductive elimination gives 7. β-Carbon elimination of 7 gives complex 8 and β-hydride elimination gives the product PCTD irreversibly. Dimethyl fumarate or N, N-dimethylacrylamide may be a source of the hydride and also acts as a ligand that controls the electronic density of the ruthenium catalytic center. Especially, reductive elimination would be accelerated by the π-acidic ligand.

Bottom Line: Complex 1 was shown to be an excellent mother complex for various zerovalent ruthenium complexes.Complex 1 reacts with amines, phosphines or water to give new zerovalent ruthenium complexes with the ligands.The resulting aqua complexes have a water ligand with an oxygen atom that is a chiral center, i.e., ruthenium complexes with a 'chiral water' ligand were prepared and fully characterized.

View Article: PubMed Central - PubMed

Affiliation: Professor Emeritus, Kyoto University.

ABSTRACT
A novel zerovalent ruthenium complex with a π-acidic ligand, Ru(η (6)-cyclooctatriene)(η (2)-dimethyl fumarate)2 (1), was prepared from Ru(η (4)-cyclooctadiene)(η (6)-cyclooctatriene) [Ru(cod)(cot)]. Complex 1 or Ru(cod)(cot) catalyzes various new carbon-carbon bond-forming reactions that include the [2 + 2] cycloaddition of alkenes and alkynes via ruthenacycles, the creation of a new hydrocarbon, pentacyclo[6.6.0.0(2,6).0(3,13).0(10,14)]tetradeca-4,11-diene [PCTD], by dimerization of 2,5-norbornadiene via C-C bond cleavage, and the codimerization of alkynes and/or alkenes. Complex 1 was shown to be an excellent mother complex for various zerovalent ruthenium complexes. Complex 1 reacts with amines, phosphines or water to give new zerovalent ruthenium complexes with the ligands. The resulting aqua complexes have a water ligand with an oxygen atom that is a chiral center, i.e., ruthenium complexes with a 'chiral water' ligand were prepared and fully characterized.

No MeSH data available.