Synergistic Dimetallic Effects in Propargylic Substitution Reaction Catalyzed by Thiolate-Bridged Diruthenium Complex
- 14 June 2005
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 127 (26), 9428-9438
- https://doi.org/10.1021/ja050298z
Abstract
The origin of unique catalytic activity of a thiolate-bridged diruthenium complex in nucleophilic substitution reactions of propargylic alcohols, which features a diruthenium−allenylidene complex as a key intermediate, was studied with the aid of density functional calculations (B3LYP). Comparison of mono- and diruthenium systems has shown that the rigid but reasonably flexible Ru−Ru core structure plays a critical role in the catalyst turnover step (i.e., dissociative ligand exchange of the product π-complex with the starting propargyl alcohol that goes through a coordinatively unsaturated Ru complex). In the diruthenium system, the energy loss due to coordinative unsaturation can be compensated by reinforcement of the Ru−Ru bond, while such an effect is unavailable in the monoruthenium counterpart. Weaker back-donation ability of the diruthenium complex is also advantageous for dissociation of the π-complex. Thus, ligand exchange takes place smoothly in the diruthenium system to regenerate the reactive species, while the monoruthenium reaction stops at a dead-end Ru product π-complex. The present studies have also shown the important role of protic molecules (e.g., MeOH) that mediate smooth proton transfer in the propargyl alcohol−allenylidene transformation.This publication has 25 references indexed in Scilit:
- Theoretical Studies on Diastereo- and Enantioselective Rhodium-Catalyzed Cyclization of Diazo Compoundvia Intramolecular C-H Bond InsertionAdvanced Synthesis & Catalysis, 2003
- Ruthenium-Catalyzed Carbon−Carbon Bond Formation between Propargylic Alcohols and Alkenes via the Allenylidene-Ene ReactionJournal of the American Chemical Society, 2003
- Synthesis of Diruthenium Complexes Containing Chiral Thiolate-Bridged Ligands and Their Application to Catalytic Propargylic Alkylation of Propargylic Alcohols with AcetoneOrganometallics, 2003
- Ruthenium-Catalyzed Propargylic Alkylation of Propargylic Alcohols with Ketones: Straightforward Synthesis of γ-Keto AcetylenesJournal of the American Chemical Society, 2001
- Novel Propargylic Substitution Reactions Catalyzed by Thiolate-Bridged Diruthenium Complexes via Allenylidene IntermediatesJournal of the American Chemical Society, 2000
- Acetylene .pi.-Coordination, Slippage to .sigma.-Coordination, and 1,2-Hydrogen Migration Taking Place on a Transition Metal. The case of a Ru(II) Complex as Studied by Experiment and ab Initio Molecular Orbital SimulationsJournal of the American Chemical Society, 1994
- [Ru6(Te2)7(CO)12]2-: hydrothermal synthesis of a novel ruthenium-tellurium Ru2+/Te22- cluster and its relationship to RuTe2Journal of the American Chemical Society, 1992
- Thermal decomposition processes for silanolThe Journal of Physical Chemistry, 1990
- Density-functional exchange-energy approximation with correct asymptotic behaviorPhysical Review A, 1988
- Synthesis and structure of [Ru(C3Ph2)(PMe3)2(Cp)][PF6], a cationic diphenylallenylidene complexOrganometallics, 1982